Cleaning up who, adding -l and manpage

This commit is contained in:
David Galos 2013-08-04 19:56:34 -04:00
parent eddb6d39a5
commit fd262561a9
2 changed files with 32 additions and 16 deletions

8
who.1
View File

@ -3,11 +3,19 @@
who \- print who has logged on
.SH SYNOPSIS
.B who
.RB [ -m ]
.SH DESCRIPTION
.B who
prints a list of who has logged on, their controlling tty, and the
time at which they logged on.
.SH OPTIONS
.TP
.B \-m
only show users on current tty
.TP
.B \-l
also print LOGIN processes
.SH BUGS
.B who

38
who.c
View File

@ -1,26 +1,38 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include <time.h>
#include <utmp.h>
#include "util.h"
static void usage(void);
static void
usage(void)
{
eprintf("usage: who [-ml]\n");
}
int
main(int argc, char **argv)
{
struct utmp usr;
FILE *ufp;
time_t t;
char timebuf[sizeof "yyyy-mm-dd hh:mm"];
bool mflag = false;
char *tty, *ttmp;
int mflag = 0, lflag = 0;
time_t t;
ARGBEGIN {
case 'm':
mflag = true;
mflag = 1;
tty = ttyname(STDIN_FILENO);
if (!tty)
eprintf("who: stdin:");
if ((ttmp = strrchr(tty, '/')))
tty = ttmp+1;
break;
case 'l':
lflag = 1;
break;
default:
usage();
@ -29,15 +41,16 @@ main(int argc, char **argv)
if (argc > 0)
usage();
if (!(ufp = fopen(_PATH_UTMP, "r"))) {
eprintf("fopen:");
}
if (!(ufp = fopen(_PATH_UTMP, "r")))
eprintf("who: '%s':", _PATH_UTMP);
while(fread(&usr, sizeof(usr), 1, ufp) == 1) {
if (!*usr.ut_name || !*usr.ut_line ||
usr.ut_line[0] == '~')
continue;
if (mflag && strcmp(usr.ut_line,
strrchr(ttyname(STDIN_FILENO), '/') + 1))
if (mflag && strcmp(usr.ut_line, tty))
continue;
if (strcmp(usr.ut_name, "LOGIN") == lflag)
continue;
t = usr.ut_time;
strftime(timebuf, sizeof timebuf, "%Y-%m-%d %H:%M", localtime(&t));
@ -47,8 +60,3 @@ main(int argc, char **argv)
return 0;
}
void
usage(void)
{
eprintf("usage: who [-m]\n");
}