1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1992-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * * 20 ***********************************************************************/ 21 #pragma prototyped 22 /* 23 * David Korn 24 * AT&T Bell Laboratories 25 * 26 * tty 27 */ 28 29 static const char usage[] = 30 "[-?\n@(#)$Id: tty (AT&T Research) 2007-03-11 $\n]" 31 USAGE_LICENSE 32 "[+NAME?tty - write the name of the terminal to standard output]" 33 "[+DESCRIPTION?\btty\b writes the name of the terminal that is connected " 34 "to standard input onto standard output. If the standard input is not " 35 "a terminal, \"\bnot a tty\b\" will be written to standard output.]" 36 "[l:line-number?Write the synchronous line number of the terminal on a " 37 "separate line following the terminal name line. If the standard " 38 "input is not a synchronous terminal then " 39 "\"\bnot on an active synchronous line\b\" is written.]" 40 "[s:silent|quiet?Disable the terminal name line. Use \b[[ -t 0 ]]]]\b instead.]" 41 "[+EXIT STATUS?]{" 42 "[+0?Standard input is a tty.]" 43 "[+1?Standard input is not a tty.]" 44 "[+2?Invalid arguments.]" 45 "[+3?A an error occurred.]" 46 "}" 47 ; 48 49 50 #include <cmd.h> 51 52 #if _mac_STWLINE 53 #include <sys/stermio.h> 54 #endif 55 56 int 57 b_tty(int argc, char *argv[], void* context) 58 { 59 register int n,sflag=0,lflag=0; 60 register char *tty; 61 62 cmdinit(argc, argv, context, ERROR_CATALOG, 0); 63 while (n = optget(argv, usage)) switch (n) 64 { 65 case 'l': 66 lflag++; 67 break; 68 case 's': 69 sflag++; 70 break; 71 case ':': 72 error(2, "%s", opt_info.arg); 73 break; 74 case '?': 75 error(ERROR_usage(2), "%s", opt_info.arg); 76 break; 77 } 78 if(error_info.errors) 79 error(ERROR_usage(2), "%s", optusage(NiL)); 80 if(!(tty=ttyname(0))) 81 { 82 tty = ERROR_translate(0, 0, 0, "not a tty"); 83 error_info.errors++; 84 } 85 if(!sflag) 86 sfputr(sfstdout,tty,'\n'); 87 #if _mac_STWLINE 88 if(lflag && (n = ioctl(0, STWLINE, 0)) >= 0) 89 error(ERROR_OUTPUT, 1, "synchronous line %d", n); 90 else 91 #endif 92 error(ERROR_OUTPUT, 1, "not on an active synchronous line"); 93 return(error_info.errors); 94 } 95