49 lines
1.1 KiB
C
Executable File
49 lines
1.1 KiB
C
Executable File
/* mesg - enable or disable communications. Author: John J. Ribera */
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/*
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* mesg - enable or disable communications.
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*
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* Usage: mesg [ y | n ]
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*
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* 'mesg n' will turn off group and world permissions of the
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* user's terminal.
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* 'mesg y' will enable group and world to write to the user's
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* tty.
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* mesg with no parameters will put the writeable status
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* onto stdout.
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*
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* Author: John J. Ribera, Jr. 09/09/90
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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_PROTOTYPE( int main, (int argc, char *argv []) );
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int main(argc, argv)
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int argc;
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char *argv[];
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{
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struct stat statb;
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char *tty_name;
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if ((tty_name = ttyname(0)) == NULL) exit(2);
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if (stat(tty_name, &statb) == -1) exit(2);
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if (--argc) {
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if (*argv[1] == 'n') statb.st_mode = 0600;
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else if (*argv[1] == 'y') statb.st_mode = 0620;
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else {
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fprintf(stderr, "mesg: usage: mesg [n|y]\n");
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exit(2);
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}
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if (chmod(tty_name, statb.st_mode) == -1) exit(2);
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} else printf((statb.st_mode & 020) ? "is y\n" : "is n\n");
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if (statb.st_mode & 020) exit(0);
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exit(1);
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}
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