xref: /freebsd/bin/ps/ps.c (revision ca62e195dda11047a04335041811c4a8a6778d2b)

/*-
 * Copyright (c) 1990, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ------+---------+---------+-------- + --------+---------+---------+---------*
 * Copyright (c) 2004  - Garance Alistair Drosehn <gad@FreeBSD.org>.
 * All rights reserved.
 *
 * Significant modifications made to bring `ps' options somewhat closer
 * to the standard for `ps' as described in SingleUnixSpec-v3.
 * ------+---------+---------+-------- + --------+---------+---------+---------*
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1990, 1993, 1994\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#if 0
#ifndef lint
static char sccsid[] = "@(#)ps.c	8.4 (Berkeley) 4/2/94";
#endif /* not lint */
#endif

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/user.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <kvm.h>
#include <limits.h>
#include <locale.h>
#include <paths.h>
#include <pwd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ps.h"

#define	W_SEP	" \t"		/* "Whitespace" list separators */
#define	T_SEP	","		/* "Terminate-element" list separators */

#ifdef LAZY_PS
#define	DEF_UREAD	0;
#define	OPT_LAZY_f	"f"
#else
#define	DEF_UREAD	1;	/* Always do the more-expensive read. */
#define	OPT_LAZY_f		/* I.e., the `-f' option is not added. */
#endif

int	 cflag;			/* -c */
int	 eval;			/* Exit value */
time_t	 now;			/* Current time(3) value */
int	 rawcpu;		/* -C */
int	 sumrusage;		/* -S */
int	 termwidth;		/* Width of the screen (0 == infinity). */
int	 totwidth;		/* Calculated-width of requested variables. */

struct varent *vhead;

static int	 forceuread = DEF_UREAD; /* Do extra work to get u-area. */
static kvm_t	*kd;
static KINFO	*kinfo;
static int	 needcomm;	/* -o "command" */
static int	 needenv;	/* -e */
static int	 needuser;	/* -o "user" */
static int	 optfatal;	/* Fatal error parsing some list-option. */

static enum sort { DEFAULT, SORTMEM, SORTCPU } sortby = DEFAULT;

struct listinfo;
typedef	int	addelem_rtn(struct listinfo *_inf, const char *_elem);

struct listinfo {
	int		 count;
	int		 maxcount;
	int		 elemsize;
	addelem_rtn	*addelem;
	const char	*lname;
	union {
		gid_t	*gids;
		pid_t	*pids;
		dev_t	*ttys;
		uid_t	*uids;
		void	*ptr;
	};
};

static int	 addelem_gid(struct listinfo *, const char *);
static int	 addelem_pid(struct listinfo *, const char *);
static int	 addelem_tty(struct listinfo *, const char *);
static int	 addelem_uid(struct listinfo *, const char *);
static void	 add_list(struct listinfo *, const char *);
static void	 dynsizevars(KINFO *);
static void	*expand_list(struct listinfo *);
static const char *fmt(char **(*)(kvm_t *, const struct kinfo_proc *, int),
		    KINFO *, char *, int);
static void	 free_list(struct listinfo *);
static void	 init_list(struct listinfo *, addelem_rtn, int, const char *);
static char	*kludge_oldps_options(char *);
static int	 pscomp(const void *, const void *);
static void	 saveuser(KINFO *);
static void	 scanvars(void);
static void	 sizevars(void);
static void	 usage(void);

static char dfmt[] = "pid,tt,state,time,command";
static char jfmt[] = "user,pid,ppid,pgid,jobc,state,tt,time,command";
static char lfmt[] = "uid,pid,ppid,cpu,pri,nice,vsz,rss,mwchan,state,"
			"tt,time,command";
static char   o1[] = "pid";
static char   o2[] = "tt,state,time,command";
static char ufmt[] = "user,pid,%cpu,%mem,vsz,rss,tt,state,start,time,command";
static char vfmt[] = "pid,state,time,sl,re,pagein,vsz,rss,lim,tsiz,"
			"%cpu,%mem,command";
static char Zfmt[] = "label";

#define	PS_ARGS	"AaCc" OPT_LAZY_f "G:gHhjLlM:mN:O:o:p:rSTt:U:uvwXxZ"

int
main(int argc, char *argv[])
{
	struct listinfo gidlist, pgrplist, pidlist;
	struct listinfo ruidlist, sesslist, ttylist, uidlist;
	struct kinfo_proc *kp;
	struct varent *vent;
	struct winsize ws;
	const char *cp, *nlistf, *memf;
	char *cols;
	int all, ch, dropgid, elem, flag, _fmt, i, lineno;
	int nentries, nocludge, nkept, nselectors;
	int prtheader, showthreads, wflag, what, xkeep, xkeep_implied;
	char errbuf[_POSIX2_LINE_MAX];

	(void) setlocale(LC_ALL, "");
	/* Set the time to what it is right now. */
	time(&now);

	if ((cols = getenv("COLUMNS")) != NULL && *cols != '\0')
		termwidth = atoi(cols);
	else if ((ioctl(STDOUT_FILENO, TIOCGWINSZ, (char *)&ws) == -1 &&
	     ioctl(STDERR_FILENO, TIOCGWINSZ, (char *)&ws) == -1 &&
	     ioctl(STDIN_FILENO,  TIOCGWINSZ, (char *)&ws) == -1) ||
	     ws.ws_col == 0)
		termwidth = 79;
	else
		termwidth = ws.ws_col - 1;

	/*
	 * Don't apply a kludge if the first argument is an option taking an
	 * argument
	 */
	if (argc > 1) {
		nocludge = 0;
		if (argv[1][0] == '-') {
			for (cp = PS_ARGS; *cp != '\0'; cp++) {
				if (*cp != ':')
					continue;
				if (*(cp - 1) == argv[1][1]) {
					nocludge = 1;
					break;
				}
			}
		}
		if (nocludge == 0)
			argv[1] = kludge_oldps_options(argv[1]);
	}

	xkeep = -1;				/* Neither -x nor -X */
	all = _fmt = nselectors = prtheader = wflag = xkeep_implied = 0;
	init_list(&gidlist, addelem_gid, sizeof(gid_t), "group");
	init_list(&pgrplist, addelem_pid, sizeof(pid_t), "process group");
	init_list(&pidlist, addelem_pid, sizeof(pid_t), "process id");
	init_list(&ruidlist, addelem_uid, sizeof(uid_t), "ruser");
	init_list(&sesslist, addelem_pid, sizeof(pid_t), "session id");
	init_list(&ttylist, addelem_tty, sizeof(dev_t), "tty");
	init_list(&uidlist, addelem_uid, sizeof(uid_t), "user");
	dropgid = 0;
	optfatal = 0;
	memf = nlistf = _PATH_DEVNULL;
	showthreads = 0;
	while ((ch = getopt(argc, argv, PS_ARGS)) != -1)
		switch((char)ch) {
		case 'A':
			/*
			 * Exactly the same as `-ax'.   This has been
			 * added for compatability with SUSv3, but for
			 * now it will not be described in the man page.
			 */
			nselectors++;
			all = xkeep = 1;
			break;
		case 'a':
			nselectors++;
			all = 1;
			break;
		case 'C':
			rawcpu = 1;
			break;
		case 'c':
			cflag = 1;
			break;
		case 'e':			/* XXX set ufmt */
			needenv = 1;
			break;
#ifdef LAZY_PS
		case 'f':
			if (getuid() == 0 || getgid() == 0)
			    forceuread = 1;
			break;
#endif
		case 'G':
			add_list(&gidlist, optarg);
			xkeep_implied = 1;
			nselectors++;
			break;
#if 0
		/* XXX - This SUSv3 option is still under debate. */
		/* (it conflicts with the undocumented `-g' option) */
		case 'g':
			add_list(&pgrplist, optarg);
			xkeep_implied = 1;
			nselectors++;
			break;
#else
		case 'g':
			/* Historical BSD-ish (from SunOS) option */
			break;			/* no-op */
#endif
		case 'H':
			showthreads = KERN_PROC_INC_THREAD;
			break;
		case 'h':
			prtheader = ws.ws_row > 5 ? ws.ws_row : 22;
			break;
		case 'j':
			parsefmt(jfmt, 0);
			_fmt = 1;
			jfmt[0] = '\0';
			break;
		case 'L':
			showkey();
			exit(0);
		case 'l':
			parsefmt(lfmt, 0);
			_fmt = 1;
			lfmt[0] = '\0';
			break;
		case 'M':
			memf = optarg;
			dropgid = 1;
			break;
		case 'm':
			sortby = SORTMEM;
			break;
		case 'N':
			nlistf = optarg;
			dropgid = 1;
			break;
		case 'O':
			parsefmt(o1, 1);
			parsefmt(optarg, 1);
			parsefmt(o2, 1);
			o1[0] = o2[0] = '\0';
			_fmt = 1;
			break;
		case 'o':
			parsefmt(optarg, 1);
			_fmt = 1;
			break;
		case 'p':
			add_list(&pidlist, optarg);
			/*
			 * Note: `-p' does not *set* xkeep, but any values
			 * from pidlist are checked before xkeep is.  That
			 * way they are always matched, even if the user
			 * specifies `-X'.
			 */
			nselectors++;
			break;
#if 0
		/* XXX - This un-standard option is still under debate. */
		case 'R':
			/* This is what SUSv3 defines as the `-U' option. */
			add_list(&ruidlist, optarg);
			xkeep_implied = 1;
			nselectors++;
			break;
#endif
		case 'r':
			sortby = SORTCPU;
			break;
		case 'S':
			sumrusage = 1;
			break;
#if 0
		/* XXX - This non-standard option is still under debate. */
		/* (it conflicts with `-s' in NetBSD) */
		case 's':
			/* As seen on Solaris, Linux, IRIX. */
			add_list(&sesslist, optarg);
			xkeep_implied = 1;
			nselectors++;
			break;
#endif
		case 'T':
			if ((optarg = ttyname(STDIN_FILENO)) == NULL)
				errx(1, "stdin: not a terminal");
			/* FALLTHROUGH */
		case 't':
			add_list(&ttylist, optarg);
			xkeep_implied = 1;
			nselectors++;
			break;
		case 'U':
			/* This is what SUSv3 defines as the `-u' option. */
			add_list(&uidlist, optarg);
			xkeep_implied = 1;
			nselectors++;
			break;
		case 'u':
			parsefmt(ufmt, 0);
			sortby = SORTCPU;
			_fmt = 1;
			ufmt[0] = '\0';
			break;
		case 'v':
			parsefmt(vfmt, 0);
			sortby = SORTMEM;
			_fmt = 1;
			vfmt[0] = '\0';
			break;
		case 'w':
			if (wflag)
				termwidth = UNLIMITED;
			else if (termwidth < 131)
				termwidth = 131;
			wflag++;
			break;
		case 'X':
			/*
			 * Note that `-X' and `-x' are not standard "selector"
			 * options. For most selector-options, we check *all*
			 * processes to see if any are matched by the given
			 * value(s).  After we have a set of all the matched
			 * processes, then `-X' and `-x' govern whether we
			 * modify that *matched* set for processes which do
			 * not have a controlling terminal.  `-X' causes
			 * those processes to be deleted from the matched
			 * set, while `-x' causes them to be kept.
			 */
			xkeep = 0;
			break;
		case 'x':
			xkeep = 1;
			break;
		case 'Z':
			parsefmt(Zfmt, 0);
			Zfmt[0] = '\0';
			break;
		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (optfatal)
		exit(1);		/* Error messages already printed */

	if (xkeep < 0)			/* Neither -X nor -x was specified */
		xkeep = xkeep_implied;

#define	BACKWARD_COMPATIBILITY
#ifdef	BACKWARD_COMPATIBILITY
	if (*argv) {
		nlistf = *argv;
		if (*++argv) {
			memf = *argv;
		}
	}
#endif
	/*
	 * Discard setgid privileges if not the running kernel so that bad
	 * guys can't print interesting stuff from kernel memory.
	 */
	if (dropgid) {
		setgid(getgid());
		setuid(getuid());
	}

	kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
	if (kd == 0)
		errx(1, "%s", errbuf);

	if (!_fmt)
		parsefmt(dfmt, 0);

	if (nselectors == 0) {
		uidlist.ptr = malloc(sizeof(uid_t));
		if (uidlist.ptr == NULL)
			errx(1, "malloc failed");
		nselectors = 1;
		uidlist.count = uidlist.maxcount = 1;
		*uidlist.uids = getuid();
	}

	/*
	 * scan requested variables, noting what structures are needed,
	 * and adjusting header widths as appropriate.
	 */
	scanvars();

	/*
	 * Get process list.  If the user requested just one selector-
	 * option, then kvm_getprocs can be asked to return just those
	 * processes.  Otherwise, have it return all processes, and
	 * then this routine will search that full list and select the
	 * processes which match any of the user's selector-options.
	 */
	what = showthreads != 0 ? KERN_PROC_ALL : KERN_PROC_PROC;
	flag = 0;
	if (nselectors == 1) {
		/* XXX - Apparently there's no KERN_PROC_GID flag. */
		if (pgrplist.count == 1) {
			what = KERN_PROC_PGRP | showthreads;
			flag = *pgrplist.pids;
			nselectors = 0;
		} else if (pidlist.count == 1) {
			what = KERN_PROC_PID | showthreads;
			flag = *pidlist.pids;
			nselectors = 0;
		} else if (ruidlist.count == 1) {
			what = KERN_PROC_RUID | showthreads;
			flag = *ruidlist.uids;
			nselectors = 0;
#if 0		/* XXX - KERN_PROC_SESSION causes error in kvm_getprocs? */
		} else if (sesslist.count == 1) {
			what = KERN_PROC_SESSION | showthreads;
			flag = *sesslist.pids;
			nselectors = 0;
#endif
		} else if (ttylist.count == 1) {
			what = KERN_PROC_TTY | showthreads;
			flag = *ttylist.ttys;
			nselectors = 0;
		} else if (uidlist.count == 1) {
			what = KERN_PROC_UID | showthreads;
			flag = *uidlist.uids;
			nselectors = 0;
		} else if (all) {
			/* No need for this routine to select processes. */
			nselectors = 0;
		}
	}

	/*
	 * select procs
	 */
	nentries = -1;
	kp = kvm_getprocs(kd, what, flag, &nentries);
	if ((kp == 0 && nentries > 0) || (kp != 0 && nentries < 0))
		errx(1, "%s", kvm_geterr(kd));
	nkept = 0;
	if (nentries > 0) {
		if ((kinfo = malloc(nentries * sizeof(*kinfo))) == NULL)
			errx(1, "malloc failed");
		for (i = nentries; --i >= 0; ++kp) {
			/*
			 * If the user specified multiple selection-criteria,
			 * then keep any process matched by the inclusive OR
			 * of all the selection-criteria given.
			 */
			if (pidlist.count > 0) {
				for (elem = 0; elem < pidlist.count; elem++)
					if (kp->ki_pid == pidlist.pids[elem])
						goto keepit;
			}
			/*
			 * Note that we had to process pidlist before
			 * filtering out processes which do not have
			 * a controlling terminal.
			 */
			if (xkeep == 0) {
				if ((kp->ki_tdev == NODEV ||
				    (kp->ki_flag & P_CONTROLT) == 0))
					continue;
			}
			if (nselectors == 0)
				goto keepit;
			if (gidlist.count > 0) {
				for (elem = 0; elem < gidlist.count; elem++)
					if (kp->ki_rgid == gidlist.gids[elem])
						goto keepit;
			}
			if (pgrplist.count > 0) {
				for (elem = 0; elem < pgrplist.count; elem++)
					if (kp->ki_pgid == pgrplist.pids[elem])
						goto keepit;
			}
			if (ruidlist.count > 0) {
				for (elem = 0; elem < ruidlist.count; elem++)
					if (kp->ki_ruid == ruidlist.uids[elem])
						goto keepit;
			}
			if (sesslist.count > 0) {
				for (elem = 0; elem < sesslist.count; elem++)
					if (kp->ki_sid == sesslist.pids[elem])
						goto keepit;
			}
			if (ttylist.count > 0) {
				for (elem = 0; elem < ttylist.count; elem++)
					if (kp->ki_tdev == ttylist.ttys[elem])
						goto keepit;
			}
			if (uidlist.count > 0) {
				for (elem = 0; elem < uidlist.count; elem++)
					if (kp->ki_uid == uidlist.uids[elem])
						goto keepit;
			}
			/*
			 * This process did not match any of the user's
			 * selector-options, so skip the process.
			 */
			continue;

		keepit:
			kinfo[nkept].ki_p = kp;
			if (needuser)
				saveuser(&kinfo[nkept]);
			dynsizevars(&kinfo[nkept]);
			nkept++;
		}
	}

	sizevars();

	/*
	 * print header
	 */
	printheader();
	if (nkept == 0)
		exit(1);

	/*
	 * sort proc list
	 */
	qsort(kinfo, nkept, sizeof(KINFO), pscomp);
	/*
	 * For each process, call each variable output function.
	 */
	for (i = lineno = 0; i < nkept; i++) {
		for (vent = vhead; vent; vent = vent->next) {
			(vent->var->oproc)(&kinfo[i], vent);
			if (vent->next != NULL)
				(void)putchar(' ');
		}
		(void)putchar('\n');
		if (prtheader && lineno++ == prtheader - 4) {
			(void)putchar('\n');
			printheader();
			lineno = 0;
		}
	}
	free_list(&gidlist);
	free_list(&pidlist);
	free_list(&pgrplist);
	free_list(&ruidlist);
	free_list(&sesslist);
	free_list(&ttylist);
	free_list(&uidlist);

	exit(eval);
}

static int
addelem_gid(struct listinfo *inf, const char *elem)
{
	struct group *grp;
	const char *nameorID;
	char *endp;
	intmax_t ltemp;

	if (*elem == '\0' || strlen(elem) >= MAXLOGNAME) {
		if (*elem == '\0')
			warnx("Invalid (zero-length) %s name", inf->lname);
		else
			warnx("%s name too long: %s", inf->lname, elem);
		optfatal = 1;
		return (0);			/* Do not add this value */
	}

	/*
	 * SUSv3 states that `ps -G grouplist' should match "real-group
	 * ID numbers", and does not mention group-names.  I do want to
	 * also support group-names, so this tries for a group-id first,
	 * and only tries for a name if that doesn't work.  This is the
	 * opposite order of what is done in addelem_uid(), but in
	 * practice the order would only matter for group-names which
	 * are all-numeric.
	 */
	grp = NULL;
	nameorID = "named";
	errno = 0;
	ltemp = strtol(elem, &endp, 10);
	if (errno == 0 && *endp == '\0' && ltemp >= 0 && ltemp <= GID_MAX) {
		nameorID = "name or ID matches";
		grp = getgrgid((gid_t)ltemp);
	}
	if (grp == NULL)
		grp = getgrnam(elem);
	if (grp == NULL) {
		warnx("No %s %s '%s'", inf->lname, nameorID, elem);
		optfatal = 1;
		return (0);			/* Do not add this value */
	}

	if (inf->count >= inf->maxcount)
		expand_list(inf);
	inf->gids[(inf->count)++] = grp->gr_gid;
	return (1);
}

#define	BSD_PID_MAX	99999		/* Copy of PID_MAX from sys/proc.h */
static int
addelem_pid(struct listinfo *inf, const char *elem)
{
	char *endp;
	long tempid;

	if (*elem == '\0')
		tempid = 0L;
	else {
		errno = 0;
		tempid = strtol(elem, &endp, 10);
		if (*endp != '\0' || tempid < 0 || elem == endp) {
			warnx("Invalid %s: %s", inf->lname, elem);
			errno = ERANGE;
		} else if (errno != 0 || tempid > BSD_PID_MAX) {
			warnx("%s too large: %s", inf->lname, elem);
			errno = ERANGE;
		}
		if (errno == ERANGE) {
			optfatal = 1;
			return (0);		/* Do not add this value */
		}
	}

	if (inf->count >= inf->maxcount)
		expand_list(inf);
	inf->pids[(inf->count)++] = tempid;
	return (1);
}
#undef	BSD_PID_MAX

static int
addelem_tty(struct listinfo *inf, const char *elem)
{
	const char *ttypath;
	struct stat sb;
	char pathbuf[PATH_MAX];

	if (strcmp(elem, "co") == 0)
		ttypath = strdup(_PATH_CONSOLE);
	else if (*elem == '/')
		ttypath = elem;
	else {
		strlcpy(pathbuf, _PATH_TTY, sizeof(pathbuf));
		strlcat(pathbuf, elem, sizeof(pathbuf));
		ttypath = pathbuf;
	}

	if (stat(ttypath, &sb) == -1) {
		warn("%s", ttypath);
		optfatal = 1;
		return (0);			/* Do not add this value */
	}
	if (!S_ISCHR(sb.st_mode)) {
		warn("%s: Not a terminal", ttypath);
		optfatal = 1;
		return (0);			/* Do not add this value */
	}

	if (inf->count >= inf->maxcount)
		expand_list(inf);
	inf->ttys[(inf->count)++] = sb.st_rdev;
	return (1);
}

static int
addelem_uid(struct listinfo *inf, const char *elem)
{
	struct passwd *pwd;
	char *endp;
	intmax_t ltemp;

	if (*elem == '\0' || strlen(elem) >= MAXLOGNAME) {
		if (*elem == '\0')
			warnx("Invalid (zero-length) %s name", inf->lname);
		else
			warnx("%s name too long: %s", inf->lname, elem);
		optfatal = 1;
		return (0);			/* Do not add this value */
	}

	pwd = getpwnam(elem);
	if (pwd == NULL) {
		errno = 0;
		ltemp = strtol(elem, &endp, 10);
		if (errno != 0 || *endp != '\0' || ltemp < 0 ||
		    ltemp > UID_MAX)
			warnx("No %s named '%s'", inf->lname, elem);
		else {
			/* The string is all digits, so it might be a userID. */
			pwd = getpwuid((uid_t)ltemp);
			if (pwd == NULL)
				warnx("No %s name or ID matches '%s'",
				    inf->lname, elem);
		}
	}
	if (pwd == NULL) {
		/*
		 * These used to be treated as minor warnings (and the
		 * option was simply ignored), but now they are fatal
		 * errors (and the command will be aborted).
		 */
		optfatal = 1;
		return (0);			/* Do not add this value */
	}

	if (inf->count >= inf->maxcount)
		expand_list(inf);
	inf->uids[(inf->count)++] = pwd->pw_uid;
	return (1);
}

static void
add_list(struct listinfo *inf, const char *argp)
{
	const char *savep;
	char *cp, *endp;
	int toolong;
	char elemcopy[PATH_MAX];

	while (*argp != '\0') {
		while (*argp != '\0' && strchr(W_SEP, *argp) != NULL)
			argp++;
		savep = argp;
		toolong = 0;
		cp = elemcopy;
		if (strchr(T_SEP, *argp) == NULL) {
			endp = elemcopy + sizeof(elemcopy) - 1;
			while (*argp != '\0' && cp <= endp &&
			    strchr(W_SEP T_SEP, *argp) == NULL)
				*cp++ = *argp++;
			if (cp > endp)
				toolong = 1;
		}
		if (!toolong) {
			*cp = '\0';
#ifndef ADD_PS_LISTRESET
	/* This is how the standard expects lists to be handled. */
			inf->addelem(inf, elemcopy);
#else
	/*
	 * This would add a simple non-standard-but-convienent feature.
	 *
	 * XXX - Adding this check increased the total size of `ps' by
	 *	3940 bytes on i386!  That's 12% of the entire program!
	 *	The `ps.o' file grew by only about 40 bytes, but the
	 *	final (stripped) executable in /bin/ps grew by 12%.
	 */
			/*
			 * We now have a single element.  Add it to the
			 * list, unless the element is ":".  In that case,
			 * reset the list so previous entries are ignored.
			 */
			if (strcmp(elemcopy, ":") == 0)
				inf->count = 0;
			else
				inf->addelem(inf, elemcopy);
#endif
		} else {
			/*
			 * The string is too long to copy.  Find the end
			 * of the string to print out the warning message.
			 */
			while (*argp != '\0' && strchr(W_SEP T_SEP,
			    *argp) == NULL)
				argp++;
			warnx("Value too long: %.*s", (int)(argp - savep),
			    savep);
			optfatal = 1;
		}
		/*
		 * Skip over any number of trailing whitespace characters,
		 * but only one (at most) trailing element-terminating
		 * character.
		 */
		while (*argp != '\0' && strchr(W_SEP, *argp) != NULL)
			argp++;
		if (*argp != '\0' && strchr(T_SEP, *argp) != NULL) {
			argp++;
			/* Catch case where string ended with a comma. */
			if (*argp == '\0')
				inf->addelem(inf, argp);
		}
	}
}

static void *
expand_list(struct listinfo *inf)
{
	void *newlist;
	int newmax;

	newmax = (inf->maxcount + 1) << 1;
	newlist = realloc(inf->ptr, newmax * inf->elemsize);
	if (newlist == NULL) {
		free(inf->ptr);
		errx(1, "realloc to %d %ss failed", newmax,
		    inf->lname);
	}
	inf->maxcount = newmax;
	inf->ptr = newlist;

	return (newlist);
}

static void
free_list(struct listinfo *inf)
{

	inf->count = inf->elemsize = inf->maxcount = 0;
	if (inf->ptr != NULL)
		free(inf->ptr);
	inf->addelem = NULL;
	inf->lname = NULL;
	inf->ptr = NULL;
}

static void
init_list(struct listinfo *inf, addelem_rtn artn, int elemsize,
    const char *lname)
{

	inf->count = inf->maxcount = 0;
	inf->elemsize = elemsize;
	inf->addelem = artn;
	inf->lname = lname;
	inf->ptr = NULL;
}

VARENT *
find_varentry(VAR *v)
{
	struct varent *vent;

	for (vent = vhead; vent; vent = vent->next) {
		if (strcmp(vent->var->name, v->name) == 0)
			return vent;
	}
	return NULL;
}

static void
scanvars(void)
{
	struct varent *vent;
	VAR *v;

	for (vent = vhead; vent; vent = vent->next) {
		v = vent->var;
		if (v->flag & DSIZ) {
			v->dwidth = v->width;
			v->width = 0;
		}
		if (v->flag & USER)
			needuser = 1;
		if (v->flag & COMM)
			needcomm = 1;
	}
}

static void
dynsizevars(KINFO *ki)
{
	struct varent *vent;
	VAR *v;
	int i;

	for (vent = vhead; vent; vent = vent->next) {
		v = vent->var;
		if (!(v->flag & DSIZ))
			continue;
		i = (v->sproc)( ki);
		if (v->width < i)
			v->width = i;
		if (v->width > v->dwidth)
			v->width = v->dwidth;
	}
}

static void
sizevars(void)
{
	struct varent *vent;
	VAR *v;
	int i;

	for (vent = vhead; vent; vent = vent->next) {
		v = vent->var;
		i = strlen(vent->header);
		if (v->width < i)
			v->width = i;
		totwidth += v->width + 1;	/* +1 for space */
	}
	totwidth--;
}

static const char *
fmt(char **(*fn)(kvm_t *, const struct kinfo_proc *, int), KINFO *ki,
  char *comm, int maxlen)
{
	const char *s;

	s = fmt_argv((*fn)(kd, ki->ki_p, termwidth), comm, maxlen);
	return (s);
}

#define UREADOK(ki)	(forceuread || (ki->ki_p->ki_sflag & PS_INMEM))

static void
saveuser(KINFO *ki)
{

	if (ki->ki_p->ki_sflag & PS_INMEM) {
		/*
		 * The u-area might be swapped out, and we can't get
		 * at it because we have a crashdump and no swap.
		 * If it's here fill in these fields, otherwise, just
		 * leave them 0.
		 */
		ki->ki_valid = 1;
	} else
		ki->ki_valid = 0;
	/*
	 * save arguments if needed
	 */
	if (needcomm && (UREADOK(ki) || (ki->ki_p->ki_args != NULL))) {
		ki->ki_args = strdup(fmt(kvm_getargv, ki, ki->ki_p->ki_comm,
		    MAXCOMLEN));
	} else if (needcomm) {
		asprintf(&ki->ki_args, "(%s)", ki->ki_p->ki_comm);
	} else {
		ki->ki_args = NULL;
	}
	if (needenv && UREADOK(ki)) {
		ki->ki_env = strdup(fmt(kvm_getenvv, ki, (char *)NULL, 0));
	} else if (needenv) {
		ki->ki_env = malloc(3);
		strcpy(ki->ki_env, "()");
	} else {
		ki->ki_env = NULL;
	}
}

static int
pscomp(const void *a, const void *b)
{
	int i;
#define VSIZE(k) ((k)->ki_p->ki_dsize + (k)->ki_p->ki_ssize + \
		  (k)->ki_p->ki_tsize)

	if (sortby == SORTCPU)
		return (getpcpu((const KINFO *)b) - getpcpu((const KINFO *)a));
	if (sortby == SORTMEM)
		return (VSIZE((const KINFO *)b) - VSIZE((const KINFO *)a));
	i =  (int)((const KINFO *)a)->ki_p->ki_tdev -
	    (int)((const KINFO *)b)->ki_p->ki_tdev;
	if (i == 0)
		i = ((const KINFO *)a)->ki_p->ki_pid -
		    ((const KINFO *)b)->ki_p->ki_pid;
	return (i);
}

/*
 * ICK (all for getopt), would rather hide the ugliness
 * here than taint the main code.
 *
 *  ps foo -> ps -foo
 *  ps 34 -> ps -p34
 *
 * The old convention that 't' with no trailing tty arg means the users
 * tty, is only supported if argv[1] doesn't begin with a '-'.  This same
 * feature is available with the option 'T', which takes no argument.
 */
static char *
kludge_oldps_options(char *s)
{
	int have_fmt;
	size_t len;
	char *newopts, *ns, *cp;

	/*
	 * If we have an 'o' option, then note it, since we don't want to do
	 * some types of munging.
	 */
	have_fmt = index(s, 'o') != NULL;

	len = strlen(s);
	if ((newopts = ns = malloc(len + 2)) == NULL)
		errx(1, "malloc failed");
	/*
	 * options begin with '-'
	 */
	if (*s != '-')
		*ns++ = '-';	/* add option flag */
	/*
	 * gaze to end of argv[1]
	 */
	cp = s + len - 1;
	/*
	 * if last letter is a 't' flag with no argument (in the context
	 * of the oldps options -- option string NOT starting with a '-' --
	 * then convert to 'T' (meaning *this* terminal, i.e. ttyname(0)).
	 *
	 * However, if a flag accepting a string argument is found in the
	 * option string, the remainder of the string is the argument to
	 * that flag; do not modify that argument.
	 */
	if (strcspn(s, "MNOoU") == len && *cp == 't' && *s != '-')
		*cp = 'T';
	else {
		/*
		 * otherwise check for trailing number, which *may* be a
		 * pid.
		 */
		while (cp >= s && isdigit(*cp))
			--cp;
	}
	cp++;
	memmove(ns, s, (size_t)(cp - s));	/* copy up to trailing number */
	ns += cp - s;
	/*
	 * if there's a trailing number, and not a preceding 'p' (pid) or
	 * 't' (tty) flag, then assume it's a pid and insert a 'p' flag.
	 */
	if (isdigit(*cp) &&
	    (cp == s || (cp[-1] != 't' && cp[-1] != 'p')) &&
	    (cp - 1 == s || cp[-2] != 't') && !have_fmt)
		*ns++ = 'p';
	(void)strcpy(ns, cp);		/* and append the number */

	return (newopts);
}

static void
usage(void)
{
#define	SINGLE_OPTS	"[-aC" OPT_LAZY_f "HhjlmrSTuvwXxZ]"

	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
	    "usage: ps " SINGLE_OPTS " [-G gid[,gid]] [-O|o fmt]",
	    "          [-p pid[,pid]] [-t tty[,tty]] [-U user[,user]]",
	    "          [-M core] [-N system]",
	    "       ps [-L]");
	exit(1);
}