text: /* vi: set sw=4 ts=4: */
  /*
   * Mini kill/killall[5] implementation for busybox
   *
   * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
   * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   *
   * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   */
  
  //usage:#define kill_trivial_usage
  //usage:       "[-l] [-SIG] PID..."
  //usage:#define kill_full_usage "\n\n"
  //usage:       "Send a signal (default: TERM) to given PIDs\n"
  //usage:     "\n	-l	List all signal names and numbers"
  /* //usage:  "\n	-s SIG	Yet another way of specifying SIG" */
  //usage:
  //usage:#define kill_example_usage
  //usage:       "$ ps | grep apache\n"
  //usage:       "252 root     root     S [apache]\n"
  //usage:       "263 www-data www-data S [apache]\n"
  //usage:       "264 www-data www-data S [apache]\n"
  //usage:       "265 www-data www-data S [apache]\n"
  //usage:       "266 www-data www-data S [apache]\n"
  //usage:       "267 www-data www-data S [apache]\n"
  //usage:       "$ kill 252\n"
  //usage:
  //usage:#define killall_trivial_usage
  //usage:       "[-l] [-q] [-SIG] PROCESS_NAME..."
  //usage:#define killall_full_usage "\n\n"
  //usage:       "Send a signal (default: TERM) to given processes\n"
  //usage:     "\n	-l	List all signal names and numbers"
  /* //usage:  "\n	-s SIG	Yet another way of specifying SIG" */
  //usage:     "\n	-q	Don't complain if no processes were killed"
  //usage:
  //usage:#define killall_example_usage
  //usage:       "$ killall apache\n"
  //usage:
  //usage:#define killall5_trivial_usage
  //usage:       "[-l] [-SIG] [-o PID]..."
  //usage:#define killall5_full_usage "\n\n"
  //usage:       "Send a signal (default: TERM) to all processes outside current session\n"
  //usage:     "\n	-l	List all signal names and numbers"
  //usage:     "\n	-o PID	Don't signal this PID"
  /* //usage:  "\n	-s SIG	Yet another way of specifying SIG" */
  
  #include "libbb.h"
  
  /* Note: kill_main is directly called from shell in order to implement
   * kill built-in. Shell substitutes job ids with process groups first.
   *
   * This brings some complications:
   *
   * + we can't use xfunc here
   * + we can't use applet_name
   * + we can't use bb_show_usage
   * (Above doesn't apply for killall[5] cases)
   *
   * kill %n gets translated into kill ' -<process group>' by shell (note space!)
   * This is needed to avoid collision with kill -9 ... syntax
   */
  
  int kill_main(int argc UNUSED_PARAM, char **argv)
  {
  	char *arg;
  	pid_t pid;
  	int signo = SIGTERM, errors = 0, quiet = 0;
  #if !ENABLE_KILLALL && !ENABLE_KILLALL5
  #define killall 0
  #define killall5 0
  #else
  /* How to determine who we are? find 3rd char from the end:
   * kill, killall, killall5
   *  ^i       ^a        ^l  - it's unique
   * (checking from the start is complicated by /bin/kill... case) */
  	const char char3 = argv[0][strlen(argv[0]) - 3];
  #define killall (ENABLE_KILLALL && char3 == 'a')
  #define killall5 (ENABLE_KILLALL5 && char3 == 'l')
  #endif
  
  	/* Parse any options */
  	arg = *++argv;
  
  	if (!arg || arg[0] != '-') {
  		goto do_it_now;
  	}
  
  	/* The -l option, which prints out signal names.
  	 * Intended usage in shell:
  	 * echo "Died of SIG`kill -l $?`"
  	 * We try to mimic what kill from coreutils-6.8 does */
  	if (arg[1] == 'l' && arg[2] == '\0') {
  		arg = *++argv;
  		if (!arg) {
  			/* Print the whole signal list */
  			print_signames();
  			return 0;
  		}
  		/* -l <sig list> */
  		do {
  			if (isdigit(arg[0])) {
  				signo = bb_strtou(arg, NULL, 10);
  				if (errno) {
  					bb_error_msg("unknown signal '%s'", arg);
  					return EXIT_FAILURE;
  				}
  				/* Exitcodes >= 0x80 are to be treated
  				 * as "killed by signal (exitcode & 0x7f)" */
  				puts(get_signame(signo & 0x7f));
  				/* TODO: 'bad' signal# - coreutils says:
  				 * kill: 127: invalid signal
  				 * we just print "127" instead */
  			} else {
  				signo = get_signum(arg);
  				if (signo < 0) {
  					bb_error_msg("unknown signal '%s'", arg);
  					return EXIT_FAILURE;
  				}
  				printf("%d\n", signo);
  			}
  			arg = *++argv;
  		} while (arg);
  		return EXIT_SUCCESS;
  	}
  
  	/* The -q quiet option */
  	if (killall && arg[1] == 'q' && arg[2] == '\0') {
  		quiet = 1;
  		arg = *++argv;
  		if (!arg)
  			bb_show_usage();
  		if (arg[0] != '-')
  			goto do_it_now;
  	}
  
  	arg++; /* skip '-' */
  
  	/* -o PID? (if present, it always is at the end of command line) */
  	if (killall5 && arg[0] == 'o')
  		goto do_it_now;
  
  	if (argv[1] && arg[0] == 's' && arg[1] == '\0') { /* -s SIG? */
  		arg = *++argv;
  	} /* else it must be -SIG */
  	signo = get_signum(arg);
  	if (signo < 0) { /* || signo > MAX_SIGNUM ? */
  		bb_error_msg("bad signal name '%s'", arg);
  		return EXIT_FAILURE;
  	}
  	arg = *++argv;
  
   do_it_now:
  	pid = getpid();
  
  	if (killall5) {
  		pid_t sid;
  		procps_status_t* p = NULL;
  		/* compat: exitcode 2 is "no one was signaled" */
  		int ret = 2;
  
  		/* Find out our session id */
  		sid = getsid(pid);
  		/* Stop all processes */
  		if (signo != SIGSTOP && signo != SIGCONT)
  			kill(-1, SIGSTOP);
  		/* Signal all processes except those in our session */
  		while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID)) != NULL) {
  			char **args;
  
  			if (p->sid == (unsigned)sid
  			 || p->sid == 0 /* compat: kernel thread, don't signal it */
  			 || p->pid == (unsigned)pid
  			 || p->pid == 1
  			) {
  				continue;
  			}
  
  			/* All remaining args must be -o PID options.
  			 * Check p->pid against them. */
  			args = argv;
  			while (*args) {
  				pid_t omit;
  
  				arg = *args++;
  				if (arg[0] != '-' || arg[1] != 'o') {
  					bb_error_msg("bad option '%s'", arg);
  					ret = 1;
  					goto resume;
  				}
  				arg += 2;
  				if (!arg[0] && *args)
  					arg = *args++;
  				omit = bb_strtoi(arg, NULL, 10);
  				if (errno) {
  					bb_error_msg("invalid number '%s'", arg);
  					ret = 1;
  					goto resume;
  				}
  				if (p->pid == omit)
  					goto dont_kill;
  			}
  			kill(p->pid, signo);
  			ret = 0;
   dont_kill: ;
  		}
   resume:
  		/* And let them continue */
  		if (signo != SIGSTOP && signo != SIGCONT)
  			kill(-1, SIGCONT);
  		return ret;
  	}
  
  	/* Pid or name is required for kill/killall */
  	if (!arg) {
  		bb_error_msg("you need to specify whom to kill");
  		return EXIT_FAILURE;
  	}
  
  	if (killall) {
  		/* Looks like they want to do a killall.  Do that */
  		do {
  			pid_t* pidList;
  
  			pidList = find_pid_by_name(arg);
  			if (*pidList == 0) {
  				errors++;
  				if (!quiet)
  					bb_error_msg("%s: no process killed", arg);
  			} else {
  				pid_t *pl;
  
  				for (pl = pidList; *pl; pl++) {
  					if (*pl == pid)
  						continue;
  					if (kill(*pl, signo) == 0)
  						continue;
  					errors++;
  					if (!quiet)
  						bb_perror_msg("can't kill pid %d", (int)*pl);
  				}
  			}
  			free(pidList);
  			arg = *++argv;
  		} while (arg);
  		return errors;
  	}
  
  	/* Looks like they want to do a kill. Do that */
  	while (arg) {
  #if ENABLE_ASH || ENABLE_HUSH
  		/*
  		 * We need to support shell's "hack formats" of
  		 * " -PRGP_ID" (yes, with a leading space)
  		 * and " PID1 PID2 PID3" (with degenerate case "")
  		 */
  		while (*arg != '\0') {
  			char *end;
  			if (*arg == ' ')
  				arg++;
  			pid = bb_strtoi(arg, &end, 10);
  			if (errno && (errno != EINVAL || *end != ' ')) {
  				bb_error_msg("invalid number '%s'", arg);
  				errors++;
  				break;
  			}
  			if (kill(pid, signo) != 0) {
  				bb_perror_msg("can't kill pid %d", (int)pid);
  				errors++;
  			}
  			arg = end; /* can only point to ' ' or '\0' now */
  		}
  #else
  		pid = bb_strtoi(arg, NULL, 10);
  		if (errno) {
  			bb_error_msg("invalid number '%s'", arg);
  			errors++;
  		} else if (kill(pid, signo) != 0) {
  			bb_perror_msg("can't kill pid %d", (int)pid);
  			errors++;
  		}
  #endif
  		arg = *++argv;
  	}
  	return errors;
  }
  