tchrist@convex.COM (Tom Christiansen) (05/22/91)
From the keyboard of tpm-sprl!tpm@uunet.uu.net (Terence P. Ma):
:I know that the last login date is in /var/adm/lastlog. Is there an easy
:way to get the lastlogin date and time of all users or groups of users
:without using "finger -s user1 user2 ..." to get at it?
Here's a C program to do that. Perl version (runs 3x slower; sigh)
available upon request.
--tom
/*
* lastlog - print last login time for all users, based on times
* stored in /usr/adm/lastlog.
*
* Lines are printed oldest first, with name, date/time, and gecos
* field on each line.
*
* No command line options. Runs on VAX/4.2 BSD Unix.
*
* compile with: cc -O -o lastlog lastlog.c
*
* Rex Sanders, US Geological Survey, Pacific Marine Geology, 12/19/85
*/
#include <stdio.h>
#include <strings.h>
#include <sys/file.h>
#include <sys/types.h>
#include <lastlog.h>
#include <pwd.h>
#include <sysexits.h>
/* maximum number of users/entries in /etc/passwd */
#define MAXU 5000
/* maximum length of the gecos field in /etc/passwd */
#define MAXG 100
char *ctime ();
long lseek ();
struct info_s {
int time;
char name[9];
char gecos[MAXG];
};
struct info_s info[MAXU];
main (argc, argv) char **argv; {
int infocmp ();
struct lastlog ll;
struct passwd *pw;
char lastdate[25];
int llfd;
register int nusers = 0;
register int i;
if ((llfd = open ("/usr/adm/lastlog", O_RDONLY)) < 0) {
perror ("lastlog: /usr/adm/lastlog");
exit (EX_OSFILE);
}
/*
* For each user in password file, grab password info
*/
while (pw = getpwent ()) {
/*
* Grab info from lastlog file
*/
if (!strcmp(pw->pw_passwd,"*"))
continue;
if (lseek (llfd, (long) pw -> pw_uid * sizeof ll, 0) == -1) {
fprintf(stderr,"%s: lseek for uid %d failed\n", *argv, pw->pw_uid);
continue;
}
if (read (llfd, (char *) & ll, sizeof ll) != sizeof ll) {
fprintf(stderr, "%s: read for uid %d failed\n", *argv, pw->pw_uid);
continue;
}
info[nusers].time = ll.ll_time;
strncpy (info[nusers].name, pw -> pw_name, 9);
strncpy (info[nusers].gecos, pw -> pw_gecos, MAXG);
if (nusers++ == MAXU) {
fprintf(stderr, "%s: recompile with MAXU > %d\n",
*argv, MAXU);
exit(EX_SOFTWARE);
}
}
/*
* Sort users by last login time
*/
qsort ((char *) info, nusers, sizeof (struct info_s), infocmp);
/*
* Print info for each user
*/
for (i = 0; i < nusers; i++) {
if (info[i].time) {
strncpy (lastdate, ctime (&info[i].time), 24);
lastdate[24] = '\0';
}
else
strcpy (lastdate, "never logged in");
printf ("%-8s %-24s %s\n", info[i].name, lastdate,
info[i].gecos);
}
close (llfd);
endpwent ();
}
/*
* infocmp - compare 2 info entries for qsort
*/
infocmp (info1, info2)
struct info_s *info1,
*info2;
{
register int r;
if (info1 -> time == info2 -> time)
r = 0;
else
r = (info1 -> time > info2 -> time) ? 1 : -1;
return (r);
}
--
Tom Christiansen tchrist@convex.com convex!tchrist
"So much mail, so little time."