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Diffstat (limited to 'src/tty.c')
-rw-r--r-- | src/tty.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/src/tty.c b/src/tty.c new file mode 100644 index 000000000..056c7da8d --- /dev/null +++ b/src/tty.c @@ -0,0 +1,88 @@ +/* tty -- print the path of the terminal connected to standard input + Copyright (C) 1990, 1991 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* Displays "not a tty" if stdin is not a terminal. + Displays nothing if -s option is given. + Exit status 0 if stdin is a tty, 1 if not, 2 if usage error. + + Written by David MacKenzie (djm@ai.mit.edu). */ + +#include <stdio.h> +#include <getopt.h> +#include <sys/types.h> +#include "system.h" + +void usage (); + +/* The name under which this program was run. */ +char *program_name; + +/* If nonzero, return an exit status but produce no output. */ +int silent; + +struct option longopts[] = +{ + {"silent", 0, NULL, 's'}, + {"quiet", 0, NULL, 's'}, + {NULL, 0, NULL, 0} +}; + +void +main (argc, argv) + int argc; + char **argv; +{ + char *tty; + int optc; + + program_name = argv[0]; + silent = 0; + + while ((optc = getopt_long (argc, argv, "s", longopts, (int *) 0)) != EOF) + { + switch (optc) + { + case 's': + silent = 1; + break; + default: + usage (); + } + } + + if (optind != argc) + usage (); + + tty = ttyname (0); + if (!silent) + { + if (tty) + puts (tty); + else + puts ("not a tty"); + } + + exit (tty == NULL); +} + +void +usage () +{ + fprintf (stderr, "\ +Usage: %s [-s] [--silent] [--quiet]\n", program_name); + exit (2); +} |