1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1992-2010 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Common Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
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) 2008-03-13 $\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
b_tty(int argc,char * argv[],void * context)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(lflag)
88 {
89 #if _mac_STWLINE
90 if (n = ioctl(0, STWLINE, 0)) >= 0)
91 error(ERROR_OUTPUT, 1, "synchronous line %d", n);
92 else
93 #endif
94 error(ERROR_OUTPUT, 1, "not on an active synchronous line");
95 }
96 return(error_info.errors);
97 }
98