avoid null pointer on machine check printf's

[unix-history] / usr / src / bin / kill / kill.c

/*
* Copyright (c) 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)kill.c      4.5 (Berkeley) %G%";
#endif /* not lint */

#include <signal.h>
#include <stdio.h>
#include <ctype.h>

static char *signals[] = {
       "hup", "int", "quit", "ill", "trap", "iot",             /*  1 - 6  */
       "emt", "fpe", "kill", "bus", "segv", "sys",             /*  7 - 12 */
       "pipe", "alrm",  "term", "urg", "stop", "tstp",         /* 13 - 18 */
       "cont", "chld", "ttin", "ttou", "io", "xcpu",           /* 19 - 24 */
       "xfsz", "vtalrm", "prof", "winch", "29", "usr1",        /* 25 - 30 */
       "usr2", NULL,                                           /* 31 - 32 */
       };

main(argc, argv)
       int argc;
       char **argv;
{
       register int numsig;
       register char **p;
       int errors;

       if (argc < 2)
               usage();

       if (!strcmp(*++argv, "-l")) {
               printsig();
               exit(0);
       }

       numsig = SIGTERM;
       if (**argv == '-') {
               ++*argv;
               if (isalpha(**argv)) {
                       if (!strncasecmp(*argv, "sig", 3))
                               *argv += 3;
                       for (p = signals;; ++p) {
                               if (!*p)
                                       goto error;
                               if (!strcasecmp(*p, *argv)) {
                                       numsig = p - signals + 1;
                                       break;
                               }
                       }
               }
               else if (isdigit(**argv)) {
                       numsig = atoi(*argv);
                       if (numsig <= 0 || numsig > NSIG)
                               goto error;
               }
               else {
error:                  printf("kill: unknown signal %s; valid signals:\n", *argv);
                       printsig();
                       exit(1);
               }
               ++argv;
       }

       if (!*argv)
               usage();

       for (errors = 0; *argv; ++argv) {
               if (!isdigit(**argv))
                       usage();
               if (kill(atoi(*argv), numsig) == -1) {
                       perror(*argv);
                       errors = 1;
               }
       }
       exit(errors);
}

static
printsig()
{
       register char **p;

       for (p = signals; *p; ++p) {
               printf("%s ", *p);
               if ((p - signals) == NSIG / 2 - 1)
                       printf("\n");
       }
       printf("\n");
}

static
usage()
{
       printf("usage: kill [-l] [-sig] pid ...\n");
       exit(2);
}