1.\" Copyright (c) 1992, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)zopen.3 8.1 (Berkeley) 6/9/93 33.\" 34.Dd June 9, 1993 35.Dt ZOPEN 3 36.Os 37.Sh NAME 38.Nm zopen 39.Nd compressed stream open function 40.Sh SYNOPSIS 41.Fd #include <stdio.h> 42.Ft FILE * 43.Fn zopen "const char *path" "const char *mode" "int bits" 44.Sh DESCRIPTION 45The 46.Fn zopen 47function 48opens the compressed file whose name is the string pointed to by 49.Fa path 50and associates a stream with it. 51.Pp 52The argument 53.Fa mode 54points to one of the following one-character strings: 55.Bl -tag -width indent 56.It Dq Li r 57Open compressed file for reading. 58The stream is positioned at the beginning of the file. 59.It Dq Li w 60Truncate file to zero length or create compressed file for writing. 61The stream is positioned at the beginning of the file. 62.El 63.Pp 64Any created files will have mode 65.Pf \\*q Dv S_IRUSR 66\&| 67.Dv S_IWUSR 68\&| 69.Dv S_IRGRP 70\&| 71.Dv S_IWGRP 72\&| 73.Dv S_IROTH 74\&| 75.Dv S_IWOTH Ns \\*q 76.Pq Li 0666 , 77as modified by the process' 78umask value (see 79.Xr umask 2 ) . 80.Pp 81Files may only be read or written. 82Seek operations are not allowed. 83.Pp 84The 85.Fa bits 86argument, if non-zero, is set to the bits code limit. 87If zero, the default is 16. 88See 89.Fn compress 1 90for more information. 91.Sh RETURN VALUES 92Upon successful completion 93.Fn zopen 94returns a 95.Tn FILE 96pointer. 97Otherwise, 98.Dv NULL 99is returned and the global variable 100.Va errno 101is set to indicate the error. 102.Sh ERRORS 103.Bl -tag -width [EINVAL] 104.It Bq Er EINVAL 105The 106.Fa mode 107or 108.Fa bits 109arguments specified to 110.Fn zopen 111were invalid. 112.It Bq Er EFTYPE 113The compressed file starts with an invalid header, or the compressed 114file is compressed with more bits than can be handled. 115.El 116.Pp 117The 118.Fn zopen 119function may also fail and set 120.Va errno 121for any of the errors specified for the routines 122.Xr fopen 3 123or 124.Xr funopen 3 . 125.Sh SEE ALSO 126.Xr compress 1 , 127.Xr fopen 3 , 128.Xr funopen 3 129.Sh HISTORY 130The 131.Nm zopen 132function 133first appeared in 4.4BSD. 134.Sh BUGS 135The 136.Fn zopen 137function 138may not be portable to systems other than 139.Bx . 140