pgrep.c

/*
 * pgrep/pkill -- utilities to filter the process table
 *
 * Copyright 2000 Kjetil Torgrim Homme <kjetilho@ifi.uio.no>
 * Changes by Albert Cahalan, 2002,2006.
 * Changes by Roberto Polli <rpolli@babel.it>, 2012.
 *
 * 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
 * of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <unistd.h>
#include <ctype.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
#include <regex.h>
#include <errno.h>
#include <getopt.h>

/* EXIT_SUCCESS is 0 */
/* EXIT_FAILURE is 1 */
#define EXIT_USAGE 2
#define EXIT_FATAL 3
#define XALLOC_EXIT_CODE EXIT_FATAL

#define CMDSTRSIZE 4096

#include "c.h"
#include "fileutils.h"
#include "nls.h"
#include "xalloc.h"
#include "proc/readproc.h"
#include "proc/sig.h"
#include "proc/devname.h"
#include "proc/sysinfo.h"
#include "proc/version.h" /* procps_version */

static int i_am_pkill = 0;

struct el {
	long	num;
	char *	str;
};

/* User supplied arguments */

static int opt_full = 0;
static int opt_long = 0;
static int opt_longlong = 0;
static int opt_oldest = 0;
static int opt_newest = 0;
static int opt_negate = 0;
static int opt_exact = 0;
static int opt_count = 0;
static int opt_signal = SIGTERM;
static int opt_lock = 0;
static int opt_case = 0;
static int opt_echo = 0;
static int opt_threads = 0;

static const char *opt_delim = "\n";
static struct el *opt_pgrp = NULL;
static struct el *opt_rgid = NULL;
static struct el *opt_pid = NULL;
static struct el *opt_ppid = NULL;
static struct el *opt_sid = NULL;
static struct el *opt_term = NULL;
static struct el *opt_euid = NULL;
static struct el *opt_ruid = NULL;
static char *opt_pattern = NULL;
static char *opt_pidfile = NULL;

static int __attribute__ ((__noreturn__)) usage(int opt)
{
	int err = (opt == '?');
	FILE *fp = err ? stderr : stdout;

	fputs(USAGE_HEADER, fp);
	fprintf(fp, _(" %s [options] <pattern>\n"), program_invocation_short_name);
	fputs(USAGE_OPTIONS, fp);
	if (i_am_pkill == 0) {
		fputs(_(" -d, --delimiter <string>  specify output delimiter\n"
			" -l, --list-name           list PID and process name\n"
			" -v, --inverse             negates the matching\n"
			" -w, --lightweight         list all TID\n"
		), fp);
	}
	if (i_am_pkill == 1) {
		fputs(_(" -<sig>, --signal <sig>    signal to send (either number or name)\n"
			" -e, --echo                display what is killed\n"), fp);
	}
	fputs(_(" -c, --count               count of matching processes\n"
		" -f, --full                use full process name to match\n"
		" -g, --pgroup <id,...>     match listed process group IDs\n"
		" -G, --group <gid,...>     match real group IDs\n"
		" -n, --newest              select most recently started\n"
		" -o, --oldest              select least recently started\n"
		" -P, --parent <ppid,...>   match only child processes of the given parent\n"
		" -s, --session <sid,...>   match session IDs\n"
		" -t, --terminal <tty,...>  match by controlling terminal\n"
		" -u, --euid <id,...>       match by effective IDs\n"
		" -U, --uid <id,...>        match by real IDs\n"
		" -x, --exact               match exactly with the command name\n"
		" -F, --pidfile <file>      read PIDs from file\n"
		" -L, --logpidfile          fail if PID file is not locked\n"), fp);
	fputs(USAGE_SEPARATOR, fp);
	fputs(USAGE_HELP, fp);
	fputs(USAGE_VERSION, fp);
	fprintf(fp, USAGE_MAN_TAIL("pgrep(1)"));

	exit(fp == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}

static struct el *split_list (const char *restrict str, int (*convert)(const char *, struct el *))
{
	char *copy = xstrdup (str);
	char *ptr = copy;
	char *sep_pos;
	int i = 0;
	int size = 0;
	struct el *list = NULL;

	do {
		if (i == size) {
			size = size * 5 / 4 + 4;
			/* add 1 because slot zero is a count */
			list = xrealloc (list, 1 + size * sizeof *list);
		}
		sep_pos = strchr (ptr, ',');
		if (sep_pos)
			*sep_pos = 0;
		/* Use ++i instead of i++ because slot zero is a count */
		if (list && !convert (ptr, &list[++i]))
			exit (EXIT_USAGE);
		if (sep_pos)
			ptr = sep_pos + 1;
	} while (sep_pos);

	free (copy);
	if (!i) {
		free (list);
		list = NULL;
	} else {
		list[0].num = i;
	}
	return list;
}

/* strict_atol returns a Boolean: TRUE if the input string
 * contains a plain number, FALSE if there are any non-digits. */
static int strict_atol (const char *restrict str, long *restrict value)
{
	int res = 0;
	int sign = 1;

	if (*str == '+')
		++str;
	else if (*str == '-') {
		++str;
		sign = -1;
	}

	for ( ; *str; ++str) {
		if (! isdigit (*str))
			return (0);
		res *= 10;
		res += *str - '0';
	}
	*value = sign * res;
	return 1;
}

#include <sys/file.h>

/* We try a read lock. The daemon should have a write lock.
 * Seen using flock: FreeBSD code */
static int has_flock(int fd)
{
	return flock(fd, LOCK_SH|LOCK_NB)==-1 && errno==EWOULDBLOCK;
}

/* We try a read lock. The daemon should have a write lock.
 * Seen using fcntl: libslack */
static int has_fcntl(int fd)
{
	struct flock f;  /* seriously, struct flock is for a fnctl lock! */
	f.l_type = F_RDLCK;
	f.l_whence = SEEK_SET;
	f.l_start = 0;
	f.l_len = 0;
	return fcntl(fd,F_SETLK,&f)==-1 && (errno==EACCES || errno==EAGAIN);
}

static struct el *read_pidfile(void)
{
	char buf[12];
	int fd;
	struct stat sbuf;
	char *endp;
	int n, pid;
	struct el *list = NULL;

	fd = open(opt_pidfile, O_RDONLY|O_NOCTTY|O_NONBLOCK);
	if(fd<0)
		goto just_ret;
	if(fstat(fd,&sbuf) || !S_ISREG(sbuf.st_mode) || sbuf.st_size<1)
		goto out;
	/* type of lock, if any, is not standardized on Linux */
	if(opt_lock && !has_flock(fd) && !has_fcntl(fd))
		goto out;
	memset(buf,'\0',sizeof buf);
	n = read(fd,buf+1,sizeof buf-2);
	if (n<1)
		goto out;
	pid = strtoul(buf+1,&endp,10);
	if(endp<=buf+1 || pid<1 || pid>0x7fffffff)
		goto out;
	if(*endp && !isspace(*endp))
		goto out;
	list = xmalloc(2 * sizeof *list);
	list[0].num = 1;
	list[1].num = pid;
out:
	close(fd);
just_ret:
	return list;
}

static int conv_uid (const char *restrict name, struct el *restrict e)
{
	struct passwd *pwd;

	if (strict_atol (name, &e->num))
		return (1);

	pwd = getpwnam (name);
	if (pwd == NULL) {
		xwarnx(_("invalid user name: %s"), name);
		return 0;
	}
	e->num = pwd->pw_uid;
	return 1;
}


static int conv_gid (const char *restrict name, struct el *restrict e)
{
	struct group *grp;

	if (strict_atol (name, &e->num))
		return 1;

	grp = getgrnam (name);
	if (grp == NULL) {
		xwarnx(_("invalid group name: %s"), name);
		return 0;
	}
	e->num = grp->gr_gid;
	return 1;
}


static int conv_pgrp (const char *restrict name, struct el *restrict e)
{
	if (! strict_atol (name, &e->num)) {
		xwarnx(_("invalid process group: %s"), name);
		return 0;
	}
	if (e->num == 0)
		e->num = getpgrp ();
	return 1;
}


static int conv_sid (const char *restrict name, struct el *restrict e)
{
	if (! strict_atol (name, &e->num)) {
		xwarnx(_("invalid session id: %s"), name);
		return 0;
	}
	if (e->num == 0)
		e->num = getsid (0);
	return 1;
}


static int conv_num (const char *restrict name, struct el *restrict e)
{
	if (! strict_atol (name, &e->num)) {
		xwarnx(_("not a number: %s"), name);
		return 0;
	}
	return 1;
}


static int conv_str (const char *restrict name, struct el *restrict e)
{
	e->str = xstrdup (name);
	return 1;
}


static int match_numlist (long value, const struct el *restrict list)
{
	int found = 0;
	if (list == NULL)
		found = 0;
	else {
		int i;
		for (i = list[0].num; i > 0; i--) {
			if (list[i].num == value)
				found = 1;
		}
	}
	return found;
}

static int match_strlist (const char *restrict value, const struct el *restrict list)
{
	int found = 0;
	if (list == NULL)
		found = 0;
	else {
		int i;
		for (i = list[0].num; i > 0; i--) {
			if (! strcmp (list[i].str, value))
				found = 1;
		}
	}
	return found;
}

static void output_numlist (const struct el *restrict list, int num)
{
	int i;
	const char *delim = opt_delim;
	for (i = 0; i < num; i++) {
		if(i+1==num)
			delim = "\n";
		printf ("%ld%s", list[i].num, delim);
	}
}

static void output_strlist (const struct el *restrict list, int num)
{
/* FIXME: escape codes */
	int i;
	const char *delim = opt_delim;
	for (i = 0; i < num; i++) {
		if(i+1==num)
			delim = "\n";
		printf ("%lu %s%s", list[i].num, list[i].str, delim);
	}
}

static PROCTAB *do_openproc (void)
{
	PROCTAB *ptp;
	int flags = 0;

	if (opt_pattern || opt_full)
		flags |= PROC_FILLCOM;
	if (opt_ruid || opt_rgid)
		flags |= PROC_FILLSTATUS;
	if (opt_oldest || opt_newest || opt_pgrp || opt_sid || opt_term)
		flags |= PROC_FILLSTAT;
	if (!(flags & PROC_FILLSTAT))
		flags |= PROC_FILLSTATUS;  /* FIXME: need one, and PROC_FILLANY broken */
	if (opt_euid && !opt_negate) {
		int num = opt_euid[0].num;
		int i = num;
		uid_t *uids = xmalloc (num * sizeof (uid_t));
		while (i-- > 0) {
			uids[i] = opt_euid[i+1].num;
		}
		flags |= PROC_UID;
		ptp = openproc (flags, uids, num);
	} else {
		ptp = openproc (flags);
	}
	return ptp;
}

static regex_t * do_regcomp (void)
{
	regex_t *preg = NULL;

	if (opt_pattern) {
		char *re;
		char errbuf[256];
		int re_err;

		preg = xmalloc (sizeof (regex_t));
		if (opt_exact) {
			re = xmalloc (strlen (opt_pattern) + 5);
			sprintf (re, "^(%s)$", opt_pattern);
		} else {
			re = opt_pattern;
		}

		re_err = regcomp (preg, re, REG_EXTENDED | REG_NOSUB | opt_case);
		if (re_err) {
			regerror (re_err, preg, errbuf, sizeof(errbuf));
			fputs(errbuf,stderr);
			exit (EXIT_USAGE);
		}
	}
	return preg;
}

static struct el * select_procs (int *num)
{
	PROCTAB *ptp;
	proc_t task;
	unsigned long long saved_start_time;      /* for new/old support */
	pid_t saved_pid = 0;                      /* for new/old support */
	int matches = 0;
	int size = 0;
	regex_t *preg;
	pid_t myself = getpid();
	struct el *list = NULL;
	char cmdline[CMDSTRSIZE];
	char cmdsearch[CMDSTRSIZE];
	char cmdoutput[CMDSTRSIZE];

	ptp = do_openproc();
	preg = do_regcomp();

	if (opt_newest) saved_start_time =  0ULL;
	else saved_start_time = ~0ULL;

	if (opt_newest) saved_pid = 0;
	if (opt_oldest) saved_pid = INT_MAX;

	memset(&task, 0, sizeof (task));
	while(readproc(ptp, &task)) {
		int match = 1;

		if (task.XXXID == myself)
			continue;
		else if (opt_newest && task.start_time < saved_start_time)
			match = 0;
		else if (opt_oldest && task.start_time > saved_start_time)
			match = 0;
		else if (opt_ppid && ! match_numlist (task.ppid, opt_ppid))
			match = 0;
		else if (opt_pid && ! match_numlist (task.tgid, opt_pid))
			match = 0;
		else if (opt_pgrp && ! match_numlist (task.pgrp, opt_pgrp))
			match = 0;
		else if (opt_euid && ! match_numlist (task.euid, opt_euid))
			match = 0;
		else if (opt_ruid && ! match_numlist (task.ruid, opt_ruid))
			match = 0;
		else if (opt_rgid && ! match_numlist (task.rgid, opt_rgid))
			match = 0;
		else if (opt_sid && ! match_numlist (task.session, opt_sid))
			match = 0;
		else if (opt_term) {
			if (task.tty == 0) {
				match = 0;
			} else {
				char tty[256];
				dev_to_tty (tty, sizeof(tty) - 1,
					    task.tty, task.XXXID, ABBREV_DEV);
				match = match_strlist (tty, opt_term);
			}
		}
		if (task.cmdline && (opt_longlong || opt_full) && match && opt_pattern) {
			int i = 0;
			int bytes = sizeof (cmdline) - 1;

			/* make sure it is always NUL-terminated */
			cmdline[bytes] = 0;
			/* make room for SPC in loop below */
			--bytes;

			strncpy (cmdline, task.cmdline[i], bytes);
			bytes -= strlen (task.cmdline[i++]);
			while (task.cmdline[i] && bytes > 0) {
				strncat (cmdline, " ", bytes);
				strncat (cmdline, task.cmdline[i], bytes);
				bytes -= strlen (task.cmdline[i++]) + 1;
			}
		}

		if (opt_long || opt_longlong || (match && opt_pattern)) {
			if (opt_longlong && task.cmdline)
				strncpy (cmdoutput, cmdline, CMDSTRSIZE);
			else
				strncpy (cmdoutput, task.cmd, CMDSTRSIZE);
		}

		if (match && opt_pattern) {
			if (opt_full && task.cmdline)
				strncpy (cmdsearch, cmdline, CMDSTRSIZE);
			else
				strncpy (cmdsearch, task.cmd, CMDSTRSIZE);

			if (regexec (preg, cmdsearch, 0, NULL, 0) != 0)
				match = 0;
		}

		if (match ^ opt_negate) {	/* Exclusive OR is neat */
			if (opt_newest) {
				if (saved_start_time == task.start_time &&
				    saved_pid > task.XXXID)
					continue;
				saved_start_time = task.start_time;
				saved_pid = task.XXXID;
				matches = 0;
			}
			if (opt_oldest) {
				if (saved_start_time == task.start_time &&
				    saved_pid < task.XXXID)
					continue;
				saved_start_time = task.start_time;
				saved_pid = task.XXXID;
				matches = 0;
			}
			if (matches == size) {
				size = size * 5 / 4 + 4;
				list = xrealloc(list, size * sizeof *list);
			}
			if (list && (opt_long || opt_longlong || opt_echo)) {
				list[matches].num = task.XXXID;
				list[matches++].str = xstrdup (cmdoutput);
			} else if (list) {
				list[matches++].num = task.XXXID;
			} else {
				xerrx(EXIT_FAILURE, _("internal error"));
			}

			// pkill does not need subtasks!
			// this control is still done at
			// argparse time, but a further
			// control is free
			if (opt_threads && !i_am_pkill) {
				proc_t subtask;
				memset(&subtask, 0, sizeof (subtask));
				while (readtask(ptp, &task, &subtask)){
					// don't add redundand tasks
					if (task.XXXID == subtask.XXXID)
						continue;

					// eventually grow output buffer
					if (matches == size) {
						size = size * 5 / 4 + 4;
						list = realloc(list, size * sizeof *list);
						if (list == NULL)
							exit (EXIT_FATAL);
					}
					if (opt_long) {
						list[matches].str = xstrdup (cmdoutput);
						list[matches++].num = subtask.XXXID;
					} else {
						list[matches++].num = subtask.XXXID;
					}
					memset(&subtask, 0, sizeof (subtask));
				}
			}



		}





		memset (&task, 0, sizeof (task));
	}
	closeproc (ptp);
	*num = matches;
	return list;
}

static int signal_option(int *argc, char **argv)
{
	int sig;
	int i;
	for (i = 1; i < *argc; i++) {
		if (argv[i][0] == '-') {
			sig = signal_name_to_number(argv[i] + 1);
			if (sig == -1 && isdigit(argv[i][1]))
				sig = atoi(argv[i] + 1);
			if (-1 < sig) {
				memmove(argv + i, argv + i + 1,
					sizeof(char *) * (*argc - i));
				(*argc)--;
				return sig;
			}
		}
	}
	return -1;
}

static void parse_opts (int argc, char **argv)
{
	char opts[32] = "";
	int opt;
	int criteria_count = 0;

	enum {
		SIGNAL_OPTION = CHAR_MAX + 1
	};
	static const struct option longopts[] = {
		{"signal", required_argument, NULL, SIGNAL_OPTION},
		{"count", no_argument, NULL, 'c'},
		{"delimiter", required_argument, NULL, 'd'},
		{"list-name", no_argument, NULL, 'l'},
		{"list-full", no_argument, NULL, 'a'},
		{"full", no_argument, NULL, 'f'},
		{"pgroup", required_argument, NULL, 'g'},
		{"group", required_argument, NULL, 'G'},
		{"newest", no_argument, NULL, 'n'},
		{"oldest", no_argument, NULL, 'o'},
		{"parent", required_argument, NULL, 'P'},
		{"session", required_argument, NULL, 's'},
		{"terminal", required_argument, NULL, 't'},
		{"euid", required_argument, NULL, 'u'},
		{"uid", required_argument, NULL, 'U'},
		{"inverse", no_argument, NULL, 'v'},
		{"lightweight", no_argument, NULL, 'w'},
		{"exact", no_argument, NULL, 'x'},
		{"pidfile", required_argument, NULL, 'F'},
		{"logpidfile", no_argument, NULL, 'L'},
		{"echo", no_argument, NULL, 'e'},
		{"help", no_argument, NULL, 'h'},
		{"version", no_argument, NULL, 'V'},
		{NULL, 0, NULL, 0}
	};

	if (strstr (program_invocation_short_name, "pkill")) {
		int sig;
		i_am_pkill = 1;
		sig = signal_option(&argc, argv);
		if (-1 < sig)
			opt_signal = sig;
		/* These options are for pkill only */
		strcat (opts, "e");
	} else {
		/* These options are for pgrep only */
		strcat (opts, "lad:vw");
	}

	strcat (opts, "LF:cfnoxP:g:s:u:U:G:t:?Vh");

	while ((opt = getopt_long (argc, argv, opts, longopts, NULL)) != -1) {
		switch (opt) {
		case SIGNAL_OPTION:
			opt_signal = signal_name_to_number (optarg);
			if (opt_signal == -1 && isdigit (optarg[0]))
				opt_signal = atoi (optarg);
			break;
		case 'e':
			opt_echo = 1;
			break;
/*		case 'D':   / * FreeBSD: print info about non-matches for debugging * /
 *			break; */
		case 'F':   /* FreeBSD: the arg is a file containing a PID to match */
			opt_pidfile = xstrdup (optarg);
			++criteria_count;
			break;
		case 'G':   /* Solaris: match rgid/rgroup */
			opt_rgid = split_list (optarg, conv_gid);
			if (opt_rgid == NULL)
				usage (opt);
			++criteria_count;
			break;
/*		case 'I':   / * FreeBSD: require confirmation before killing * /
 *			break; */
/*		case 'J':   / * Solaris: match by project ID (name or number) * /
 *			break; */
		case 'L':   /* FreeBSD: fail if pidfile (see -F) not locked */
			opt_lock++;
			break;
/*		case 'M':   / * FreeBSD: specify core (OS crash dump) file * /
 *			break; */
/*		case 'N':   / * FreeBSD: specify alternate namelist file (for us, System.map -- but we don't need it) * /
 *			break; */
		case 'P':   /* Solaris: match by PPID */
			opt_ppid = split_list (optarg, conv_num);
			if (opt_ppid == NULL)
				usage (opt);
			++criteria_count;
			break;
/*		case 'S':   / * FreeBSD: don't ignore the built-in kernel tasks * /
 *			break; */
/*		case 'T':   / * Solaris: match by "task ID" (probably not a Linux task) * /
 *			break; */
		case 'U':   /* Solaris: match by ruid/rgroup */
			opt_ruid = split_list (optarg, conv_uid);
			if (opt_ruid == NULL)
				usage (opt);
			++criteria_count;
			break;
		case 'V':
			printf(PROCPS_NG_VERSION);
			exit(EXIT_SUCCESS);
/*		case 'c':   / * Solaris: match by contract ID * /
 *			break; */
		case 'c':
			opt_count = 1;
			break;
		case 'd':   /* Solaris: change the delimiter */
			opt_delim = xstrdup (optarg);
			break;
		case 'f':   /* Solaris: match full process name (as in "ps -f") */
			opt_full = 1;
			break;
		case 'g':   /* Solaris: match pgrp */
			opt_pgrp = split_list (optarg, conv_pgrp);
			if (opt_pgrp == NULL)
				usage (opt);
			++criteria_count;
			break;
/*		case 'i':   / * FreeBSD: ignore case. OpenBSD: withdrawn. See -I. This sucks. * /
 *			if (opt_case)
 *				usage (opt);
 *			opt_case = REG_ICASE;
 *			break; */
/*		case 'j':   / * FreeBSD: restricted to the given jail ID * /
 *			break; */
		case 'l':   /* Solaris: long output format (pgrep only) Should require -f for beyond argv[0] maybe? */
			opt_long = 1;
			break;
		case 'a':
			opt_longlong = 1;
			break;
		case 'n':   /* Solaris: match only the newest */
			if (opt_oldest|opt_negate|opt_newest)
				usage (opt);
			opt_newest = 1;
			++criteria_count;
			break;
		case 'o':   /* Solaris: match only the oldest */
			if (opt_oldest|opt_negate|opt_newest)
				usage (opt);
			opt_oldest = 1;
			++criteria_count;
			break;
		case 's':   /* Solaris: match by session ID -- zero means self */
			opt_sid = split_list (optarg, conv_sid);
			if (opt_sid == NULL)
				usage (opt);
			++criteria_count;
			break;
		case 't':   /* Solaris: match by tty */
			opt_term = split_list (optarg, conv_str);
			if (opt_term == NULL)
				usage (opt);
			++criteria_count;
			break;
		case 'u':   /* Solaris: match by euid/egroup */
			opt_euid = split_list (optarg, conv_uid);
			if (opt_euid == NULL)
				usage (opt);
			++criteria_count;
			break;
		case 'v':   /* Solaris: as in grep, invert the matching (uh... applied after selection I think) */
			if (opt_oldest|opt_negate|opt_newest)
				usage (opt);
			opt_negate = 1;
			break;
		case 'w':   // Linux: show threads (lightweight process) too
			opt_threads = 1;
			break;
		/* OpenBSD -x, being broken, does a plain string */
		case 'x':   /* Solaris: use ^(regexp)$ in place of regexp (FreeBSD too) */
			opt_exact = 1;
			break;
/*		case 'z':   / * Solaris: match by zone ID * /
 *			break; */
		case 'h':
			usage (opt);
			break;
		case '?':
			usage (optopt ? optopt : opt);
			break;
		}
	}

	if(opt_lock && !opt_pidfile)
		xerrx(EXIT_FAILURE, _("-L without -F makes no sense\n"
				     "Try `%s --help' for more information."),
				     program_invocation_short_name);

	if(opt_pidfile){
		opt_pid = read_pidfile();
		if(!opt_pid)
			xerrx(EXIT_FAILURE, _("pidfile not valid\n"
					     "Try `%s --help' for more information."),
					     program_invocation_short_name);
	}

	if (argc - optind == 1)
		opt_pattern = argv[optind];
	else if (argc - optind > 1)
		xerrx(EXIT_FAILURE, _("only one pattern can be provided\n"
				     "Try `%s --help' for more information."),
				     program_invocation_short_name);
	else if (criteria_count == 0)
		xerrx(EXIT_FAILURE, _("no matching criteria specified\n"
				     "Try `%s --help' for more information."),
				     program_invocation_short_name);
}


int main (int argc, char **argv)
{
	struct el *procs;
	int num;

#ifdef HAVE_PROGRAM_INVOCATION_NAME
	program_invocation_name = program_invocation_short_name;
#endif
	setlocale (LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);
	atexit(close_stdout);

	parse_opts (argc, argv);

	procs = select_procs (&num);
	if (i_am_pkill) {
		int i;
		for (i = 0; i < num; i++) {
			if (kill (procs[i].num, opt_signal) != -1) {
				if (opt_echo)
					printf(_("%s killed (pid %lu)\n"), procs[i].str, procs[i].num);
				continue;
			}
			if (errno==ESRCH)
				 /* gone now, which is OK */
				continue;
			xwarn(_("killing pid %ld failed"), procs[i].num);
		}
		if (opt_count)
			fprintf(stdout, "%d\n", num);
	} else {
		if (opt_count) {
			fprintf(stdout, "%d\n", num);
		} else {
			if (opt_long || opt_longlong)
				output_strlist (procs,num);
			else
				output_numlist (procs,num);
		}
	}
	return !num; /* exit(EXIT_SUCCESS) if match, otherwise exit(EXIT_FAILURE) */
}