Reimplement the who(1) utility to add some features required by SUSv3:

-H option (show column headings),
-T (show mesg(1) state),
-m (same as "am I"),
-u (show idle time),
-q (quick mode; list names in columns).

PR:		36128
Reviewed by:	mike

2 files changed, 270 insertions, 122 deletions

diff --git a/usr.bin/who/who.1 b/usr.bin/who/who.1
index 5abded5..f656915 100644
--- a/usr.bin/who/who.1
+++ b/usr.bin/who/who.1
@@ -32,31 +32,60 @@
 .\"     @(#)who.1	8.2 (Berkeley) 12/30/93
 .\" $FreeBSD$
 .\"
-.Dd December 30, 1993
+.Dd May 8, 2002
 .Dt WHO 1
 .Os
 .Sh NAME
 .Nm who
-.Nd display who is logged in
+.Nd display who is on the system
 .Sh SYNOPSIS
 .Nm
-.Ar am I
-.Nm
+.Op Fl HmqsTu
+.Op Cm am I
 .Op Ar file
 .Sh DESCRIPTION
 The
 .Nm
-utility displays
-a list of all users currently logged on, showing for each user
-the login name,
-tty name, the date and time of login, and hostname if not local.
+utility displays information about currently logged in users.
+By default, this includes the login name, tty name, date and time of login and
+remote hostname if not local.
 .Pp
-Available options:
+The options are as follows:
+.Bl -tag -width indent
+.It Fl H
+Write column headings above the output.
+.It Fl m
+Show information about the terminal attached to standard input only.
+.It Fl q
+.Dq Quick mode Ns :
+List the names and number of logged in users in columns.
+All other command line options are ignored.
+.It Fl s
+Show the name, line and time fields only.
+This is the default.
+.It Fl T
+Indicate whether each user is accepting messages.
+One of the following characters is written:
+.Bl -tag -width x -compact
+.It +
+User is accepting messages.
+.It \&-
+User is not accepting messages.
+.It ?
+An error occurred.
+.El
+.It Fl u
+Show idle time for each user in hours and minutes as
+.Ql hh:mm ,
+.Ql \&.
+if the user has been idle less that a minute and
+.Ql old
+if the user has been idle more than 24 hours.
+.It Cm am I
+Equivalent to
+.Fl m .
+.El
 .Pp
-.Bl -tag -width file
-.It Ar \&am I
-Returns the invoker's real user name.
-.It Ar file
 By default,
 .Nm
 gathers information from the file
@@ -80,7 +109,6 @@ since
 .Pa wtmp
 was last truncated or
 created.
-.El
 .Pp
 If
 .Pa /var/log/wtmp
@@ -95,11 +123,18 @@ special characters, see
 .It Pa /var/log/wtmp
 .It Pa /var/log/wtmp.[0-6]
 .El
+.Sh DIAGNOSTICS
+.Ex -std
 .Sh SEE ALSO
 .Xr last 1 ,
 .Xr users 1 ,
-.Xr getuid 2 ,
+.Xr w 1 ,
 .Xr utmp 5
+.Sh STANDARDS
+The
+.Nm
+utility conforms to
+.St -p1003.1-2001 .
 .Sh HISTORY
 A
 .Nm
diff --git a/usr.bin/who/who.c b/usr.bin/who/who.c
index 02b5e51..6268095 100644
--- a/usr.bin/who/who.c
+++ b/usr.bin/who/who.c
@@ -1,9 +1,6 @@
-/*
- * Copyright (c) 1989, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Michael Fischbein.
+/*-
+ * Copyright (c) 2002 Tim J. Robbins.
+ * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -13,18 +10,11 @@
  * 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
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR 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)
@@ -35,25 +25,16 @@
  */
 
 #include <sys/cdefs.h>
-
 __FBSDID("$FreeBSD$");
 
-#ifndef lint
-static const char copyright[] =
-"@(#) Copyright (c) 1989, 1993\n\
-	The Regents of the University of California.  All rights reserved.\n";
-#endif
-
-#ifndef lint
-static const char sccsid[] = "@(#)who.c	8.1 (Berkeley) 6/6/93";
-#endif
-
 #include <sys/types.h>
-#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
 
 #include <err.h>
 #include <langinfo.h>
 #include <locale.h>
+#include <paths.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -62,107 +43,239 @@ static const char sccsid[] = "@(#)who.c	8.1 (Berkeley) 6/6/93";
 #include <unistd.h>
 #include <utmp.h>
 
-static void usage(void);
-static void output(struct utmp *);
-static FILE *file(const char *);
+static void	heading(void);
+static void	process_utmp(FILE *);
+static void	quick(FILE *);
+static void	row(struct utmp *);
+static int	ttywidth(void);
+static void	usage(void);
+static void	whoami(FILE *);
+
+static int	Hflag;			/* Write column headings */
+static int	mflag;			/* Show info about current terminal */
+static int	qflag;			/* "Quick" mode */
+static int	sflag;			/* Show name, line, time */
+static int	Tflag;			/* Show terminal state */
+static int	uflag;			/* Show idle time */
 
 int
-main(argc, argv)
-	int argc;
-	char **argv;
+main(int argc, char *argv[])
 {
-	char *p;
-	struct utmp usr;
-	struct passwd *pw;
-	FILE *ufp;
-	char *t;
-
-	(void) setlocale(LC_TIME, "");
-
-	switch (argc) {
-	case 1:					/* who */
-		ufp = file(_PATH_UTMP);
-		/* only entries with both name and line fields */
-		while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
-			if (*usr.ut_name && *usr.ut_line)
-				output(&usr);
-		break;
-	case 2:					/* who utmp_file */
-		ufp = file(argv[1]);
-		/* all entries */
-		while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
-			output(&usr);
-		break;
-	case 3:					/* who am i */
-	        if (strcmp(argv[1], "am")
-		    || (strcmp(argv[2], "I") && strcmp(argv[2], "i")))
-		        usage();
-		
-		ufp = file(_PATH_UTMP);
-
-		/* search through the utmp and find an entry for this tty */
-		if ((p = ttyname(0))) {
-			/* strip any directory component */
-			if ((t = rindex(p, '/')))
-				p = t + 1;
-			while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
-				if (*usr.ut_name && !strcmp(usr.ut_line, p)) {
-					output(&usr);
-					exit(0);
-				}
-			/* well, at least we know what the tty is */
-			(void)strncpy(usr.ut_line, p, UT_LINESIZE);
-		} else
-			(void)strcpy(usr.ut_line, "tty??");
-		pw = getpwuid(getuid());
-		(void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE);
-		(void)time(&usr.ut_time);
-		*usr.ut_host = '\0';
-		output(&usr);
-		break;
-	default:
+	int ch;
+	const char *file;
+	FILE *fp;
+
+	setlocale(LC_TIME, "");
+
+	while ((ch = getopt(argc, argv, "HTabdlmpqrstu")) != -1) {
+		switch (ch) {
+		case 'H':		/* Write column headings */
+			Hflag = 1;
+			break;
+		case 'T':		/* Show terminal state */
+			Tflag = 1;
+			break;
+		case 'm':		/* Show info about current terminal */
+			mflag = 1;
+			break;
+		case 'q':		/* "Quick" mode */
+			qflag = 1;
+			break;
+		case 's':		/* Show name, line, time */
+			sflag = 1;
+			break;
+		case 'u':		/* Show idle time */
+			uflag = 1;
+			break;
+		default:
+			usage();
+			/*NOTREACHED*/
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc >= 2 && strcmp(argv[0], "am") == 0 &&
+	    (strcmp(argv[1], "i") == 0 || strcmp(argv[1], "I") == 0)) {
+		/* "who am i" or "who am I", equivalent to -m */
+		mflag = 1;
+		argc -= 2;
+		argv += 2;
+	}
+	if (argc > 1)
 		usage();
+
+	if (*argv != NULL)
+		file = *argv;
+	else
+		file = _PATH_UTMP;
+	if ((fp = fopen(file, "r")) == NULL)
+		err(1, "%s", file);
+
+	if (qflag)
+		quick(fp);
+	else {
+		if (sflag)
+			Tflag = uflag = 0;
+		if (Hflag)
+			heading();
+		if (mflag)
+			whoami(fp);
+		else
+			process_utmp(fp);
 	}
+
+	fclose(fp);
+
 	exit(0);
 }
 
-static void
-usage()
+void
+usage(void)
 {
-	(void)fprintf(stderr, "%s\n%s\n",
-		"usage: who [file]",
-		"       who am i");
+
+	fprintf(stderr, "usage: who [-HmqsTu] [am I] [file]\n");
 	exit(1);
 }
 
 void
-output(up)
-	struct utmp *up;
+heading(void)
 {
-	char buf[80];
+
+	printf("%-*s ", UT_NAMESIZE, "NAME");
+	if (Tflag)
+		printf("S ");
+	printf("%-*s ", UT_LINESIZE, "LINE");
+	printf("%-*s ", 12, "TIME");
+	if (uflag)
+		printf("IDLE  ");
+	putchar('\n');
+}
+
+void
+row(struct utmp *ut)
+{
+	char buf[80], tty[sizeof(_PATH_DEV) + UT_LINESIZE];
+	struct stat sb;
+	time_t idle;
 	static int d_first = -1;
+	struct tm *tm;
+	char state;
 
 	if (d_first < 0)
 		d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
 
-	(void)printf("%-*.*s %-*.*s", UT_NAMESIZE, UT_NAMESIZE, up->ut_name,
-	    UT_LINESIZE, UT_LINESIZE, up->ut_line);
-	(void)strftime(buf, sizeof(buf),
-		       d_first ? "%e %b %R" : "%b %e %R",
-		       localtime(&up->ut_time));
-	(void)printf("%s", buf);
-	if (*up->ut_host)
-		printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host);
-	(void)putchar('\n');
+	if (Tflag || uflag) {
+		snprintf(tty, sizeof(tty), "%s%.*s", _PATH_DEV,
+			UT_LINESIZE, ut->ut_line);
+		state = '?';
+		idle = 0;
+		if (stat(tty, &sb) == 0) {
+			state = sb.st_mode & (S_IWOTH|S_IWGRP) ?
+			    '+' : '-';
+			idle = time(NULL) - sb.st_mtime;
+		}
+	}
+
+	printf("%-*.*s ", UT_NAMESIZE, UT_NAMESIZE, ut->ut_name);
+	if (Tflag)
+		printf("%c ", state);
+	printf("%-*.*s ", UT_LINESIZE, UT_LINESIZE, ut->ut_line);
+	tm = localtime(&ut->ut_time);
+	strftime(buf, sizeof(buf), d_first ? "%e %b %R" : "%b %e %R", tm);
+	printf("%-*s ", 12, buf);
+	if (uflag) {
+		if (idle < 60)
+			printf("  .   ");
+		else if (idle < 24 * 60 * 60)
+			printf("%02d:%02d ", (int)(idle / 60 / 60),
+			    (int)(idle / 60 % 60));
+		else
+			printf(" old  ");
+	}
+	if (*ut->ut_host != '\0')
+		printf("(%.*s)", UT_HOSTSIZE, ut->ut_host);
+	putchar('\n');
+}
+
+void
+process_utmp(FILE *fp)
+{
+	struct utmp ut;
+
+	while (fread(&ut, sizeof(ut), 1, fp) == 1)
+		if (*ut.ut_name != '\0')
+			row(&ut);
+}
+
+void
+quick(FILE *fp)
+{
+	struct utmp ut;
+	int col, ncols, num;
+
+	ncols = ttywidth();
+	col = num = 0;
+	while (fread(&ut, sizeof(ut), 1, fp) == 1) { 
+		if (*ut.ut_name == '\0')
+			continue;
+		printf("%-*.*s", UT_NAMESIZE, UT_NAMESIZE, ut.ut_name);
+		if (++col < ncols / (UT_NAMESIZE + 1))
+			putchar(' ');
+		else {
+			col = 0;
+			putchar('\n');
+		}
+		num++;
+	}
+	if (col != 0)
+		putchar('\n');
+
+	printf("# users = %d\n", num);
 }
 
-static FILE *
-file(name)
-	const char *name;
+void
+whoami(FILE *fp)
 {
-	FILE *ufp;
+	struct utmp ut;
+	struct passwd *pwd;
+	const char *name, *p, *tty;
+
+	if ((tty = ttyname(STDIN_FILENO)) == NULL)
+		tty = "tty??";
+	else if ((p = strrchr(tty, '/')) != NULL)
+		tty = p + 1;
+
+	/* Search utmp for our tty, dump first matching record. */
+	while (fread(&ut, sizeof(ut), 1, fp) == 1)
+		if (*ut.ut_name != '\0' && strncmp(ut.ut_line, tty,
+		    UT_LINESIZE) == 0) {
+			row(&ut);
+			return;
+		}
+
+	/* Not found; fill the utmp structure with the information we have. */
+	memset(&ut, 0, sizeof(ut));
+	if ((pwd = getpwuid(getuid())) != NULL)
+		name = pwd->pw_name;
+	else
+		name = "?";
+	strncpy(ut.ut_name, name, UT_NAMESIZE);
+	strncpy(ut.ut_line, tty, UT_LINESIZE);
+	time(&ut.ut_time);
+	row(&ut);
+}
+
+int
+ttywidth(void)
+{
+	struct winsize ws;
+	int width;
+
+	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1)
+		width = ws.ws_col;
+	else
+		width = 80;
 
-	if (!(ufp = fopen(name, "r")))
-		err(1, "%s", name);
-	return(ufp);
+	return (width);
 }