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Languguage OS 2
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Languguage OS II Version 10-94 (Knowledge Media)(1994).ISO
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shllutil.lha
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shellutils-1.8
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src
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who.c
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1992-10-28
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/* 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);
}