1afe61c15SRodney W. Grimes.\" Copyright (c) 1991, 1992, 1993 2afe61c15SRodney W. Grimes.\" The Regents of the University of California. All rights reserved. 3afe61c15SRodney W. Grimes.\" 4afe61c15SRodney W. Grimes.\" Redistribution and use in source and binary forms, with or without 5afe61c15SRodney W. Grimes.\" modification, are permitted provided that the following conditions 6afe61c15SRodney W. Grimes.\" are met: 7afe61c15SRodney W. Grimes.\" 1. Redistributions of source code must retain the above copyright 8afe61c15SRodney W. Grimes.\" notice, this list of conditions and the following disclaimer. 9afe61c15SRodney W. Grimes.\" 2. Redistributions in binary form must reproduce the above copyright 10afe61c15SRodney W. Grimes.\" notice, this list of conditions and the following disclaimer in the 11afe61c15SRodney W. Grimes.\" documentation and/or other materials provided with the distribution. 12dda5b397SEitan Adler.\" 3. Neither the name of the University nor the names of its contributors 13afe61c15SRodney W. Grimes.\" may be used to endorse or promote products derived from this software 14afe61c15SRodney W. Grimes.\" without specific prior written permission. 15afe61c15SRodney W. Grimes.\" 16afe61c15SRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17afe61c15SRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18afe61c15SRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19afe61c15SRodney W. Grimes.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20afe61c15SRodney W. Grimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21afe61c15SRodney W. Grimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22afe61c15SRodney W. Grimes.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23afe61c15SRodney W. Grimes.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24afe61c15SRodney W. Grimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25afe61c15SRodney W. Grimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26afe61c15SRodney W. Grimes.\" SUCH DAMAGE. 27afe61c15SRodney W. Grimes.\" 28afe61c15SRodney W. Grimes.\" @(#)termios.4 8.4 (Berkeley) 4/19/94 297f3dea24SPeter Wemm.\" $FreeBSD$ 30afe61c15SRodney W. Grimes.\" 31*2dcf8c45SMichael Gmelin.Dd June 27, 2020 32afe61c15SRodney W. Grimes.Dt TERMIOS 4 333d45e180SRuslan Ermilov.Os 34afe61c15SRodney W. Grimes.Sh NAME 35afe61c15SRodney W. Grimes.Nm termios 36afe61c15SRodney W. Grimes.Nd general terminal line discipline 37afe61c15SRodney W. Grimes.Sh SYNOPSIS 3832eef9aeSRuslan Ermilov.In termios.h 39afe61c15SRodney W. Grimes.Sh DESCRIPTION 40afe61c15SRodney W. GrimesThis describes a general terminal line discipline that is 41afe61c15SRodney W. Grimessupported on tty asynchronous communication ports. 42afe61c15SRodney W. Grimes.Ss Opening a Terminal Device File 43afe61c15SRodney W. GrimesWhen a terminal file is opened, it normally causes the process to wait 44b5e7e999SRuslan Ermilovuntil a connection is established. 45b5e7e999SRuslan ErmilovFor most hardware, the presence 46afe61c15SRodney W. Grimesof a connection is indicated by the assertion of the hardware 47d0353b83SRuslan Ermilov.Dv CARRIER 48d0353b83SRuslan Ermilovline. 49afe61c15SRodney W. GrimesIf the termios structure associated with the terminal file has the 50afe61c15SRodney W. Grimes.Dv CLOCAL 51afe61c15SRodney W. Grimesflag set in the cflag, or if the 52afe61c15SRodney W. Grimes.Dv O_NONBLOCK 53afe61c15SRodney W. Grimesflag is set 54afe61c15SRodney W. Grimesin the 55afe61c15SRodney W. Grimes.Xr open 2 56afe61c15SRodney W. Grimescall, then the open will succeed even without 57afe61c15SRodney W. Grimesa connection being present. 58afe61c15SRodney W. GrimesIn practice, applications 59afe61c15SRodney W. Grimesseldom open these files; they are opened by special programs, such 60afe61c15SRodney W. Grimesas 6176acea15SEd Maste.Xr getty 8 , 62afe61c15SRodney W. Grimesand become 63afe61c15SRodney W. Grimesan application's standard input, output, and error files. 64afe61c15SRodney W. Grimes.Ss Job Control in a Nutshell 65afe61c15SRodney W. GrimesEvery process is associated with a particular process group and session. 66afe61c15SRodney W. GrimesThe grouping is hierarchical: every member of a particular process group is a 67b5e7e999SRuslan Ermilovmember of the same session. 68b5e7e999SRuslan ErmilovThis structuring is used in managing groups 69afe61c15SRodney W. Grimesof related processes for purposes of 70afe61c15SRodney W. Grimes.\" .Gw "job control" ; 71afe61c15SRodney W. Grimes.Em "job control" ; 72afe61c15SRodney W. Grimesthat is, the 73afe61c15SRodney W. Grimesability from the keyboard (or from program control) to simultaneously 74afe61c15SRodney W. Grimesstop or restart 75afe61c15SRodney W. Grimesa complex command (a command composed of one or more related 76b5e7e999SRuslan Ermilovprocesses). 77b5e7e999SRuslan ErmilovThe grouping into process groups allows delivering 78afe61c15SRodney W. Grimesof signals that stop or start the group as a whole, along with 79afe61c15SRodney W. Grimesarbitrating which process group has access to the single controlling 80b5e7e999SRuslan Ermilovterminal. 81b5e7e999SRuslan ErmilovThe grouping at a higher layer into sessions is to restrict 82afe61c15SRodney W. Grimesthe job control related signals and system calls to within processes 83b5e7e999SRuslan Ermilovresulting from a particular instance of a 84b5e7e999SRuslan Ermilov.Dq login . 85b5e7e999SRuslan ErmilovTypically, a session 86afe61c15SRodney W. Grimesis created when a user logs in, and the login terminal is setup 87afe61c15SRodney W. Grimesto be the controlling terminal; all processes spawned from that 88afe61c15SRodney W. Grimeslogin shell are in the same session, and inherit the controlling 89afe61c15SRodney W. Grimesterminal. 90edf0e5b3SMike Pritchard.Pp 91afe61c15SRodney W. GrimesA job control shell 92afe61c15SRodney W. Grimesoperating interactively (that is, reading commands from a terminal) 93afe61c15SRodney W. Grimesnormally groups related processes together by placing them into the 94b5e7e999SRuslan Ermilovsame process group. 95b5e7e999SRuslan ErmilovA set of processes in the same process group 96b5e7e999SRuslan Ermilovis collectively referred to as a 97b5e7e999SRuslan Ermilov.Dq job . 98b5e7e999SRuslan ErmilovWhen the foreground process 99afe61c15SRodney W. Grimesgroup of the terminal is the same as the process group of a particular 100b5e7e999SRuslan Ermilovjob, that job is said to be in the 101b5e7e999SRuslan Ermilov.Dq foreground . 102b5e7e999SRuslan ErmilovWhen the process group of the terminal is different from the process group of 103afe61c15SRodney W. Grimesa job (but is still the controlling terminal), that job is said 104b5e7e999SRuslan Ermilovto be in the 105b5e7e999SRuslan Ermilov.Dq background . 106b5e7e999SRuslan ErmilovNormally the 107afe61c15SRodney W. Grimesshell reads a command and starts the job that implements that 108b5e7e999SRuslan Ermilovcommand. 109b5e7e999SRuslan ErmilovIf the command is to be started in the foreground (typical), it 110afe61c15SRodney W. Grimessets the process group of the terminal to the process group 111afe61c15SRodney W. Grimesof the started job, waits for the job to complete, and then 112afe61c15SRodney W. Grimessets the process group of the terminal back to its own process 113b5e7e999SRuslan Ermilovgroup (it puts itself into the foreground). 114b5e7e999SRuslan ErmilovIf the job is to 115afe61c15SRodney W. Grimesbe started in the background (as denoted by the shell operator "&"), 1160227791bSRuslan Ermilovit never changes the process group of the terminal and does not 117afe61c15SRodney W. Grimeswait for the job to complete (that is, it immediately attempts to read the next 118b5e7e999SRuslan Ermilovcommand). 119b5e7e999SRuslan ErmilovIf the job is started in the foreground, the user may 120afe61c15SRodney W. Grimestype a key (usually 121afe61c15SRodney W. Grimes.Ql \&^Z ) 122afe61c15SRodney W. Grimeswhich generates the terminal stop signal 123afe61c15SRodney W. Grimes.Pq Dv SIGTSTP 124db3357b8SSheldon Hearnand has the effect of stopping the entire job. 125afe61c15SRodney W. GrimesThe shell will notice that the job stopped, and will resume running after 126afe61c15SRodney W. Grimesplacing itself in the foreground. 127afe61c15SRodney W. GrimesThe shell also has commands for placing stopped jobs in the background, 128afe61c15SRodney W. Grimesand for placing stopped or background jobs into the foreground. 129afe61c15SRodney W. Grimes.Ss Orphaned Process Groups 130afe61c15SRodney W. GrimesAn orphaned process group is a process group that has no process 131afe61c15SRodney W. Grimeswhose parent is in a different process group, yet is in the same 132b5e7e999SRuslan Ermilovsession. 1330227791bSRuslan ErmilovConceptually it means a process group that does not have 134b5e7e999SRuslan Ermilova parent that could do anything if it were to be stopped. 135b5e7e999SRuslan ErmilovFor example, 136afe61c15SRodney W. Grimesthe initial login shell is typically in an orphaned process group. 137afe61c15SRodney W. GrimesOrphaned process groups are immune to keyboard generated stop 138afe61c15SRodney W. Grimessignals and job control signals resulting from reads or writes to the 139afe61c15SRodney W. Grimescontrolling terminal. 140afe61c15SRodney W. Grimes.Ss The Controlling Terminal 141b5e7e999SRuslan ErmilovA terminal may belong to a process as its controlling terminal. 142b5e7e999SRuslan ErmilovEach 143afe61c15SRodney W. Grimesprocess of a session that has a controlling terminal has the same 144b5e7e999SRuslan Ermilovcontrolling terminal. 145b5e7e999SRuslan ErmilovA terminal may be the controlling terminal for at 146b5e7e999SRuslan Ermilovmost one session. 147b5e7e999SRuslan ErmilovThe controlling terminal for a session is allocated by 148afe61c15SRodney W. Grimesthe session leader by issuing the 149afe61c15SRodney W. Grimes.Dv TIOCSCTTY 1505203edcdSRuslan Ermilovioctl. 1515203edcdSRuslan ErmilovA controlling terminal 152afe61c15SRodney W. Grimesis never acquired by merely opening a terminal device file. 153afe61c15SRodney W. GrimesWhen a controlling terminal becomes 154afe61c15SRodney W. Grimesassociated with a session, its foreground process group is set to 155afe61c15SRodney W. Grimesthe process group of the session leader. 156afe61c15SRodney W. Grimes.Pp 157afe61c15SRodney W. GrimesThe controlling terminal is inherited by a child process during a 158afe61c15SRodney W. Grimes.Xr fork 2 159b5e7e999SRuslan Ermilovfunction call. 160b5e7e999SRuslan ErmilovA process relinquishes its controlling terminal when it 161afe61c15SRodney W. Grimescreates a new session with the 162929f3023SJoseph Koshy.Xr setsid 2 163afe61c15SRodney W. Grimesfunction; other processes 164afe61c15SRodney W. Grimesremaining in the old session that had this terminal as their controlling 165afe61c15SRodney W. Grimesterminal continue to have it. 166afe61c15SRodney W. GrimesA process does not relinquish its 167afe61c15SRodney W. Grimescontrolling terminal simply by closing all of its file descriptors 168afe61c15SRodney W. Grimesassociated with the controlling terminal if other processes continue to 169afe61c15SRodney W. Grimeshave it open. 170afe61c15SRodney W. Grimes.Pp 171afe61c15SRodney W. GrimesWhen a controlling process terminates, the controlling terminal is 172afe61c15SRodney W. Grimesdisassociated from the current session, allowing it to be acquired by a 173b5e7e999SRuslan Ermilovnew session leader. 174b5e7e999SRuslan ErmilovSubsequent access to the terminal by other processes 175afe61c15SRodney W. Grimesin the earlier session will be denied, with attempts to access the 176afe61c15SRodney W. Grimesterminal treated as if modem disconnect had been sensed. 177afe61c15SRodney W. Grimes.Ss Terminal Access Control 178afe61c15SRodney W. GrimesIf a process is in the foreground process group of its controlling 179afe61c15SRodney W. Grimesterminal, read operations are allowed. 180afe61c15SRodney W. GrimesAny attempts by a process 181afe61c15SRodney W. Grimesin a background process group to read from its controlling terminal 182afe61c15SRodney W. Grimescauses a 183afe61c15SRodney W. Grimes.Dv SIGTTIN 184afe61c15SRodney W. Grimessignal to be sent to 185afe61c15SRodney W. Grimesthe process's group 186afe61c15SRodney W. Grimesunless one of the 1875203edcdSRuslan Ermilovfollowing special cases apply: if the reading process is ignoring or 188afe61c15SRodney W. Grimesblocking the 189f167d7fbSSheldon Hearn.Dv SIGTTIN 190f167d7fbSSheldon Hearnsignal, or if the process group of the reading 191afe61c15SRodney W. Grimesprocess is orphaned, the 192afe61c15SRodney W. Grimes.Xr read 2 193afe61c15SRodney W. Grimesreturns -1 with 19450d922a0SGlen Barber.Va errno 19550d922a0SGlen Barberset to 196b92a189eSRuslan Ermilov.Er EIO 197afe61c15SRodney W. Grimesand no 1985203edcdSRuslan Ermilovsignal is sent. 1995203edcdSRuslan ErmilovThe default action of the 200afe61c15SRodney W. Grimes.Dv SIGTTIN 201afe61c15SRodney W. Grimessignal is to stop the 202afe61c15SRodney W. Grimesprocess to which it is sent. 203afe61c15SRodney W. Grimes.Pp 204afe61c15SRodney W. GrimesIf a process is in the foreground process group of its controlling 205afe61c15SRodney W. Grimesterminal, write operations are allowed. 206afe61c15SRodney W. GrimesAttempts by a process in a background process group to write to its 207afe61c15SRodney W. Grimescontrolling terminal will cause the process group to be sent a 208afe61c15SRodney W. Grimes.Dv SIGTTOU 2095203edcdSRuslan Ermilovsignal unless one of the following special cases apply: if 210afe61c15SRodney W. Grimes.Dv TOSTOP 211afe61c15SRodney W. Grimesis not 212afe61c15SRodney W. Grimesset, or if 213afe61c15SRodney W. Grimes.Dv TOSTOP 214afe61c15SRodney W. Grimesis set and the process is ignoring or blocking the 215afe61c15SRodney W. Grimes.Dv SIGTTOU 216afe61c15SRodney W. Grimessignal, the process is allowed to write to the terminal and the 217afe61c15SRodney W. Grimes.Dv SIGTTOU 218b5e7e999SRuslan Ermilovsignal is not sent. 219b5e7e999SRuslan ErmilovIf 220afe61c15SRodney W. Grimes.Dv TOSTOP 221afe61c15SRodney W. Grimesis set, and the process group of 222afe61c15SRodney W. Grimesthe writing process is orphaned, and the writing process is not ignoring 223afe61c15SRodney W. Grimesor blocking 224afe61c15SRodney W. Grimes.Dv SIGTTOU , 225afe61c15SRodney W. Grimesthe 226edf0e5b3SMike Pritchard.Xr write 2 227afe61c15SRodney W. Grimesreturns -1 with 228afe61c15SRodney W. Grimeserrno set to 229b92a189eSRuslan Ermilov.Er EIO 230afe61c15SRodney W. Grimesand no signal is sent. 231afe61c15SRodney W. Grimes.Pp 232afe61c15SRodney W. GrimesCertain calls that set terminal parameters are treated in the same 233afe61c15SRodney W. Grimesfashion as write, except that 234afe61c15SRodney W. Grimes.Dv TOSTOP 235afe61c15SRodney W. Grimesis ignored; that is, the effect is 236afe61c15SRodney W. Grimesidentical to that of terminal writes when 237afe61c15SRodney W. Grimes.Dv TOSTOP 238afe61c15SRodney W. Grimesis set. 239afe61c15SRodney W. Grimes.Ss Input Processing and Reading Data 240afe61c15SRodney W. GrimesA terminal device associated with a terminal device file may operate in 241afe61c15SRodney W. Grimesfull-duplex mode, so that data may arrive even while output is occurring. 242afe61c15SRodney W. GrimesEach terminal device file has associated with it an input queue, into 243afe61c15SRodney W. Grimeswhich incoming data is stored by the system before being read by a 2445203edcdSRuslan Ermilovprocess. 2455203edcdSRuslan ErmilovThe system imposes a limit, 246afe61c15SRodney W. Grimes.Pf \&{ Dv MAX_INPUT Ns \&} , 247afe61c15SRodney W. Grimeson the number of 248b5e7e999SRuslan Ermilovbytes that may be stored in the input queue. 249b5e7e999SRuslan ErmilovThe behavior of the system 250afe61c15SRodney W. Grimeswhen this limit is exceeded depends on the setting of the 251afe61c15SRodney W. Grimes.Dv IMAXBEL 252afe61c15SRodney W. Grimesflag in the termios 253afe61c15SRodney W. Grimes.Fa c_iflag . 254afe61c15SRodney W. GrimesIf this flag is set, the terminal 255afe61c15SRodney W. Grimesis sent an 256afe61c15SRodney W. Grimes.Tn ASCII 257afe61c15SRodney W. Grimes.Dv BEL 258afe61c15SRodney W. Grimescharacter each time a character is received 259b5e7e999SRuslan Ermilovwhile the input queue is full. 260b5e7e999SRuslan ErmilovOtherwise, the input queue is flushed upon receiving the character. 261afe61c15SRodney W. Grimes.Pp 262afe61c15SRodney W. GrimesTwo general kinds of input processing are available, determined by 263afe61c15SRodney W. Grimeswhether the terminal device file is in canonical mode or noncanonical 2646d249eeeSSheldon Hearnmode. 2656d249eeeSSheldon HearnAdditionally, 266afe61c15SRodney W. Grimesinput characters are processed according to the 267afe61c15SRodney W. Grimes.Fa c_iflag 268afe61c15SRodney W. Grimesand 269afe61c15SRodney W. Grimes.Fa c_lflag 2705203edcdSRuslan Ermilovfields. 2715203edcdSRuslan ErmilovSuch processing can include echoing, which 272afe61c15SRodney W. Grimesin general means transmitting input characters immediately back to the 273b5e7e999SRuslan Ermilovterminal when they are received from the terminal. 274b5e7e999SRuslan ErmilovThis is useful for terminals that can operate in full-duplex mode. 275afe61c15SRodney W. Grimes.Pp 276afe61c15SRodney W. GrimesThe manner in which data is provided to a process reading from a terminal 277afe61c15SRodney W. Grimesdevice file is dependent on whether the terminal device file is in 278afe61c15SRodney W. Grimescanonical or noncanonical mode. 279afe61c15SRodney W. Grimes.Pp 280afe61c15SRodney W. GrimesAnother dependency is whether the 281afe61c15SRodney W. Grimes.Dv O_NONBLOCK 282afe61c15SRodney W. Grimesflag is set by 283edf0e5b3SMike Pritchard.Xr open 2 284afe61c15SRodney W. Grimesor 285edf0e5b3SMike Pritchard.Xr fcntl 2 . 286afe61c15SRodney W. GrimesIf the 287afe61c15SRodney W. Grimes.Dv O_NONBLOCK 288afe61c15SRodney W. Grimesflag is clear, then the read request is 289b5e7e999SRuslan Ermilovblocked until data is available or a signal has been received. 290b5e7e999SRuslan ErmilovIf the 291afe61c15SRodney W. Grimes.Dv O_NONBLOCK 292afe61c15SRodney W. Grimesflag is set, then the read request is completed, without 293afe61c15SRodney W. Grimesblocking, in one of three ways: 294afe61c15SRodney W. Grimes.Bl -enum -offset indent 295afe61c15SRodney W. Grimes.It 296afe61c15SRodney W. GrimesIf there is enough data available to satisfy the entire request, 297afe61c15SRodney W. Grimesand the read completes successfully the number of 298afe61c15SRodney W. Grimesbytes read is returned. 299afe61c15SRodney W. Grimes.It 300afe61c15SRodney W. GrimesIf there is not enough data available to satisfy the entire 301afe61c15SRodney W. Grimesrequest, and the read completes successfully, having read as 302afe61c15SRodney W. Grimesmuch data as possible, the number of bytes read is returned. 303afe61c15SRodney W. Grimes.It 304afe61c15SRodney W. GrimesIf there is no data available, the read returns -1, with 305afe61c15SRodney W. Grimeserrno set to 306afe61c15SRodney W. Grimes.Er EAGAIN . 307afe61c15SRodney W. Grimes.El 308afe61c15SRodney W. Grimes.Pp 309afe61c15SRodney W. GrimesWhen data is available depends on whether the input processing mode is 310afe61c15SRodney W. Grimescanonical or noncanonical. 311afe61c15SRodney W. Grimes.Ss Canonical Mode Input Processing 312afe61c15SRodney W. GrimesIn canonical mode input processing, terminal input is processed in units 3135203edcdSRuslan Ermilovof lines. 3145203edcdSRuslan ErmilovA line is delimited by a newline 315afe61c15SRodney W. Grimes.Ql \&\en 316afe61c15SRodney W. Grimescharacter, an end-of-file 317afe61c15SRodney W. Grimes.Pq Dv EOF 318afe61c15SRodney W. Grimescharacter, or an end-of-line 319afe61c15SRodney W. Grimes.Pq Dv EOL 3205203edcdSRuslan Ermilovcharacter. 3215203edcdSRuslan ErmilovSee the 322afe61c15SRodney W. Grimes.Sx "Special Characters" 323afe61c15SRodney W. Grimessection for 324afe61c15SRodney W. Grimesmore information on 325afe61c15SRodney W. Grimes.Dv EOF 326afe61c15SRodney W. Grimesand 327afe61c15SRodney W. Grimes.Dv EOL . 328afe61c15SRodney W. GrimesThis means that a read request will 329afe61c15SRodney W. Grimesnot return until an entire line has been typed, or a signal has been 330b5e7e999SRuslan Ermilovreceived. 331b5e7e999SRuslan ErmilovAlso, no matter how many bytes are requested in the read call, 332b5e7e999SRuslan Ermilovat most one line is returned. 333b5e7e999SRuslan ErmilovIt is not, however, necessary to 334afe61c15SRodney W. Grimesread a whole line at once; any number of bytes, even one, may be 335afe61c15SRodney W. Grimesrequested in a read without losing information. 336afe61c15SRodney W. Grimes.Pp 337afe61c15SRodney W. Grimes.Pf \&{ Dv MAX_CANON Ns \&} 338afe61c15SRodney W. Grimesis a limit on the 339afe61c15SRodney W. Grimesnumber of bytes in a line. 340afe61c15SRodney W. GrimesThe behavior of the system when this limit is 341afe61c15SRodney W. Grimesexceeded is the same as when the input queue limit 342afe61c15SRodney W. Grimes.Pf \&{ Dv MAX_INPUT Ns \&} , 343afe61c15SRodney W. Grimesis exceeded. 344afe61c15SRodney W. Grimes.Pp 345afe61c15SRodney W. GrimesErase and kill processing occur when either of two special characters, 346afe61c15SRodney W. Grimesthe 347afe61c15SRodney W. Grimes.Dv ERASE 348afe61c15SRodney W. Grimesand 349afe61c15SRodney W. Grimes.Dv KILL 350afe61c15SRodney W. Grimescharacters (see the 3516e679990SPawel Jakub Dawidek.Sx "Special Characters" 3526e679990SPawel Jakub Dawideksection), is received. 353afe61c15SRodney W. GrimesThis processing affects data in the input queue that has not yet been 354afe61c15SRodney W. Grimesdelimited by a newline 355afe61c15SRodney W. Grimes.Dv NL , 356afe61c15SRodney W. Grimes.Dv EOF , 357afe61c15SRodney W. Grimesor 358afe61c15SRodney W. Grimes.Dv EOL 3595203edcdSRuslan Ermilovcharacter. 3605203edcdSRuslan ErmilovThis un-delimited 361b5e7e999SRuslan Ermilovdata makes up the current line. 362b5e7e999SRuslan ErmilovThe 363afe61c15SRodney W. Grimes.Dv ERASE 364afe61c15SRodney W. Grimescharacter deletes the last 365b5e7e999SRuslan Ermilovcharacter in the current line, if there is any. 366b5e7e999SRuslan ErmilovThe 367afe61c15SRodney W. Grimes.Dv KILL 368afe61c15SRodney W. Grimescharacter 369b5e7e999SRuslan Ermilovdeletes all data in the current line, if there is any. 370b5e7e999SRuslan ErmilovThe 371afe61c15SRodney W. Grimes.Dv ERASE 372afe61c15SRodney W. Grimesand 373afe61c15SRodney W. Grimes.Dv KILL 374afe61c15SRodney W. Grimescharacters have no effect if there is no data in the current line. 375afe61c15SRodney W. GrimesThe 376afe61c15SRodney W. Grimes.Dv ERASE 377afe61c15SRodney W. Grimesand 378afe61c15SRodney W. Grimes.Dv KILL 379afe61c15SRodney W. Grimescharacters themselves are not placed in the input 380afe61c15SRodney W. Grimesqueue. 381afe61c15SRodney W. Grimes.Ss Noncanonical Mode Input Processing 382afe61c15SRodney W. GrimesIn noncanonical mode input processing, input bytes are not assembled into 383b5e7e999SRuslan Ermilovlines, and erase and kill processing does not occur. 384b5e7e999SRuslan ErmilovThe values of the 385ed7922d3SMike Pritchard.Dv VMIN 386afe61c15SRodney W. Grimesand 387ed7922d3SMike Pritchard.Dv VTIME 388afe61c15SRodney W. Grimesmembers of the 389afe61c15SRodney W. Grimes.Fa c_cc 390afe61c15SRodney W. Grimesarray are used to determine how to 391afe61c15SRodney W. Grimesprocess the bytes received. 392afe61c15SRodney W. Grimes.Pp 3935f1376d7SMike Pritchard.Dv MIN 394afe61c15SRodney W. Grimesrepresents the minimum number of bytes that should be received when 395afe61c15SRodney W. Grimesthe 396edf0e5b3SMike Pritchard.Xr read 2 397afe61c15SRodney W. Grimesfunction successfully returns. 3985f1376d7SMike Pritchard.Dv TIME 399afe61c15SRodney W. Grimesis a timer of 0.1 second 400afe61c15SRodney W. Grimesgranularity that is used to time out bursty and short term data 4015203edcdSRuslan Ermilovtransmissions. 4025203edcdSRuslan ErmilovIf 4035f1376d7SMike Pritchard.Dv MIN 404afe61c15SRodney W. Grimesis greater than 405afe61c15SRodney W. Grimes.Dv \&{ Dv MAX_INPUT Ns \&} , 406afe61c15SRodney W. Grimesthe response to the 407b5e7e999SRuslan Ermilovrequest is undefined. 408b5e7e999SRuslan ErmilovThe four possible values for 4095f1376d7SMike Pritchard.Dv MIN 410afe61c15SRodney W. Grimesand 4115f1376d7SMike Pritchard.Dv TIME 412afe61c15SRodney W. Grimesand 413afe61c15SRodney W. Grimestheir interactions are described below. 4145f1376d7SMike Pritchard.Ss "Case A: MIN > 0, TIME > 0" 415afe61c15SRodney W. GrimesIn this case 4165f1376d7SMike Pritchard.Dv TIME 417afe61c15SRodney W. Grimesserves as an inter-byte timer and is activated after 418b5e7e999SRuslan Ermilovthe first byte is received. 419b5e7e999SRuslan ErmilovSince it is an inter-byte timer, it is reset 420b5e7e999SRuslan Ermilovafter a byte is received. 421b5e7e999SRuslan ErmilovThe interaction between 4225f1376d7SMike Pritchard.Dv MIN 423afe61c15SRodney W. Grimesand 4245f1376d7SMike Pritchard.Dv TIME 425afe61c15SRodney W. Grimesis as 426afe61c15SRodney W. Grimesfollows: as soon as one byte is received, the inter-byte timer is 4275203edcdSRuslan Ermilovstarted. 4285203edcdSRuslan ErmilovIf 4295f1376d7SMike Pritchard.Dv MIN 430afe61c15SRodney W. Grimesbytes are received before the inter-byte timer expires 431afe61c15SRodney W. Grimes(remember that the timer is reset upon receipt of each byte), the read is 432b5e7e999SRuslan Ermilovsatisfied. 433b5e7e999SRuslan ErmilovIf the timer expires before 4345f1376d7SMike Pritchard.Dv MIN 435afe61c15SRodney W. Grimesbytes are received, the 436b5e7e999SRuslan Ermilovcharacters received to that point are returned to the user. 437b5e7e999SRuslan ErmilovNote that if 4385f1376d7SMike Pritchard.Dv TIME 439afe61c15SRodney W. Grimesexpires at least one byte is returned because the timer would 440b5e7e999SRuslan Ermilovnot have been enabled unless a byte was received. 441b5e7e999SRuslan ErmilovIn this case 4425f1376d7SMike Pritchard.Pf \&( Dv MIN 443afe61c15SRodney W. Grimes> 0, 4445f1376d7SMike Pritchard.Dv TIME 445afe61c15SRodney W. Grimes> 0) the read blocks until the 4465f1376d7SMike Pritchard.Dv MIN 447afe61c15SRodney W. Grimesand 4485f1376d7SMike Pritchard.Dv TIME 449afe61c15SRodney W. Grimesmechanisms are 450b5e7e999SRuslan Ermilovactivated by the receipt of the first byte, or a signal is received. 451b5e7e999SRuslan ErmilovIf data is in the buffer at the time of the 452edf0e5b3SMike Pritchard.Fn read , 453edf0e5b3SMike Pritchardthe result is as 454edf0e5b3SMike Pritchardif data had been received immediately after the 455edf0e5b3SMike Pritchard.Fn read . 4565f1376d7SMike Pritchard.Ss "Case B: MIN > 0, TIME = 0" 457afe61c15SRodney W. GrimesIn this case, since the value of 4585f1376d7SMike Pritchard.Dv TIME 459afe61c15SRodney W. Grimesis zero, the timer plays no role 460afe61c15SRodney W. Grimesand only 4615f1376d7SMike Pritchard.Dv MIN 462b5e7e999SRuslan Ermilovis significant. 463b5e7e999SRuslan ErmilovA pending read is not satisfied until 4645f1376d7SMike Pritchard.Dv MIN 465afe61c15SRodney W. Grimesbytes are received (i.e., the pending read blocks until 4665f1376d7SMike Pritchard.Dv MIN 467afe61c15SRodney W. Grimesbytes 468b5e7e999SRuslan Ermilovare received), or a signal is received. 469b5e7e999SRuslan ErmilovA program that uses this case to read record-based terminal 470afe61c15SRodney W. Grimes.Dv I/O 471afe61c15SRodney W. Grimesmay block indefinitely in the read 472afe61c15SRodney W. Grimesoperation. 4735f1376d7SMike Pritchard.Ss "Case C: MIN = 0, TIME > 0" 474afe61c15SRodney W. GrimesIn this case, since 4755f1376d7SMike Pritchard.Dv MIN 476afe61c15SRodney W. Grimes= 0, 4775f1376d7SMike Pritchard.Dv TIME 478afe61c15SRodney W. Grimesno longer represents an inter-byte 479b5e7e999SRuslan Ermilovtimer. 480b5e7e999SRuslan ErmilovIt now serves as a read timer that is activated as soon as the 481b5e7e999SRuslan Ermilovread function is processed. 482b5e7e999SRuslan ErmilovA read is satisfied as soon as a single 483b5e7e999SRuslan Ermilovbyte is received or the read timer expires. 484b5e7e999SRuslan ErmilovNote that in this case if the timer expires, no bytes are returned. 485b5e7e999SRuslan ErmilovIf the timer does not 486afe61c15SRodney W. Grimesexpire, the only way the read can be satisfied is if a byte is received. 487afe61c15SRodney W. GrimesIn this case the read will not block indefinitely waiting for a byte; if 488afe61c15SRodney W. Grimesno byte is received within 4895f1376d7SMike Pritchard.Dv TIME Ns *0.1 490afe61c15SRodney W. Grimesseconds after the read is initiated, 491b5e7e999SRuslan Ermilovthe read returns a value of zero, having read no data. 492b5e7e999SRuslan ErmilovIf data is 493afe61c15SRodney W. Grimesin the buffer at the time of the read, the timer is started as if 494afe61c15SRodney W. Grimesdata had been received immediately after the read. 4955f1376d7SMike Pritchard.Ss Case D: MIN = 0, TIME = 0 496afe61c15SRodney W. GrimesThe minimum of either the number of bytes requested or the number of 497afe61c15SRodney W. Grimesbytes currently available is returned without waiting for more 498b5e7e999SRuslan Ermilovbytes to be input. 499b5e7e999SRuslan ErmilovIf no characters are available, read returns a 500afe61c15SRodney W. Grimesvalue of zero, having read no data. 501afe61c15SRodney W. Grimes.Ss Writing Data and Output Processing 502afe61c15SRodney W. GrimesWhen a process writes one or more bytes to a terminal device file, they 503afe61c15SRodney W. Grimesare processed according to the 504afe61c15SRodney W. Grimes.Fa c_oflag 505afe61c15SRodney W. Grimesfield (see the 5066e679990SPawel Jakub Dawidek.Sx "Output Modes" 5075203edcdSRuslan Ermilovsection). 5085203edcdSRuslan ErmilovThe 509afe61c15SRodney W. Grimesimplementation may provide a buffering mechanism; as such, when a call to 510edf0e5b3SMike Pritchard.Fn write 511edf0e5b3SMike Pritchardcompletes, all of the bytes written have been scheduled for 512afe61c15SRodney W. Grimestransmission to the device, but the transmission will not necessarily 513afe61c15SRodney W. Grimeshave been completed. 514afe61c15SRodney W. Grimes.\" See also .Sx "6.4.2" for the effects of 515afe61c15SRodney W. Grimes.\" .Dv O_NONBLOCK 516afe61c15SRodney W. Grimes.\" on write. 517afe61c15SRodney W. Grimes.Ss Special Characters 518afe61c15SRodney W. GrimesCertain characters have special functions on input or output or both. 519afe61c15SRodney W. GrimesThese functions are summarized as follows: 520afe61c15SRodney W. Grimes.Bl -tag -width indent 521afe61c15SRodney W. Grimes.It Dv INTR 522afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 523afe61c15SRodney W. Grimes.Dv ISIG 524afe61c15SRodney W. Grimesflag (see the 525afe61c15SRodney W. Grimes.Sx "Local Modes" 526b5e7e999SRuslan Ermilovsection) is enabled. 527b5e7e999SRuslan ErmilovGenerates a 528afe61c15SRodney W. Grimes.Dv SIGINT 529afe61c15SRodney W. Grimessignal which is sent to all processes in the foreground 530afe61c15SRodney W. Grimesprocess group for which the terminal is the controlling 5315203edcdSRuslan Ermilovterminal. 5325203edcdSRuslan ErmilovIf 533afe61c15SRodney W. Grimes.Dv ISIG 534afe61c15SRodney W. Grimesis set, the 535afe61c15SRodney W. Grimes.Dv INTR 536afe61c15SRodney W. Grimescharacter is 537afe61c15SRodney W. Grimesdiscarded when processed. 538afe61c15SRodney W. Grimes.It Dv QUIT 539afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 540afe61c15SRodney W. Grimes.Dv ISIG 541b5e7e999SRuslan Ermilovflag is enabled. 542b5e7e999SRuslan ErmilovGenerates a 543afe61c15SRodney W. Grimes.Dv SIGQUIT 544afe61c15SRodney W. Grimessignal which is 545afe61c15SRodney W. Grimessent to all processes in the foreground process group 546b5e7e999SRuslan Ermilovfor which the terminal is the controlling terminal. 547b5e7e999SRuslan ErmilovIf 548afe61c15SRodney W. Grimes.Dv ISIG 549afe61c15SRodney W. Grimesis set, the 550afe61c15SRodney W. Grimes.Dv QUIT 551afe61c15SRodney W. Grimescharacter is discarded when 552afe61c15SRodney W. Grimesprocessed. 553afe61c15SRodney W. Grimes.It Dv ERASE 554afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 555afe61c15SRodney W. Grimes.Dv ICANON 556b5e7e999SRuslan Ermilovflag is set. 557b5e7e999SRuslan ErmilovErases the last character in the 558afe61c15SRodney W. Grimescurrent line; see 559afe61c15SRodney W. Grimes.Sx "Canonical Mode Input Processing" . 560afe61c15SRodney W. GrimesIt does not erase beyond 561afe61c15SRodney W. Grimesthe start of a line, as delimited by an 562afe61c15SRodney W. Grimes.Dv NL , 563afe61c15SRodney W. Grimes.Dv EOF , 564afe61c15SRodney W. Grimesor 565afe61c15SRodney W. Grimes.Dv EOL 566b5e7e999SRuslan Ermilovcharacter. 567b5e7e999SRuslan ErmilovIf 568afe61c15SRodney W. Grimes.Dv ICANON 569afe61c15SRodney W. Grimesis set, the 570afe61c15SRodney W. Grimes.Dv ERASE 571afe61c15SRodney W. Grimescharacter is 572afe61c15SRodney W. Grimesdiscarded when processed. 573afe61c15SRodney W. Grimes.It Dv KILL 574afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 575afe61c15SRodney W. Grimes.Dv ICANON 576b5e7e999SRuslan Ermilovflag is set. 577b5e7e999SRuslan ErmilovDeletes the entire line, as 578afe61c15SRodney W. Grimesdelimited by a 579afe61c15SRodney W. Grimes.Dv NL , 580afe61c15SRodney W. Grimes.Dv EOF , 581afe61c15SRodney W. Grimesor 582afe61c15SRodney W. Grimes.Dv EOL 583b5e7e999SRuslan Ermilovcharacter. 584b5e7e999SRuslan ErmilovIf 585afe61c15SRodney W. Grimes.Dv ICANON 586afe61c15SRodney W. Grimesis set, the 587afe61c15SRodney W. Grimes.Dv KILL 588afe61c15SRodney W. Grimescharacter is discarded when processed. 589afe61c15SRodney W. Grimes.It Dv EOF 590afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 591afe61c15SRodney W. Grimes.Dv ICANON 592b5e7e999SRuslan Ermilovflag is set. 593b5e7e999SRuslan ErmilovWhen received, all the bytes 594afe61c15SRodney W. Grimeswaiting to be read are immediately passed to the 595afe61c15SRodney W. Grimesprocess, without waiting for a newline, and the 596afe61c15SRodney W. Grimes.Dv EOF 597b5e7e999SRuslan Ermilovis discarded. 598b5e7e999SRuslan ErmilovThus, if there are no bytes waiting (that is, the 599afe61c15SRodney W. Grimes.Dv EOF 600afe61c15SRodney W. Grimesoccurred at the beginning of a line), a byte 601edf0e5b3SMike Pritchardcount of zero is returned from the 602edf0e5b3SMike Pritchard.Fn read , 603b5e7e999SRuslan Ermilovrepresenting an end-of-file indication. 604b5e7e999SRuslan ErmilovIf 605afe61c15SRodney W. Grimes.Dv ICANON 606afe61c15SRodney W. Grimesis 607afe61c15SRodney W. Grimesset, the 608afe61c15SRodney W. Grimes.Dv EOF 609afe61c15SRodney W. Grimescharacter is discarded when processed. 610081cb6b3SMark Ovens.It Dv NL 611afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 612afe61c15SRodney W. Grimes.Dv ICANON 613b5e7e999SRuslan Ermilovflag is set. 614b5e7e999SRuslan ErmilovIt is the line delimiter 615afe61c15SRodney W. Grimes.Ql \&\en . 616afe61c15SRodney W. Grimes.It Dv EOL 617afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 618afe61c15SRodney W. Grimes.Dv ICANON 619b5e7e999SRuslan Ermilovflag is set. 620b5e7e999SRuslan ErmilovIs an additional line delimiter, like 621afe61c15SRodney W. Grimes.Dv NL . 622afe61c15SRodney W. Grimes.It Dv SUSP 623afe61c15SRodney W. GrimesIf the 624afe61c15SRodney W. Grimes.Dv ISIG 625afe61c15SRodney W. Grimesflag is enabled, receipt of the 626afe61c15SRodney W. Grimes.Dv SUSP 627afe61c15SRodney W. Grimescharacter causes a 628afe61c15SRodney W. Grimes.Dv SIGTSTP 629afe61c15SRodney W. Grimessignal to be sent to all processes in the 630afe61c15SRodney W. Grimesforeground process group for which the terminal is the 631afe61c15SRodney W. Grimescontrolling terminal, and the 632afe61c15SRodney W. Grimes.Dv SUSP 633afe61c15SRodney W. Grimescharacter is 634afe61c15SRodney W. Grimesdiscarded when processed. 635afe61c15SRodney W. Grimes.It Dv STOP 636afe61c15SRodney W. GrimesSpecial character on both input and output and is 637afe61c15SRodney W. Grimesrecognized if the 638afe61c15SRodney W. Grimes.Dv IXON 639afe61c15SRodney W. Grimes(output control) or 640afe61c15SRodney W. Grimes.Dv IXOFF 641afe61c15SRodney W. Grimes(input 642b5e7e999SRuslan Ermilovcontrol) flag is set. 643b5e7e999SRuslan ErmilovCan be used to temporarily suspend output. 644b5e7e999SRuslan ErmilovIt is useful with fast terminals to 645afe61c15SRodney W. Grimesprevent output from disappearing before it can be read. 646afe61c15SRodney W. GrimesIf 647afe61c15SRodney W. Grimes.Dv IXON 648afe61c15SRodney W. Grimesis set, the 649afe61c15SRodney W. Grimes.Dv STOP 650afe61c15SRodney W. Grimescharacter is discarded when 651afe61c15SRodney W. Grimesprocessed. 652afe61c15SRodney W. Grimes.It Dv START 653afe61c15SRodney W. GrimesSpecial character on both input and output and is 654afe61c15SRodney W. Grimesrecognized if the 655afe61c15SRodney W. Grimes.Dv IXON 656afe61c15SRodney W. Grimes(output control) or 657afe61c15SRodney W. Grimes.Dv IXOFF 658afe61c15SRodney W. Grimes(input 659b5e7e999SRuslan Ermilovcontrol) flag is set. 660b5e7e999SRuslan ErmilovCan be used to resume output that has been suspended by a 661afe61c15SRodney W. Grimes.Dv STOP 6625203edcdSRuslan Ermilovcharacter. 6635203edcdSRuslan ErmilovIf 664afe61c15SRodney W. Grimes.Dv IXON 665afe61c15SRodney W. Grimesis set, the 666afe61c15SRodney W. Grimes.Dv START 667afe61c15SRodney W. Grimescharacter is discarded when processed. 668081cb6b3SMark Ovens.It Dv CR 669afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 670afe61c15SRodney W. Grimes.Dv ICANON 671afe61c15SRodney W. Grimesflag is set; it is the 672afe61c15SRodney W. Grimes.Ql \&\er , 673afe61c15SRodney W. Grimesas denoted in the 674afe61c15SRodney W. Grimes.Tn \&C 675b5e7e999SRuslan ErmilovStandard {2}. 676b5e7e999SRuslan ErmilovWhen 677afe61c15SRodney W. Grimes.Dv ICANON 678afe61c15SRodney W. Grimesand 679afe61c15SRodney W. Grimes.Dv ICRNL 680afe61c15SRodney W. Grimesare set and 681afe61c15SRodney W. Grimes.Dv IGNCR 682afe61c15SRodney W. Grimesis not set, this character is translated into a 683afe61c15SRodney W. Grimes.Dv NL , 684afe61c15SRodney W. Grimesand 685afe61c15SRodney W. Grimeshas the same effect as a 686afe61c15SRodney W. Grimes.Dv NL 687afe61c15SRodney W. Grimescharacter. 688afe61c15SRodney W. Grimes.El 689afe61c15SRodney W. Grimes.Pp 690afe61c15SRodney W. GrimesThe following special characters are extensions defined by this 691c3939fb3SRuslan Ermilovsystem and are not a part of 692c3939fb3SRuslan Ermilov.St -p1003.1 693c3939fb3SRuslan Ermilovtermios. 694afe61c15SRodney W. Grimes.Bl -tag -width indent 695afe61c15SRodney W. Grimes.It Dv EOL2 696afe61c15SRodney W. GrimesSecondary 697afe61c15SRodney W. Grimes.Dv EOL 6985203edcdSRuslan Ermilovcharacter. 6995203edcdSRuslan ErmilovSame function as 700afe61c15SRodney W. Grimes.Dv EOL . 701afe61c15SRodney W. Grimes.It Dv WERASE 702afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 703afe61c15SRodney W. Grimes.Dv ICANON 704b5e7e999SRuslan Ermilovflag is set. 705b5e7e999SRuslan ErmilovErases the last word in the current line according to one of two algorithms. 706b5e7e999SRuslan ErmilovIf the 707afe61c15SRodney W. Grimes.Dv ALTWERASE 708afe61c15SRodney W. Grimesflag is not set, first any preceding whitespace is 709afe61c15SRodney W. Grimeserased, and then the maximal sequence of non-whitespace 710b5e7e999SRuslan Ermilovcharacters. 711b5e7e999SRuslan ErmilovIf 712afe61c15SRodney W. Grimes.Dv ALTWERASE 713afe61c15SRodney W. Grimesis set, first any preceding 714afe61c15SRodney W. Grimeswhitespace is erased, and then the maximal sequence 715afe61c15SRodney W. Grimesof alphabetic/underscores or non alphabetic/underscores. 716afe61c15SRodney W. GrimesAs a special case in this second algorithm, the first previous 717afe61c15SRodney W. Grimesnon-whitespace character is skipped in determining 718afe61c15SRodney W. Grimeswhether the preceding word is a sequence of 719b5e7e999SRuslan Ermilovalphabetic/underscores. 720b5e7e999SRuslan ErmilovThis sounds confusing but turns out to be quite practical. 721afe61c15SRodney W. Grimes.It Dv REPRINT 722afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 723afe61c15SRodney W. Grimes.Dv ICANON 724b5e7e999SRuslan Ermilovflag is set. 725b5e7e999SRuslan ErmilovCauses the current input edit line to be retyped. 726afe61c15SRodney W. Grimes.It Dv DSUSP 727afe61c15SRodney W. GrimesHas similar actions to the 728afe61c15SRodney W. Grimes.Dv SUSP 729afe61c15SRodney W. Grimescharacter, except that 730afe61c15SRodney W. Grimesthe 731afe61c15SRodney W. Grimes.Dv SIGTSTP 732afe61c15SRodney W. Grimessignal is delivered when one of the processes 733edf0e5b3SMike Pritchardin the foreground process group issues a 734edf0e5b3SMike Pritchard.Fn read 735edf0e5b3SMike Pritchardto the 736afe61c15SRodney W. Grimescontrolling terminal. 737afe61c15SRodney W. Grimes.It Dv LNEXT 738afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 739afe61c15SRodney W. Grimes.Dv IEXTEN 740b5e7e999SRuslan Ermilovflag is set. 741b5e7e999SRuslan ErmilovReceipt of this character causes the next character to be taken literally. 742afe61c15SRodney W. Grimes.It Dv DISCARD 743afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 744afe61c15SRodney W. Grimes.Dv IEXTEN 745b5e7e999SRuslan Ermilovflag is set. 746b5e7e999SRuslan ErmilovReceipt of this character toggles the flushing of terminal output. 747afe61c15SRodney W. Grimes.It Dv STATUS 748afe61c15SRodney W. GrimesSpecial character on input and is recognized if the 749afe61c15SRodney W. Grimes.Dv ICANON 750b5e7e999SRuslan Ermilovflag is set. 751b5e7e999SRuslan ErmilovReceipt of this character causes a 752afe61c15SRodney W. Grimes.Dv SIGINFO 753afe61c15SRodney W. Grimessignal to be sent to the foreground process group of the 754b5e7e999SRuslan Ermilovterminal. 755b5e7e999SRuslan ErmilovAlso, if the 756afe61c15SRodney W. Grimes.Dv NOKERNINFO 757afe61c15SRodney W. Grimesflag is not set, it 758afe61c15SRodney W. Grimescauses the kernel to write a status message to the terminal 759afe61c15SRodney W. Grimesthat displays the current load average, the name of the 760afe61c15SRodney W. Grimescommand in the foreground, its process ID, the symbolic 761afe61c15SRodney W. Grimeswait channel, the number of user and system seconds used, 762afe61c15SRodney W. Grimesthe percentage of cpu the process is getting, and the resident 763afe61c15SRodney W. Grimesset size of the process. 764*2dcf8c45SMichael Gmelin.Pp 765*2dcf8c45SMichael GmelinIn case the 766*2dcf8c45SMichael Gmelin.Xr sysctl 8 767*2dcf8c45SMichael Gmelinvariable 768*2dcf8c45SMichael Gmelin.Va kern.tty_info_kstacks 769*2dcf8c45SMichael Gmelinis set to a non-zero value, the running thread's stack is 770*2dcf8c45SMichael Gmelinwritten to the terminal (e.g., for debugging purposes). 771afe61c15SRodney W. Grimes.El 772afe61c15SRodney W. Grimes.Pp 773afe61c15SRodney W. GrimesThe 774afe61c15SRodney W. Grimes.Dv NL 775afe61c15SRodney W. Grimesand 776afe61c15SRodney W. Grimes.Dv CR 777afe61c15SRodney W. Grimescharacters cannot be changed. 778afe61c15SRodney W. GrimesThe values for all the remaining characters can be set and are 779afe61c15SRodney W. Grimesdescribed later in the document under 780afe61c15SRodney W. GrimesSpecial Control Characters. 781afe61c15SRodney W. Grimes.Pp 782afe61c15SRodney W. GrimesSpecial 783afe61c15SRodney W. Grimescharacter functions associated with changeable special control characters 784afe61c15SRodney W. Grimescan be disabled individually by setting their value to 785afe61c15SRodney W. Grimes.Dv {_POSIX_VDISABLE} ; 786afe61c15SRodney W. Grimessee 787afe61c15SRodney W. Grimes.Sx "Special Control Characters" . 788afe61c15SRodney W. Grimes.Pp 789afe61c15SRodney W. GrimesIf two or more special characters have the same value, the function 790afe61c15SRodney W. Grimesperformed when that character is received is undefined. 791afe61c15SRodney W. Grimes.Ss Modem Disconnect 792afe61c15SRodney W. GrimesIf a modem disconnect is detected by the terminal interface for a 793afe61c15SRodney W. Grimescontrolling terminal, and if 794afe61c15SRodney W. Grimes.Dv CLOCAL 795afe61c15SRodney W. Grimesis not set in the 796afe61c15SRodney W. Grimes.Fa c_cflag 797afe61c15SRodney W. Grimesfield for 798afe61c15SRodney W. Grimesthe terminal, the 799afe61c15SRodney W. Grimes.Dv SIGHUP 800afe61c15SRodney W. Grimessignal is sent to the controlling 801b5e7e999SRuslan Ermilovprocess associated with the terminal. 802b5e7e999SRuslan ErmilovUnless other arrangements have 803afe61c15SRodney W. Grimesbeen made, this causes the controlling process to terminate. 804edf0e5b3SMike PritchardAny subsequent call to the 805edf0e5b3SMike Pritchard.Fn read 806edf0e5b3SMike Pritchardfunction returns the value zero, 807b5e7e999SRuslan Ermilovindicating end of file. 808b5e7e999SRuslan ErmilovThus, processes that read a terminal 809afe61c15SRodney W. Grimesfile and test for end-of-file can terminate appropriately after a 810afe61c15SRodney W. Grimesdisconnect. 811afe61c15SRodney W. Grimes.\" If the 812afe61c15SRodney W. Grimes.\" .Er EIO 813afe61c15SRodney W. Grimes.\" condition specified in 6.1.1.4 that applies 814afe61c15SRodney W. Grimes.\" when the implementation supports job control also exists, it is 815afe61c15SRodney W. Grimes.\" unspecified whether the 816afe61c15SRodney W. Grimes.\" .Dv EOF 817afe61c15SRodney W. Grimes.\" condition or the 818afe61c15SRodney W. Grimes.\" .Pf [ Dv EIO 819afe61c15SRodney W. Grimes.\" ] is returned. 820afe61c15SRodney W. GrimesAny 821edf0e5b3SMike Pritchardsubsequent 822edf0e5b3SMike Pritchard.Fn write 823edf0e5b3SMike Pritchardto the terminal device returns -1, with 824afe61c15SRodney W. Grimes.Va errno 825afe61c15SRodney W. Grimesset to 826afe61c15SRodney W. Grimes.Er EIO , 827afe61c15SRodney W. Grimesuntil the device is closed. 828afe61c15SRodney W. Grimes.Sh General Terminal Interface 829afe61c15SRodney W. Grimes.Ss Closing a Terminal Device File 830afe61c15SRodney W. GrimesThe last process to close a terminal device file causes any output 831b5e7e999SRuslan Ermilovto be sent to the device and any input to be discarded. 832b5e7e999SRuslan ErmilovThen, if 833afe61c15SRodney W. Grimes.Dv HUPCL 834afe61c15SRodney W. Grimesis set in the control modes, and the communications port supports a 835afe61c15SRodney W. Grimesdisconnect function, the terminal device performs a disconnect. 836afe61c15SRodney W. Grimes.Ss Parameters That Can Be Set 837afe61c15SRodney W. GrimesRoutines that need to control certain terminal 838afe61c15SRodney W. Grimes.Tn I/O 839afe61c15SRodney W. Grimescharacteristics 840afe61c15SRodney W. Grimesdo so by using the termios structure as defined in the header 841fe08efe6SRuslan Ermilov.In termios.h . 842afe61c15SRodney W. GrimesThis structure contains minimally four scalar elements of bit flags 843b5e7e999SRuslan Ermilovand one array of special characters. 844b5e7e999SRuslan ErmilovThe scalar flag elements are named: 845afe61c15SRodney W. Grimes.Fa c_iflag , 846afe61c15SRodney W. Grimes.Fa c_oflag , 847afe61c15SRodney W. Grimes.Fa c_cflag , 848afe61c15SRodney W. Grimesand 849afe61c15SRodney W. Grimes.Fa c_lflag . 850afe61c15SRodney W. GrimesThe character array is named 851afe61c15SRodney W. Grimes.Fa c_cc , 852afe61c15SRodney W. Grimesand its maximum index is 853afe61c15SRodney W. Grimes.Dv NCCS . 854afe61c15SRodney W. Grimes.Ss Input Modes 855afe61c15SRodney W. GrimesValues of the 856afe61c15SRodney W. Grimes.Fa c_iflag 857afe61c15SRodney W. Grimesfield describe the basic 858afe61c15SRodney W. Grimesterminal input control, and are composed of 859afe61c15SRodney W. Grimesfollowing masks: 860afe61c15SRodney W. Grimes.Pp 861afe61c15SRodney W. Grimes.Bl -tag -width IMAXBEL -offset indent -compact 862afe61c15SRodney W. Grimes.It Dv IGNBRK 863afe61c15SRodney W. Grimes/* ignore BREAK condition */ 864afe61c15SRodney W. Grimes.It Dv BRKINT 865afe61c15SRodney W. Grimes/* map BREAK to SIGINTR */ 866afe61c15SRodney W. Grimes.It Dv IGNPAR 867afe61c15SRodney W. Grimes/* ignore (discard) parity errors */ 868afe61c15SRodney W. Grimes.It Dv PARMRK 869afe61c15SRodney W. Grimes/* mark parity and framing errors */ 870afe61c15SRodney W. Grimes.It Dv INPCK 871afe61c15SRodney W. Grimes/* enable checking of parity errors */ 872afe61c15SRodney W. Grimes.It Dv ISTRIP 873afe61c15SRodney W. Grimes/* strip 8th bit off chars */ 874afe61c15SRodney W. Grimes.It Dv INLCR 875afe61c15SRodney W. Grimes/* map NL into CR */ 876afe61c15SRodney W. Grimes.It Dv IGNCR 877afe61c15SRodney W. Grimes/* ignore CR */ 878afe61c15SRodney W. Grimes.It Dv ICRNL 879afe61c15SRodney W. Grimes/* map CR to NL (ala CRMOD) */ 880afe61c15SRodney W. Grimes.It Dv IXON 881afe61c15SRodney W. Grimes/* enable output flow control */ 882afe61c15SRodney W. Grimes.It Dv IXOFF 883afe61c15SRodney W. Grimes/* enable input flow control */ 884afe61c15SRodney W. Grimes.It Dv IXANY 885afe61c15SRodney W. Grimes/* any char will restart after stop */ 886afe61c15SRodney W. Grimes.It Dv IMAXBEL 887afe61c15SRodney W. Grimes/* ring bell on input queue full */ 888afe61c15SRodney W. Grimes.El 889afe61c15SRodney W. Grimes.Pp 890afe61c15SRodney W. GrimesIn the context of asynchronous serial data transmission, a break 891afe61c15SRodney W. Grimescondition is defined as a sequence of zero-valued bits that continues for 892b5e7e999SRuslan Ermilovmore than the time to send one byte. 893b5e7e999SRuslan ErmilovThe entire sequence of zero-valued 894afe61c15SRodney W. Grimesbits is interpreted as a single break condition, even if it continues for 895b5e7e999SRuslan Ermilova time equivalent to more than one byte. 896b5e7e999SRuslan ErmilovIn contexts other than 897afe61c15SRodney W. Grimesasynchronous serial data transmission the definition of a break condition 898afe61c15SRodney W. Grimesis implementation defined. 899afe61c15SRodney W. Grimes.Pp 900afe61c15SRodney W. GrimesIf 901afe61c15SRodney W. Grimes.Dv IGNBRK 902afe61c15SRodney W. Grimesis set, a break condition detected on input is ignored, that 903b5e7e999SRuslan Ermilovis, not put on the input queue and therefore not read by any process. 904b5e7e999SRuslan ErmilovIf 905afe61c15SRodney W. Grimes.Dv IGNBRK 906afe61c15SRodney W. Grimesis not set and 907afe61c15SRodney W. Grimes.Dv BRKINT 908afe61c15SRodney W. Grimesis set, the break condition flushes the 909afe61c15SRodney W. Grimesinput and output queues and if the terminal is the controlling terminal 910afe61c15SRodney W. Grimesof a foreground process group, the break condition generates a 911afe61c15SRodney W. Grimessingle 912afe61c15SRodney W. Grimes.Dv SIGINT 913b5e7e999SRuslan Ermilovsignal to that foreground process group. 914b5e7e999SRuslan ErmilovIf neither 915afe61c15SRodney W. Grimes.Dv IGNBRK 916afe61c15SRodney W. Grimesnor 917afe61c15SRodney W. Grimes.Dv BRKINT 918afe61c15SRodney W. Grimesis set, a break condition is read as a single 919afe61c15SRodney W. Grimes.Ql \&\e0 , 920afe61c15SRodney W. Grimesor if 921afe61c15SRodney W. Grimes.Dv PARMRK 922afe61c15SRodney W. Grimesis set, as 923afe61c15SRodney W. Grimes.Ql \&\e377 , 924afe61c15SRodney W. Grimes.Ql \&\e0 , 925afe61c15SRodney W. Grimes.Ql \&\e0 . 926afe61c15SRodney W. Grimes.Pp 927afe61c15SRodney W. GrimesIf 928afe61c15SRodney W. Grimes.Dv IGNPAR 929afe61c15SRodney W. Grimesis set, a byte with a framing or parity error (other than 930afe61c15SRodney W. Grimesbreak) is ignored. 931afe61c15SRodney W. Grimes.Pp 932afe61c15SRodney W. GrimesIf 933afe61c15SRodney W. Grimes.Dv PARMRK 934afe61c15SRodney W. Grimesis set, and 935afe61c15SRodney W. Grimes.Dv IGNPAR 936afe61c15SRodney W. Grimesis not set, a byte with a framing or parity 937afe61c15SRodney W. Grimeserror (other than break) is given to the application as the 938afe61c15SRodney W. Grimesthree-character sequence 939afe61c15SRodney W. Grimes.Ql \&\e377 , 940afe61c15SRodney W. Grimes.Ql \&\e0 , 941afe61c15SRodney W. GrimesX, where 942afe61c15SRodney W. Grimes.Ql \&\e377 , 943afe61c15SRodney W. Grimes.Ql \&\e0 944afe61c15SRodney W. Grimesis a two-character 945afe61c15SRodney W. Grimesflag preceding each sequence and X is the data of the character received 9465203edcdSRuslan Ermilovin error. 9475203edcdSRuslan ErmilovTo avoid ambiguity in this case, if 948afe61c15SRodney W. Grimes.Dv ISTRIP 949afe61c15SRodney W. Grimesis not set, a valid 950afe61c15SRodney W. Grimescharacter of 951afe61c15SRodney W. Grimes.Ql \&\e377 952afe61c15SRodney W. Grimesis given to the application as 953afe61c15SRodney W. Grimes.Ql \&\e377 , 954afe61c15SRodney W. Grimes.Ql \&\e377 . 955afe61c15SRodney W. GrimesIf 956afe61c15SRodney W. Grimesneither 957afe61c15SRodney W. Grimes.Dv PARMRK 958afe61c15SRodney W. Grimesnor 959afe61c15SRodney W. Grimes.Dv IGNPAR 960afe61c15SRodney W. Grimesis set, a framing or parity error (other than 961afe61c15SRodney W. Grimesbreak) is given to the application as a single character 962afe61c15SRodney W. Grimes.Ql \&\e0 . 963afe61c15SRodney W. Grimes.Pp 964afe61c15SRodney W. GrimesIf 965afe61c15SRodney W. Grimes.Dv INPCK 966b5e7e999SRuslan Ermilovis set, input parity checking is enabled. 967b5e7e999SRuslan ErmilovIf 968afe61c15SRodney W. Grimes.Dv INPCK 969afe61c15SRodney W. Grimesis not set, 970afe61c15SRodney W. Grimesinput parity checking is disabled, allowing output parity generation 971b5e7e999SRuslan Ermilovwithout input parity errors. 972b5e7e999SRuslan ErmilovNote that whether input parity checking is 973afe61c15SRodney W. Grimesenabled or disabled is independent of whether parity detection is enabled 974afe61c15SRodney W. Grimesor disabled (see 975afe61c15SRodney W. Grimes.Sx "Control Modes" ) . 976afe61c15SRodney W. GrimesIf parity detection is enabled but input 977afe61c15SRodney W. Grimesparity checking is disabled, the hardware to which the terminal is 978afe61c15SRodney W. Grimesconnected recognizes the parity bit, but the terminal special file 979afe61c15SRodney W. Grimesdoes not check whether this bit is set correctly or not. 980afe61c15SRodney W. Grimes.Pp 981afe61c15SRodney W. GrimesIf 982afe61c15SRodney W. Grimes.Dv ISTRIP 983afe61c15SRodney W. Grimesis set, valid input bytes are first stripped to seven bits, 984afe61c15SRodney W. Grimesotherwise all eight bits are processed. 985afe61c15SRodney W. Grimes.Pp 986afe61c15SRodney W. GrimesIf 987afe61c15SRodney W. Grimes.Dv INLCR 988afe61c15SRodney W. Grimesis set, a received 989afe61c15SRodney W. Grimes.Dv NL 990afe61c15SRodney W. Grimescharacter is translated into a 991afe61c15SRodney W. Grimes.Dv CR 9925203edcdSRuslan Ermilovcharacter. 9935203edcdSRuslan ErmilovIf 994afe61c15SRodney W. Grimes.Dv IGNCR 995afe61c15SRodney W. Grimesis set, a received 996afe61c15SRodney W. Grimes.Dv CR 997afe61c15SRodney W. Grimescharacter is ignored (not 9985203edcdSRuslan Ermilovread). 9995203edcdSRuslan ErmilovIf 1000afe61c15SRodney W. Grimes.Dv IGNCR 1001afe61c15SRodney W. Grimesis not set and 1002afe61c15SRodney W. Grimes.Dv ICRNL 1003afe61c15SRodney W. Grimesis set, a received 1004afe61c15SRodney W. Grimes.Dv CR 1005afe61c15SRodney W. Grimescharacter is 1006afe61c15SRodney W. Grimestranslated into a 1007afe61c15SRodney W. Grimes.Dv NL 1008afe61c15SRodney W. Grimescharacter. 1009afe61c15SRodney W. Grimes.Pp 1010afe61c15SRodney W. GrimesIf 1011afe61c15SRodney W. Grimes.Dv IXON 1012b5e7e999SRuslan Ermilovis set, start/stop output control is enabled. 1013b5e7e999SRuslan ErmilovA received 1014afe61c15SRodney W. Grimes.Dv STOP 1015afe61c15SRodney W. Grimescharacter suspends output and a received 1016afe61c15SRodney W. Grimes.Dv START 1017afe61c15SRodney W. Grimescharacter 10186d249eeeSSheldon Hearnrestarts output. 10196d249eeeSSheldon HearnIf 1020afe61c15SRodney W. Grimes.Dv IXANY 1021afe61c15SRodney W. Grimesis also set, then any character may 10226d249eeeSSheldon Hearnrestart output. 10236d249eeeSSheldon HearnWhen 1024afe61c15SRodney W. Grimes.Dv IXON 1025afe61c15SRodney W. Grimesis set, 1026afe61c15SRodney W. Grimes.Dv START 1027afe61c15SRodney W. Grimesand 1028afe61c15SRodney W. Grimes.Dv STOP 1029afe61c15SRodney W. Grimescharacters are not 1030b5e7e999SRuslan Ermilovread, but merely perform flow control functions. 1031b5e7e999SRuslan ErmilovWhen 1032afe61c15SRodney W. Grimes.Dv IXON 1033afe61c15SRodney W. Grimesis not set, 1034afe61c15SRodney W. Grimesthe 1035afe61c15SRodney W. Grimes.Dv START 1036afe61c15SRodney W. Grimesand 1037afe61c15SRodney W. Grimes.Dv STOP 1038afe61c15SRodney W. Grimescharacters are read. 1039afe61c15SRodney W. Grimes.Pp 1040afe61c15SRodney W. GrimesIf 1041afe61c15SRodney W. Grimes.Dv IXOFF 1042b5e7e999SRuslan Ermilovis set, start/stop input control is enabled. 1043b5e7e999SRuslan ErmilovThe system shall transmit one or more 1044afe61c15SRodney W. Grimes.Dv STOP 1045afe61c15SRodney W. Grimescharacters, which are intended to cause the 1046afe61c15SRodney W. Grimesterminal device to stop transmitting data, as needed to prevent the input 1047afe61c15SRodney W. Grimesqueue from overflowing and causing the undefined behavior described in 1048afe61c15SRodney W. Grimes.Sx "Input Processing and Reading Data" , 1049afe61c15SRodney W. Grimesand shall transmit one or more 1050afe61c15SRodney W. Grimes.Dv START 1051afe61c15SRodney W. Grimescharacters, which are 1052afe61c15SRodney W. Grimesintended to cause the terminal device to resume transmitting data, as 1053afe61c15SRodney W. Grimessoon as the device can continue transmitting data without risk of 1054b5e7e999SRuslan Ermilovoverflowing the input queue. 1055b5e7e999SRuslan ErmilovThe precise conditions under which 1056afe61c15SRodney W. Grimes.Dv STOP 1057afe61c15SRodney W. Grimesand 1058c2025a76SJoel Dahl.Dv START 1059afe61c15SRodney W. Grimescharacters are transmitted are implementation defined. 1060afe61c15SRodney W. Grimes.Pp 1061afe61c15SRodney W. GrimesIf 1062afe61c15SRodney W. Grimes.Dv IMAXBEL 1063afe61c15SRodney W. Grimesis set and the input queue is full, subsequent input shall cause an 1064afe61c15SRodney W. Grimes.Tn ASCII 1065afe61c15SRodney W. Grimes.Dv BEL 106643d1df33SAlexander Langercharacter to be transmitted to 1067afe61c15SRodney W. Grimesthe output queue. 1068afe61c15SRodney W. Grimes.Pp 1069edf0e5b3SMike PritchardThe initial input control value after 1070edf0e5b3SMike Pritchard.Fn open 1071edf0e5b3SMike Pritchardis implementation defined. 1072afe61c15SRodney W. Grimes.Ss Output Modes 1073afe61c15SRodney W. GrimesValues of the 1074afe61c15SRodney W. Grimes.Fa c_oflag 1075afe61c15SRodney W. Grimesfield describe the basic terminal output control, 1076afe61c15SRodney W. Grimesand are composed of the following masks: 1077afe61c15SRodney W. Grimes.Pp 1078bc093719SEd Schouten.Bl -tag -width ONOEOT -offset indent -compact 1079afe61c15SRodney W. Grimes.It Dv OPOST 1080afe61c15SRodney W. Grimes/* enable following output processing */ 1081afe61c15SRodney W. Grimes.It Dv ONLCR 1082afe61c15SRodney W. Grimes/* map NL to CR-NL (ala 1083afe61c15SRodney W. Grimes.Dv CRMOD ) 1084afe61c15SRodney W. Grimes*/ 10853617ddfcSAssar Westerlund.It Dv OCRNL 10863617ddfcSAssar Westerlund/* map CR to NL */ 1087bc093719SEd Schouten.It Dv TABDLY 1088bc093719SEd Schouten/* tab delay mask */ 1089bc093719SEd Schouten.It Dv TAB0 1090bc093719SEd Schouten/* no tab delay and expansion */ 1091bc093719SEd Schouten.It Dv TAB3 1092afe61c15SRodney W. Grimes/* expand tabs to spaces */ 1093afe61c15SRodney W. Grimes.It Dv ONOEOT 1094afe61c15SRodney W. Grimes/* discard 1095afe61c15SRodney W. Grimes.Dv EOT Ns 's 1096afe61c15SRodney W. Grimes.Ql \&^D 1097afe61c15SRodney W. Grimeson output) */ 10983617ddfcSAssar Westerlund.It Dv ONOCR 10993617ddfcSAssar Westerlund/* do not transmit CRs on column 0 */ 11003617ddfcSAssar Westerlund.It Dv ONLRET 1101f87717faSMike Pritchard/* on the terminal NL performs the CR function */ 1102afe61c15SRodney W. Grimes.El 1103afe61c15SRodney W. Grimes.Pp 1104afe61c15SRodney W. GrimesIf 1105afe61c15SRodney W. Grimes.Dv OPOST 1106afe61c15SRodney W. Grimesis set, the remaining flag masks are interpreted as follows; 1107afe61c15SRodney W. Grimesotherwise characters are transmitted without change. 1108afe61c15SRodney W. Grimes.Pp 1109afe61c15SRodney W. GrimesIf 1110afe61c15SRodney W. Grimes.Dv ONLCR 1111afe61c15SRodney W. Grimesis set, newlines are translated to carriage return, linefeeds. 1112afe61c15SRodney W. Grimes.Pp 1113afe61c15SRodney W. GrimesIf 11143617ddfcSAssar Westerlund.Dv OCRNL 11153617ddfcSAssar Westerlundis set, carriage returns are translated to newlines. 11163617ddfcSAssar Westerlund.Pp 1117bc093719SEd SchoutenThe 1118bc093719SEd Schouten.Dv TABDLY 1119bc093719SEd Schoutenbits specify the tab delay. 1120bc093719SEd SchoutenThe 1121bc093719SEd Schouten.Fa c_oflag 1122bc093719SEd Schoutenis masked with 1123bc093719SEd Schouten.Dv TABDLY 1124bc093719SEd Schoutenand compared with the 1125bc093719SEd Schoutenvalues 1126bc093719SEd Schouten.Dv TAB0 1127bc093719SEd Schoutenor 1128bc093719SEd Schouten.Dv TAB3 . 11293617ddfcSAssar WesterlundIf 1130bc093719SEd Schouten.Dv TAB3 1131afe61c15SRodney W. Grimesis set, tabs are expanded to the appropriate number of 1132afe61c15SRodney W. Grimesspaces (assuming 8 column tab stops). 1133afe61c15SRodney W. Grimes.Pp 1134afe61c15SRodney W. GrimesIf 1135afe61c15SRodney W. Grimes.Dv ONOEOT 1136afe61c15SRodney W. Grimesis set, 1137afe61c15SRodney W. Grimes.Tn ASCII 113868161b6bSRuslan Ermilov.Dv EOT Ns 's 1139afe61c15SRodney W. Grimesare discarded on output. 11403617ddfcSAssar Westerlund.Pp 11413617ddfcSAssar WesterlundIf 11423617ddfcSAssar Westerlund.Dv ONOCR 11433617ddfcSAssar Westerlundis set, no CR character is transmitted when at column 0 (first position). 11443617ddfcSAssar Westerlund.Pp 11453617ddfcSAssar WesterlundIf 11463617ddfcSAssar Westerlund.Dv ONLRET 11473617ddfcSAssar Westerlundis set, the NL character is assumed to do the carriage-return function; 11483617ddfcSAssar Westerlundthe column pointer will be set to 0. 1149afe61c15SRodney W. Grimes.Ss Control Modes 1150afe61c15SRodney W. GrimesValues of the 1151afe61c15SRodney W. Grimes.Fa c_cflag 1152afe61c15SRodney W. Grimesfield describe the basic 1153afe61c15SRodney W. Grimesterminal hardware control, and are composed of the 1154afe61c15SRodney W. Grimesfollowing masks. 1155afe61c15SRodney W. GrimesNot all values 1156afe61c15SRodney W. Grimesspecified are supported by all hardware. 1157afe61c15SRodney W. Grimes.Pp 1158afe61c15SRodney W. Grimes.Bl -tag -width CRTSXIFLOW -offset indent -compact 1159afe61c15SRodney W. Grimes.It Dv CSIZE 1160afe61c15SRodney W. Grimes/* character size mask */ 1161afe61c15SRodney W. Grimes.It Dv CS5 1162afe61c15SRodney W. Grimes/* 5 bits (pseudo) */ 1163afe61c15SRodney W. Grimes.It Dv CS6 1164afe61c15SRodney W. Grimes/* 6 bits */ 1165afe61c15SRodney W. Grimes.It Dv CS7 1166afe61c15SRodney W. Grimes/* 7 bits */ 1167afe61c15SRodney W. Grimes.It Dv CS8 1168afe61c15SRodney W. Grimes/* 8 bits */ 1169afe61c15SRodney W. Grimes.It Dv CSTOPB 1170afe61c15SRodney W. Grimes/* send 2 stop bits */ 1171afe61c15SRodney W. Grimes.It Dv CREAD 1172afe61c15SRodney W. Grimes/* enable receiver */ 1173afe61c15SRodney W. Grimes.It Dv PARENB 1174afe61c15SRodney W. Grimes/* parity enable */ 1175afe61c15SRodney W. Grimes.It Dv PARODD 1176afe61c15SRodney W. Grimes/* odd parity, else even */ 1177afe61c15SRodney W. Grimes.It Dv HUPCL 1178afe61c15SRodney W. Grimes/* hang up on last close */ 1179afe61c15SRodney W. Grimes.It Dv CLOCAL 1180afe61c15SRodney W. Grimes/* ignore modem status lines */ 1181afe61c15SRodney W. Grimes.It Dv CCTS_OFLOW 1182afe61c15SRodney W. Grimes/* 1183afe61c15SRodney W. Grimes.Dv CTS 1184afe61c15SRodney W. Grimesflow control of output */ 1185afe61c15SRodney W. Grimes.It Dv CRTSCTS 1186afe61c15SRodney W. Grimes/* same as 1187afe61c15SRodney W. Grimes.Dv CCTS_OFLOW 1188afe61c15SRodney W. Grimes*/ 1189afe61c15SRodney W. Grimes.It Dv CRTS_IFLOW 1190afe61c15SRodney W. Grimes/* RTS flow control of input */ 1191afe61c15SRodney W. Grimes.It Dv MDMBUF 1192afe61c15SRodney W. Grimes/* flow control output via Carrier */ 1193705aad98SStephen Hurd.It Dv CNO_RTSDTR 1194705aad98SStephen Hurd/* Do not assert RTS or DTR automatically */ 1195afe61c15SRodney W. Grimes.El 1196afe61c15SRodney W. Grimes.Pp 1197afe61c15SRodney W. GrimesThe 1198afe61c15SRodney W. Grimes.Dv CSIZE 1199afe61c15SRodney W. Grimesbits specify the byte size in bits for both transmission and 1200b5e7e999SRuslan Ermilovreception. 1201b5e7e999SRuslan ErmilovThe 1202afe61c15SRodney W. Grimes.Fa c_cflag 1203afe61c15SRodney W. Grimesis masked with 1204afe61c15SRodney W. Grimes.Dv CSIZE 1205afe61c15SRodney W. Grimesand compared with the 1206afe61c15SRodney W. Grimesvalues 1207afe61c15SRodney W. Grimes.Dv CS5 , 1208afe61c15SRodney W. Grimes.Dv CS6 , 1209afe61c15SRodney W. Grimes.Dv CS7 , 1210afe61c15SRodney W. Grimesor 1211afe61c15SRodney W. Grimes.Dv CS8 . 1212b5e7e999SRuslan ErmilovThis size does not include the parity bit, if any. 1213b5e7e999SRuslan ErmilovIf 1214afe61c15SRodney W. Grimes.Dv CSTOPB 1215b5e7e999SRuslan Ermilovis set, two stop bits are used, otherwise one stop bit. 1216b5e7e999SRuslan ErmilovFor example, at 110 baud, two stop bits are normally used. 1217afe61c15SRodney W. Grimes.Pp 1218afe61c15SRodney W. GrimesIf 1219afe61c15SRodney W. Grimes.Dv CREAD 1220b5e7e999SRuslan Ermilovis set, the receiver is enabled. 1221b5e7e999SRuslan ErmilovOtherwise, no character is received. 1222b5e7e999SRuslan ErmilovNot all hardware supports this bit. 1223b5e7e999SRuslan ErmilovIn fact, this flag is pretty silly and if it were not part of the 12244b66483fSRuslan Ermilov.Nm 1225afe61c15SRodney W. Grimesspecification 1226afe61c15SRodney W. Grimesit would be omitted. 1227afe61c15SRodney W. Grimes.Pp 1228afe61c15SRodney W. GrimesIf 1229afe61c15SRodney W. Grimes.Dv PARENB 1230afe61c15SRodney W. Grimesis set, parity generation and detection are enabled and a parity 1231b5e7e999SRuslan Ermilovbit is added to each character. 1232b5e7e999SRuslan ErmilovIf parity is enabled, 1233afe61c15SRodney W. Grimes.Dv PARODD 1234afe61c15SRodney W. Grimesspecifies 1235afe61c15SRodney W. Grimesodd parity if set, otherwise even parity is used. 1236afe61c15SRodney W. Grimes.Pp 1237afe61c15SRodney W. GrimesIf 1238afe61c15SRodney W. Grimes.Dv HUPCL 1239afe61c15SRodney W. Grimesis set, the modem control lines for the port are lowered 1240afe61c15SRodney W. Grimeswhen the last process with the port open closes the port or the process 1241b5e7e999SRuslan Ermilovterminates. 1242b5e7e999SRuslan ErmilovThe modem connection is broken. 1243afe61c15SRodney W. Grimes.Pp 1244afe61c15SRodney W. GrimesIf 1245afe61c15SRodney W. Grimes.Dv CLOCAL 1246afe61c15SRodney W. Grimesis set, a connection does not depend on the state of the modem 1247b5e7e999SRuslan Ermilovstatus lines. 1248b5e7e999SRuslan ErmilovIf 1249afe61c15SRodney W. Grimes.Dv CLOCAL 1250afe61c15SRodney W. Grimesis clear, the modem status lines are 1251afe61c15SRodney W. Grimesmonitored. 1252afe61c15SRodney W. Grimes.Pp 1253edf0e5b3SMike PritchardUnder normal circumstances, a call to the 1254edf0e5b3SMike Pritchard.Fn open 1255edf0e5b3SMike Pritchardfunction waits for 1256b5e7e999SRuslan Ermilovthe modem connection to complete. 1257b5e7e999SRuslan ErmilovHowever, if the 1258afe61c15SRodney W. Grimes.Dv O_NONBLOCK 1259afe61c15SRodney W. Grimesflag is set 1260afe61c15SRodney W. Grimesor if 1261afe61c15SRodney W. Grimes.Dv CLOCAL 1262edf0e5b3SMike Pritchardhas been set, the 1263edf0e5b3SMike Pritchard.Fn open 1264edf0e5b3SMike Pritchardfunction returns 1265afe61c15SRodney W. Grimesimmediately without waiting for the connection. 1266afe61c15SRodney W. Grimes.Pp 1267afe61c15SRodney W. GrimesThe 1268afe61c15SRodney W. Grimes.Dv CCTS_OFLOW 1269afe61c15SRodney W. Grimes.Pf ( Dv CRTSCTS ) 1270afe61c15SRodney W. Grimesflag is currently unused. 1271afe61c15SRodney W. Grimes.Pp 1272afe61c15SRodney W. GrimesIf 1273afe61c15SRodney W. Grimes.Dv MDMBUF 1274afe61c15SRodney W. Grimesis set then output flow control is controlled by the state 1275afe61c15SRodney W. Grimesof Carrier Detect. 1276afe61c15SRodney W. Grimes.Pp 1277705aad98SStephen HurdIf 1278705aad98SStephen Hurd.Dv CNO_RTSDTR 1279705aad98SStephen Hurdis set then the RTS and DTR lines will not be asserted when the device 1280705aad98SStephen Hurdis opened. 1281705aad98SStephen HurdAs a result, this flag is only useful on initial-state devices. 1282705aad98SStephen Hurd.Pp 1283afe61c15SRodney W. GrimesIf the object for which the control modes are set is not an asynchronous 1284afe61c15SRodney W. Grimesserial connection, some of the modes may be ignored; for example, if an 1285afe61c15SRodney W. Grimesattempt is made to set the baud rate on a network connection to a 1286afe61c15SRodney W. Grimesterminal on another host, the baud rate may or may not be set on the 1287afe61c15SRodney W. Grimesconnection between that terminal and the machine it is directly connected 1288afe61c15SRodney W. Grimesto. 1289afe61c15SRodney W. Grimes.Ss Local Modes 1290afe61c15SRodney W. GrimesValues of the 1291afe61c15SRodney W. Grimes.Fa c_lflag 1292afe61c15SRodney W. Grimesfield describe the control of 1293afe61c15SRodney W. Grimesvarious functions, and are composed of the following 1294afe61c15SRodney W. Grimesmasks. 1295afe61c15SRodney W. Grimes.Pp 1296afe61c15SRodney W. Grimes.Bl -tag -width NOKERNINFO -offset indent -compact 1297afe61c15SRodney W. Grimes.It Dv ECHOKE 1298afe61c15SRodney W. Grimes/* visual erase for line kill */ 1299afe61c15SRodney W. Grimes.It Dv ECHOE 1300afe61c15SRodney W. Grimes/* visually erase chars */ 1301afe61c15SRodney W. Grimes.It Dv ECHO 1302afe61c15SRodney W. Grimes/* enable echoing */ 1303afe61c15SRodney W. Grimes.It Dv ECHONL 1304afe61c15SRodney W. Grimes/* echo 1305afe61c15SRodney W. Grimes.Dv NL 1306afe61c15SRodney W. Grimeseven if 1307afe61c15SRodney W. Grimes.Dv ECHO 1308afe61c15SRodney W. Grimesis off */ 1309afe61c15SRodney W. Grimes.It Dv ECHOPRT 1310afe61c15SRodney W. Grimes/* visual erase mode for hardcopy */ 1311afe61c15SRodney W. Grimes.It Dv ECHOCTL 1312afe61c15SRodney W. Grimes/* echo control chars as ^(Char) */ 1313afe61c15SRodney W. Grimes.It Dv ISIG 1314afe61c15SRodney W. Grimes/* enable signals 1315afe61c15SRodney W. Grimes.Dv INTR , 1316afe61c15SRodney W. Grimes.Dv QUIT , 1317afe61c15SRodney W. Grimes.Dv [D]SUSP 1318afe61c15SRodney W. Grimes*/ 1319afe61c15SRodney W. Grimes.It Dv ICANON 1320afe61c15SRodney W. Grimes/* canonicalize input lines */ 1321afe61c15SRodney W. Grimes.It Dv ALTWERASE 1322afe61c15SRodney W. Grimes/* use alternate 1323afe61c15SRodney W. Grimes.Dv WERASE 1324afe61c15SRodney W. Grimesalgorithm */ 1325afe61c15SRodney W. Grimes.It Dv IEXTEN 1326afe61c15SRodney W. Grimes/* enable 1327afe61c15SRodney W. Grimes.Dv DISCARD 1328afe61c15SRodney W. Grimesand 1329afe61c15SRodney W. Grimes.Dv LNEXT 1330afe61c15SRodney W. Grimes*/ 1331afe61c15SRodney W. Grimes.It Dv EXTPROC 1332afe61c15SRodney W. Grimes/* external processing */ 1333afe61c15SRodney W. Grimes.It Dv TOSTOP 1334afe61c15SRodney W. Grimes/* stop background jobs from output */ 1335afe61c15SRodney W. Grimes.It Dv FLUSHO 1336afe61c15SRodney W. Grimes/* output being flushed (state) */ 1337afe61c15SRodney W. Grimes.It Dv NOKERNINFO 1338afe61c15SRodney W. Grimes/* no kernel output from 1339afe61c15SRodney W. Grimes.Dv VSTATUS 1340afe61c15SRodney W. Grimes*/ 1341afe61c15SRodney W. Grimes.It Dv PENDIN 1342afe61c15SRodney W. Grimes/* XXX retype pending input (state) */ 1343afe61c15SRodney W. Grimes.It Dv NOFLSH 1344afe61c15SRodney W. Grimes/* don't flush after interrupt */ 1345afe61c15SRodney W. Grimes.El 1346afe61c15SRodney W. Grimes.Pp 1347afe61c15SRodney W. GrimesIf 1348afe61c15SRodney W. Grimes.Dv ECHO 1349b5e7e999SRuslan Ermilovis set, input characters are echoed back to the terminal. 1350b5e7e999SRuslan ErmilovIf 1351afe61c15SRodney W. Grimes.Dv ECHO 1352afe61c15SRodney W. Grimesis not set, input characters are not echoed. 1353afe61c15SRodney W. Grimes.Pp 1354afe61c15SRodney W. GrimesIf 1355afe61c15SRodney W. Grimes.Dv ECHOE 1356afe61c15SRodney W. Grimesand 1357afe61c15SRodney W. Grimes.Dv ICANON 1358afe61c15SRodney W. Grimesare set, the 1359afe61c15SRodney W. Grimes.Dv ERASE 1360afe61c15SRodney W. Grimescharacter causes the terminal 1361afe61c15SRodney W. Grimesto erase the last character in the current line from the display, if 1362b5e7e999SRuslan Ermilovpossible. 1363b5e7e999SRuslan ErmilovIf there is no character to erase, an implementation may echo 1364afe61c15SRodney W. Grimesan indication that this was the case or do nothing. 1365afe61c15SRodney W. Grimes.Pp 1366afe61c15SRodney W. GrimesIf 1367afe61c15SRodney W. Grimes.Dv ECHOK 1368afe61c15SRodney W. Grimesand 1369afe61c15SRodney W. Grimes.Dv ICANON 1370afe61c15SRodney W. Grimesare set, the 1371afe61c15SRodney W. Grimes.Dv KILL 1372afe61c15SRodney W. Grimescharacter causes 1373afe61c15SRodney W. Grimesthe current line to be discarded and the system echoes the 1374afe61c15SRodney W. Grimes.Ql \&\en 1375afe61c15SRodney W. Grimescharacter after the 1376afe61c15SRodney W. Grimes.Dv KILL 1377afe61c15SRodney W. Grimescharacter. 1378afe61c15SRodney W. Grimes.Pp 1379afe61c15SRodney W. GrimesIf 1380afe61c15SRodney W. Grimes.Dv ECHOKE 1381afe61c15SRodney W. Grimesand 1382afe61c15SRodney W. Grimes.Dv ICANON 1383afe61c15SRodney W. Grimesare set, the 1384afe61c15SRodney W. Grimes.Dv KILL 1385afe61c15SRodney W. Grimescharacter causes 1386afe61c15SRodney W. Grimesthe current line to be discarded and the system causes 1387afe61c15SRodney W. Grimesthe terminal 1388afe61c15SRodney W. Grimesto erase the line from the display. 1389afe61c15SRodney W. Grimes.Pp 1390afe61c15SRodney W. GrimesIf 1391afe61c15SRodney W. Grimes.Dv ECHOPRT 1392afe61c15SRodney W. Grimesand 1393afe61c15SRodney W. Grimes.Dv ICANON 1394afe61c15SRodney W. Grimesare set, the system assumes 1395afe61c15SRodney W. Grimesthat the display is a printing device and prints a 1396afe61c15SRodney W. Grimesbackslash and the erased characters when processing 1397afe61c15SRodney W. Grimes.Dv ERASE 1398afe61c15SRodney W. Grimescharacters, followed by a forward slash. 1399afe61c15SRodney W. Grimes.Pp 1400afe61c15SRodney W. GrimesIf 1401afe61c15SRodney W. Grimes.Dv ECHOCTL 1402afe61c15SRodney W. Grimesis set, the system echoes control characters 1403afe61c15SRodney W. Grimesin a visible fashion using a caret followed by the control character. 1404afe61c15SRodney W. Grimes.Pp 1405afe61c15SRodney W. GrimesIf 1406afe61c15SRodney W. Grimes.Dv ALTWERASE 1407afe61c15SRodney W. Grimesis set, the system uses an alternative algorithm 1408afe61c15SRodney W. Grimesfor determining what constitutes a word when processing 1409afe61c15SRodney W. Grimes.Dv WERASE 1410afe61c15SRodney W. Grimescharacters (see 1411afe61c15SRodney W. Grimes.Dv WERASE ) . 1412afe61c15SRodney W. Grimes.Pp 1413afe61c15SRodney W. GrimesIf 1414afe61c15SRodney W. Grimes.Dv ECHONL 1415afe61c15SRodney W. Grimesand 1416afe61c15SRodney W. Grimes.Dv ICANON 1417afe61c15SRodney W. Grimesare set, the 1418afe61c15SRodney W. Grimes.Ql \&\en 1419afe61c15SRodney W. Grimescharacter echoes even if 1420afe61c15SRodney W. Grimes.Dv ECHO 1421afe61c15SRodney W. Grimesis not set. 1422afe61c15SRodney W. Grimes.Pp 1423afe61c15SRodney W. GrimesIf 1424afe61c15SRodney W. Grimes.Dv ICANON 1425b5e7e999SRuslan Ermilovis set, canonical processing is enabled. 1426b5e7e999SRuslan ErmilovThis enables the 1427afe61c15SRodney W. Grimeserase and kill edit functions, and the assembly of input characters into 1428afe61c15SRodney W. Grimeslines delimited by 1429afe61c15SRodney W. Grimes.Dv NL , 1430afe61c15SRodney W. Grimes.Dv EOF , 1431afe61c15SRodney W. Grimesand 1432afe61c15SRodney W. Grimes.Dv EOL , 1433afe61c15SRodney W. Grimesas described in 1434afe61c15SRodney W. Grimes.Sx "Canonical Mode Input Processing" . 1435afe61c15SRodney W. Grimes.Pp 1436afe61c15SRodney W. GrimesIf 1437afe61c15SRodney W. Grimes.Dv ICANON 1438afe61c15SRodney W. Grimesis not set, read requests are satisfied directly from the input 1439b5e7e999SRuslan Ermilovqueue. 1440b5e7e999SRuslan ErmilovA read is not satisfied until at least 14415f1376d7SMike Pritchard.Dv MIN 1442afe61c15SRodney W. Grimesbytes have been 1443afe61c15SRodney W. Grimesreceived or the timeout value 14445f1376d7SMike Pritchard.Dv TIME 1445b5e7e999SRuslan Ermilovexpired between bytes. 1446b5e7e999SRuslan ErmilovThe time value 14475203edcdSRuslan Ermilovrepresents tenths of seconds. 14485203edcdSRuslan ErmilovSee 1449afe61c15SRodney W. Grimes.Sx "Noncanonical Mode Input Processing" 1450afe61c15SRodney W. Grimesfor more details. 1451afe61c15SRodney W. Grimes.Pp 1452afe61c15SRodney W. GrimesIf 1453afe61c15SRodney W. Grimes.Dv ISIG 1454afe61c15SRodney W. Grimesis set, each input character is checked against the special 1455afe61c15SRodney W. Grimescontrol characters 1456afe61c15SRodney W. Grimes.Dv INTR , 1457afe61c15SRodney W. Grimes.Dv QUIT , 1458afe61c15SRodney W. Grimesand 1459afe61c15SRodney W. Grimes.Dv SUSP 1460b5e7e999SRuslan Ermilov(job control only). 1461b5e7e999SRuslan ErmilovIf an input 1462afe61c15SRodney W. Grimescharacter matches one of these control characters, the function 1463b5e7e999SRuslan Ermilovassociated with that character is performed. 1464b5e7e999SRuslan ErmilovIf 1465afe61c15SRodney W. Grimes.Dv ISIG 1466afe61c15SRodney W. Grimesis not set, no 1467b5e7e999SRuslan Ermilovchecking is done. 1468b5e7e999SRuslan ErmilovThus these special input functions are possible only 1469afe61c15SRodney W. Grimesif 1470afe61c15SRodney W. Grimes.Dv ISIG 1471afe61c15SRodney W. Grimesis set. 1472afe61c15SRodney W. Grimes.Pp 1473afe61c15SRodney W. GrimesIf 1474afe61c15SRodney W. Grimes.Dv IEXTEN 1475afe61c15SRodney W. Grimesis set, implementation-defined functions are recognized 1476b5e7e999SRuslan Ermilovfrom the input data. 1477b5e7e999SRuslan ErmilovHow 1478afe61c15SRodney W. Grimes.Dv IEXTEN 1479afe61c15SRodney W. Grimesbeing set 1480afe61c15SRodney W. Grimesinteracts with 1481afe61c15SRodney W. Grimes.Dv ICANON , 1482afe61c15SRodney W. Grimes.Dv ISIG , 1483afe61c15SRodney W. Grimes.Dv IXON , 1484afe61c15SRodney W. Grimesor 1485afe61c15SRodney W. Grimes.Dv IXOFF 1486afe61c15SRodney W. Grimesis implementation defined. 1487afe61c15SRodney W. GrimesIf 1488afe61c15SRodney W. Grimes.Dv IEXTEN 1489afe61c15SRodney W. Grimesis not set, then 1490afe61c15SRodney W. Grimesimplementation-defined functions are not recognized, and the 1491afe61c15SRodney W. Grimescorresponding input characters are not processed as described for 1492afe61c15SRodney W. Grimes.Dv ICANON , 1493afe61c15SRodney W. Grimes.Dv ISIG , 1494afe61c15SRodney W. Grimes.Dv IXON , 1495afe61c15SRodney W. Grimesand 1496afe61c15SRodney W. Grimes.Dv IXOFF . 1497afe61c15SRodney W. Grimes.Pp 1498afe61c15SRodney W. GrimesIf 1499afe61c15SRodney W. Grimes.Dv NOFLSH 1500afe61c15SRodney W. Grimesis set, the normal flush of the input and output queues 1501afe61c15SRodney W. Grimesassociated with the 1502afe61c15SRodney W. Grimes.Dv INTR , 1503afe61c15SRodney W. Grimes.Dv QUIT , 1504afe61c15SRodney W. Grimesand 1505afe61c15SRodney W. Grimes.Dv SUSP 1506afe61c15SRodney W. Grimescharacters 1507afe61c15SRodney W. Grimesare not be done. 1508afe61c15SRodney W. Grimes.Pp 1509afe61c15SRodney W. GrimesIf 1510afe61c15SRodney W. Grimes.Dv TOSTOP 1511afe61c15SRodney W. Grimesis set, the signal 1512afe61c15SRodney W. Grimes.Dv SIGTTOU 1513afe61c15SRodney W. Grimesis sent to the process group of a process that tries to write to 1514afe61c15SRodney W. Grimesits controlling terminal if it is not in the foreground process group for 1515b5e7e999SRuslan Ermilovthat terminal. 1516b5e7e999SRuslan ErmilovThis signal, by default, stops the members of the process group. 1517b5e7e999SRuslan ErmilovOtherwise, the output generated by that process is output to the 1518b5e7e999SRuslan Ermilovcurrent output stream. 1519b5e7e999SRuslan ErmilovProcesses that are blocking or ignoring 1520afe61c15SRodney W. Grimes.Dv SIGTTOU 1521afe61c15SRodney W. Grimessignals are excepted and allowed to produce output and the 1522afe61c15SRodney W. Grimes.Dv SIGTTOU 1523afe61c15SRodney W. Grimessignal 1524afe61c15SRodney W. Grimesis not sent. 1525afe61c15SRodney W. Grimes.Pp 1526afe61c15SRodney W. GrimesIf 1527afe61c15SRodney W. Grimes.Dv NOKERNINFO 1528afe61c15SRodney W. Grimesis set, the kernel does not produce a status message 1529afe61c15SRodney W. Grimeswhen processing 1530afe61c15SRodney W. Grimes.Dv STATUS 1531afe61c15SRodney W. Grimescharacters (see 1532afe61c15SRodney W. Grimes.Dv STATUS ) . 1533afe61c15SRodney W. Grimes.Ss Special Control Characters 1534afe61c15SRodney W. GrimesThe special control characters values are defined by the array 1535afe61c15SRodney W. Grimes.Fa c_cc . 1536afe61c15SRodney W. GrimesThis table lists the array index, the corresponding special character, 1537b5e7e999SRuslan Ermilovand the system default value. 1538b5e7e999SRuslan ErmilovFor an accurate list of 1539afe61c15SRodney W. Grimesthe system defaults, consult the header file 15400ad02507SRemko Lodder.In sys/ttydefaults.h . 1541afe61c15SRodney W. Grimes.Pp 1542afe61c15SRodney W. Grimes.Bl -column "Index Name" "Special Character" -offset indent -compact 1543afe61c15SRodney W. Grimes.It Em "Index Name Special Character Default Value" 1544afe61c15SRodney W. Grimes.It Dv VEOF Ta EOF Ta \&^D 1545afe61c15SRodney W. Grimes.It Dv VEOL Ta EOL Ta _POSIX_VDISABLE 1546afe61c15SRodney W. Grimes.It Dv VEOL2 Ta EOL2 Ta _POSIX_VDISABLE 1547afe61c15SRodney W. Grimes.It Dv VERASE Ta ERASE Ta \&^? Ql \&\e177 1548afe61c15SRodney W. Grimes.It Dv VWERASE Ta WERASE Ta \&^W 1549afe61c15SRodney W. Grimes.It Dv VKILL Ta KILL Ta \&^U 1550afe61c15SRodney W. Grimes.It Dv VREPRINT Ta REPRINT Ta \&^R 1551afe61c15SRodney W. Grimes.It Dv VINTR Ta INTR Ta \&^C 1552afe61c15SRodney W. Grimes.It Dv VQUIT Ta QUIT Ta \&^\e\e Ql \&\e34 1553afe61c15SRodney W. Grimes.It Dv VSUSP Ta SUSP Ta \&^Z 1554afe61c15SRodney W. Grimes.It Dv VDSUSP Ta DSUSP Ta \&^Y 1555afe61c15SRodney W. Grimes.It Dv VSTART Ta START Ta \&^Q 1556afe61c15SRodney W. Grimes.It Dv VSTOP Ta STOP Ta \&^S 1557afe61c15SRodney W. Grimes.It Dv VLNEXT Ta LNEXT Ta \&^V 1558afe61c15SRodney W. Grimes.It Dv VDISCARD Ta DISCARD Ta \&^O 1559afe61c15SRodney W. Grimes.It Dv VMIN Ta --- Ta \&1 1560afe61c15SRodney W. Grimes.It Dv VTIME Ta --- Ta \&0 1561afe61c15SRodney W. Grimes.It Dv VSTATUS Ta STATUS Ta \&^T 1562afe61c15SRodney W. Grimes.El 1563afe61c15SRodney W. Grimes.Pp 1564afe61c15SRodney W. GrimesIf the 1565afe61c15SRodney W. Grimesvalue of one of the changeable special control characters (see 1566afe61c15SRodney W. Grimes.Sx "Special Characters" ) 1567afe61c15SRodney W. Grimesis 1568afe61c15SRodney W. Grimes.Dv {_POSIX_VDISABLE} , 1569afe61c15SRodney W. Grimesthat function is disabled; that is, no input 1570afe61c15SRodney W. Grimesdata is recognized as the disabled special character. 1571afe61c15SRodney W. GrimesIf 1572afe61c15SRodney W. Grimes.Dv ICANON 1573afe61c15SRodney W. Grimesis 1574afe61c15SRodney W. Grimesnot set, the value of 1575afe61c15SRodney W. Grimes.Dv {_POSIX_VDISABLE} 1576afe61c15SRodney W. Grimeshas no special meaning for the 1577afe61c15SRodney W. Grimes.Dv VMIN 1578afe61c15SRodney W. Grimesand 1579afe61c15SRodney W. Grimes.Dv VTIME 1580afe61c15SRodney W. Grimesentries of the 1581afe61c15SRodney W. Grimes.Fa c_cc 1582afe61c15SRodney W. Grimesarray. 1583afe61c15SRodney W. Grimes.Pp 1584afe61c15SRodney W. GrimesThe initial values of the flags and control characters 1585edf0e5b3SMike Pritchardafter 1586edf0e5b3SMike Pritchard.Fn open 1587edf0e5b3SMike Pritchardis set according to 1588afe61c15SRodney W. Grimesthe values in the header 1589fe08efe6SRuslan Ermilov.In sys/ttydefaults.h . 15901f83b37eSEdward Tomasz Napierala.Sh SEE ALSO 15911f83b37eSEdward Tomasz Napierala.Xr stty 1 , 15921f83b37eSEdward Tomasz Napierala.Xr tcgetsid 3 , 15931f83b37eSEdward Tomasz Napierala.Xr tcsendbreak 3 , 15941f83b37eSEdward Tomasz Napierala.Xr tcsetattr 3 , 15951f83b37eSEdward Tomasz Napierala.Xr tcsetsid 3 , 1596*2dcf8c45SMichael Gmelin.Xr tty 4 , 1597*2dcf8c45SMichael Gmelin.Xr stack 9 1598