Initial revision

1 files changed, 434 insertions, 0 deletions

diff --git a/src/who.c b/src/who.c
new file mode 100644
index 000000000..d5f40dc55
--- /dev/null
+++ b/src/who.c
@@ -0,0 +1,434 @@
+/* GNU's who.
+   Copyright (C) 1992 Free Software Foundation, Inc.
+
+   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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Written by jla; revised by djm */
+
+/* Output format:
+   name [state] line time [idle] host
+   state: -T
+   name, line, time: not -q
+   idle: -u
+
+   Options:
+   -m		Same as 'who am i', for POSIX.
+   -q		Only user names and # logged on; overrides all other options.
+   -s		Name, line, time (default).
+   -i, -u	Idle hours and minutes; '.' means active in last minute;
+		'old' means idle for >24 hours.
+   -H		Print column headings at top.
+   -w, -T	-s plus mesg (+ or -, or ? if bad line). */
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <utmp.h>
+#include <time.h>
+#include <getopt.h>
+#ifndef _POSIX_SOURCE
+#include <sys/param.h>
+#endif
+#include "system.h"
+
+#ifndef UTMP_FILE
+#ifdef _PATH_UTMP		/* 4.4BSD.  */
+#define UTMP_FILE _PATH_UTMP
+#else				/* !_PATH_UTMP */
+#define UTMP_FILE "/etc/utmp"
+#endif				/* !_PATH_UTMP */
+#endif				/* !UTMP_FILE */
+
+#ifndef MAXHOSTNAMELEN
+#define MAXHOSTNAMELEN 64
+#endif
+
+#define MESG_BIT 020		/* Group write bit. */
+
+char *ttyname ();
+
+char *idle_string ();
+char *xmalloc ();
+struct utmp *search_entries ();
+void error ();
+void list_entries ();
+void print_entry ();
+void print_heading ();
+void scan_entries ();
+void usage ();
+void who ();
+void who_am_i ();
+
+/* The name this program was run with. */
+char *program_name;
+
+/* If nonzero, display only a list of usernames and count of
+   the users logged on.
+   Ignored for `who am i'. */
+int short_list;
+
+/* If nonzero, display the hours:minutes since each user has touched
+   the keyboard, or "." if within the last minute, or "old" if
+   not within the last day. */
+int include_idle;
+
+/* If nonzero, display a line at the top describing each field. */
+int include_heading;
+
+/* If nonzero, display a `+' for each user if mesg y, a `-' if mesg n,
+   or a `?' if their tty cannot be statted. */
+int include_mesg;
+
+struct option longopts[] =
+{
+  {"count", 0, NULL, 'q'},
+  {"idle", 0, NULL, 'u'},
+  {"heading", 0, NULL, 'H'},
+  {"message", 0, NULL, 'T'},
+  {"mesg", 0, NULL, 'T'},
+  {"writable", 0, NULL, 'T'},
+  {NULL, 0, NULL, 0}
+};
+
+void
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int optc, longind;
+  int my_line_only = 0;
+
+  program_name = argv[0];
+
+  while ((optc = getopt_long (argc, argv, "imqsuwHT", longopts, &longind))
+	 != EOF)
+    {
+      switch (optc)
+	{
+	case 'm':
+	  my_line_only = 1;
+	  break;
+
+	case 'q':
+	  short_list = 1;
+	  break;
+
+	case 's':
+	  break;
+
+	case 'i':
+	case 'u':
+	  include_idle = 1;
+	  break;
+
+	case 'H':
+	  include_heading = 1;
+	  break;
+
+	case 'w':
+	case 'T':
+	  include_mesg = 1;
+	  break;
+
+	default:
+	  usage ();
+	}
+    }
+
+  if (chdir ("/dev"))
+    error (1, errno, "cannot change directory to /dev");
+
+  switch (argc - optind)
+    {
+    case 0:			/* who */
+      if (my_line_only)
+	who_am_i (UTMP_FILE);
+      else
+	who (UTMP_FILE);
+      break;
+
+    case 1:			/* who <utmp file> */
+      if (my_line_only)
+	who_am_i (argv[optind]);
+      else
+	who (argv[optind]);
+      break;
+
+    case 2:			/* who <blurf> <glop> */
+      who_am_i (UTMP_FILE);
+      break;
+
+    default:			/* lose */
+      usage ();
+    }
+
+  exit (0);
+}
+
+static struct utmp *utmp_contents;
+
+/* Display a list of who is on the system, according to utmp file FILENAME. */
+
+void
+who (filename)
+     char *filename;
+{
+  int users;
+
+  users = read_utmp (filename);
+  if (short_list)
+    list_entries (users);
+  else
+    scan_entries (users);
+}
+
+/* Read the utmp file FILENAME into UTMP_CONTENTS and return the
+   number of entries it contains. */
+
+int
+read_utmp (filename)
+     char *filename;
+{
+  register int desc;
+  struct stat file_stats;
+
+  desc = open (filename, O_RDONLY, 0);
+  if (desc < 0)
+    error (1, errno, "%s", filename);
+
+  fstat (desc, &file_stats);
+  if (file_stats.st_size > 0)
+    utmp_contents = (struct utmp *) xmalloc ((unsigned) file_stats.st_size);
+  else
+    {
+      close (desc);
+      return 0;
+    }
+
+  /* Use < instead of != in case the utmp just grew.  */
+  if (read (desc, utmp_contents, file_stats.st_size) < file_stats.st_size)
+    error (1, errno, "%s", filename);
+
+  if (close (desc))
+    error (1, errno, "%s", filename);
+
+  return file_stats.st_size / sizeof (struct utmp);
+}
+
+/* Display a line of information about entry THIS. */
+
+void
+print_entry (this)
+     struct utmp *this;
+{
+  struct stat stats;
+  time_t last_change;
+  char mesg;
+  char line[sizeof (this->ut_line) + 1];
+
+  strncpy (line, this->ut_line, sizeof (this->ut_line));
+  line[sizeof (this->ut_line)] = 0;
+  if (stat (line, &stats) == 0)
+    {
+      mesg = (stats.st_mode & MESG_BIT) ? '+' : '-';
+      last_change = stats.st_atime;
+    }
+  else
+    {
+      mesg = '?';
+      last_change = 0;
+    }
+  
+  printf ("%-*.*s",
+	  sizeof (this->ut_name), sizeof (this->ut_name),
+	  this->ut_name);
+  if (include_mesg)
+    printf ("  %c  ", mesg);
+  printf (" %-*.*s",
+	  sizeof (this->ut_line), sizeof (this->ut_line),
+	  this->ut_line);
+  printf (" %-12.12s", ctime (&this->ut_time) + 4);
+  if (include_idle)
+    {
+      if (last_change)
+	printf (" %s", idle_string (last_change));
+      else
+	printf ("   .  ");
+    }
+#ifdef HAVE_UT_HOST
+  if (this->ut_host[0])
+    printf (" (%-.*s)", sizeof (this->ut_host), this->ut_host);
+#endif
+
+  putchar ('\n');
+}
+
+/* Print the username of each valid entry and the number of valid entries
+   in `utmp_contents', which should have N elements. */
+
+void
+list_entries (n)
+     int n;
+{
+  register struct utmp *this = utmp_contents;
+  register int entries = 0;
+
+  while (n--)
+    {
+      if (this->ut_name[0]
+#ifdef USER_PROCESS
+	  && this->ut_type == USER_PROCESS
+#endif
+	 )
+	{
+	  printf ("%s ", this->ut_name);
+	  entries++;
+	}
+      this++;
+    }
+  printf ("\n# users=%u\n", entries);
+}
+
+void
+print_heading ()
+{
+  struct utmp *ut;
+
+  printf ("%-*s ", sizeof (ut->ut_name), "USER");
+  if (include_mesg)
+    printf ("MESG ");
+  printf ("%-*s ", sizeof (ut->ut_line), "LINE");
+  printf ("LOGIN-TIME   ");
+  if (include_idle)
+    printf ("IDLE  ");
+  printf ("FROM\n");
+}
+
+/* Display `utmp_contents', which should have N entries. */
+
+void
+scan_entries (n)
+     int n;
+{
+  register struct utmp *this = utmp_contents;
+
+  if (include_heading)
+    print_heading ();
+
+  while (n--)
+    {
+      if (this->ut_name[0]
+#ifdef USER_PROCESS
+	  && this->ut_type == USER_PROCESS
+#endif
+	 )
+	print_entry (this);
+      this++;
+    }
+}
+
+/* Search `utmp_contents', which should have N entries, for
+   an entry with a `ut_line' field identical to LINE.
+   Return the first matching entry found, or NULL if there
+   is no matching entry. */
+
+struct utmp *
+search_entries (n, line)
+     int n;
+     char *line;
+{
+  register struct utmp *this = utmp_contents;
+
+  while (n--)
+    {
+      if (this->ut_name[0]
+#ifdef USER_PROCESS
+	  && this->ut_type == USER_PROCESS
+#endif
+	  && !strncmp (line, this->ut_line, sizeof (this->ut_line)))
+	return this;
+      this++;
+    }
+  return NULL;
+}
+
+/* Display the entry in utmp file FILENAME for this tty on standard input,
+   or nothing if there is no entry for it. */
+
+void
+who_am_i (filename)
+     char *filename;
+{
+  register struct utmp *utmp_entry;
+  char hostname[MAXHOSTNAMELEN + 1];
+  char *tty;
+
+  if (gethostname (hostname, MAXHOSTNAMELEN + 1))
+    *hostname = 0;
+
+  if (include_heading)
+    {
+      printf ("%*s ", strlen (hostname), " ");
+      print_heading ();
+    }
+
+  tty = ttyname (0);
+  if (tty == NULL)
+    return;
+  tty += 5;			/* Remove "/dev/".  */
+  
+  utmp_entry = search_entries (read_utmp (filename), tty);
+  if (utmp_entry == NULL)
+    return;
+
+  printf ("%s!", hostname);
+  print_entry (utmp_entry);
+}
+
+/* Return a string representing the time between WHEN and the time
+   that this function is first run. */
+
+char *
+idle_string (when)
+     time_t when;
+{
+  static time_t now = 0;
+  static char idle[10];
+  time_t seconds_idle;
+
+  if (now == 0)
+    time (&now);
+
+  seconds_idle = now - when;
+  if (seconds_idle < 60)	/* One minute. */
+    return "  .  ";
+  if (seconds_idle < (24 * 60 * 60)) /* One day. */
+    {
+      sprintf (idle, "%02d:%02d",
+	       seconds_idle / (60 * 60),
+	       (seconds_idle % (60 * 60)) / 60);
+      return idle;
+    }
+  return " old ";
+}
+
+void
+usage ()
+{
+  fprintf (stderr, "\
+Usage: %s [-imqsuwHT] [--count] [--idle] [--heading] [--message] [--mesg]\n\
+       [--writable] [file] [am i]\n",
+	   program_name);
+  exit (1);
+}