last: add --present option

The --present option will allow user to easily determine who where logged
in at a given time.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/login-utils/last.c b/login-utils/last.c
index 90bd932cd76a5cfec43ee93bde2619027ff957fe..08943a09e391be7e5a18ab2ec415fe3d9630c3ea 100644 (file)
--- a/login-utils/last.c
+++ b/login-utils/last.c
@@ -250,7 +250,7 @@ static int dns_lookup(char *result, int size, int useip, int32_t *a)
 /*
  *     Show one line of information on screen
  */
-static int list(struct utmp *p, time_t t, int what)
+static int list(struct utmp *p, time_t t, int what, time_t present)
 {
        time_t          secs, tmp;
        char            logintime[32];
@@ -291,6 +291,10 @@ static int list(struct utmp *p, time_t t, int what)
         *      Calculate times
         */
        tmp = (time_t)p->ut_time;
+
+       if (present && (present < tmp || 0 == t || t < present))
+               return 0;
+
        strcpy(logintime, ctime(&tmp));
        if (fulltime)
                sprintf(logouttime, "- %s", ctime(&t));
@@ -422,6 +426,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
        fputs(_(" -n, --limit <number> how many lines to show\n"), out);
        fputs(_(" -R, --nohostname     don't display the hostname field\n"), out);
        fputs(_(" -t, --until <YYYYMMDDHHMMSS>  display the state of the specified time\n"), out);
+       fputs(_(" -p, --present <YYYYMMDDHHMMSS>  display who where present at the specified time\n"), out);
        fputs(_(" -w, --fullnames      display full user and domain names\n"), out);
        fputs(_(" -x, --system         display system shutdown entries and run level changes\n"), out);
 
@@ -473,7 +478,8 @@ static time_t parsetm(char *ts)
        return tm;
 }
 
-static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until)
+static void process_wtmp_file(char *ufile, int lastb, int extended,
+                             time_t until, time_t present)
 {
        FILE *fp;               /* Filepointer of wtmp file */
 
@@ -548,7 +554,7 @@ static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until
                lastdate = ut.ut_time;
 
                if (lastb) {
-                       quit = list(&ut, ut.ut_time, R_NORMAL);
+                       quit = list(&ut, ut.ut_time, R_NORMAL, present);
                        continue;
                }
 
@@ -596,7 +602,7 @@ static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until
                case SHUTDOWN_TIME:
                        if (extended) {
                                strcpy(ut.ut_line, "system down");
-                               quit = list(&ut, lastboot, R_NORMAL);
+                               quit = list(&ut, lastboot, R_NORMAL, present);
                        }
                        lastdown = lastrch = ut.ut_time;
                        down = 1;
@@ -607,12 +613,12 @@ static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until
                                strcpy(ut.ut_line,
                                ut.ut_type == NEW_TIME ? "new time" :
                                        "old time");
-                               quit = list(&ut, lastdown, R_TIMECHANGE);
+                               quit = list(&ut, lastdown, R_TIMECHANGE, present);
                        }
                        break;
                case BOOT_TIME:
                        strcpy(ut.ut_line, "system boot");
-                       quit = list(&ut, lastdown, R_REBOOT);
+                       quit = list(&ut, lastdown, R_REBOOT, present);
                        lastboot = ut.ut_time;
                        down = 1;
                        break;
@@ -620,7 +626,7 @@ static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until
                        x = ut.ut_pid & 255;
                        if (extended) {
                                sprintf(ut.ut_line, "(to lvl %c)", x);
-                               quit = list(&ut, lastrch, R_NORMAL);
+                               quit = list(&ut, lastrch, R_NORMAL, present);
                        }
                        if (x == '0' || x == '6') {
                                lastdown = ut.ut_time;
@@ -644,7 +650,7 @@ static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until
                                        /* Show it */
                                        if (c == 0) {
                                                quit = list(&ut, p->ut.ut_time,
-                                                       R_NORMAL);
+                                                       R_NORMAL, present);
                                                c = 1;
                                        }
                                        if (p->next) p->next->prev = p->prev;
@@ -669,7 +675,7 @@ static void process_wtmp_file(char *ufile, int lastb, int extended, time_t until
                                                c = R_PHANTOM;
                                } else
                                        c = whydown;
-                               quit = list(&ut, lastboot, c);
+                               quit = list(&ut, lastboot, c, present);
                        }
                        /* FALLTHRU */
 
@@ -728,6 +734,7 @@ int main(int argc, char **argv)
        int extended = 0;       /* Lots of info. */
 
        time_t until = 0;       /* at what time to stop parsing the file */
+       time_t present = 0;     /* who where present at time_t */
 
        static const struct option long_opts[] = {
              { "limit",        required_argument, NULL, 'n' },
@@ -737,6 +744,7 @@ int main(int argc, char **argv)
              { "version",    no_argument,       NULL, 'V' },
              { "hostlast",   no_argument,       NULL, 'a' },
              { "until",      required_argument, NULL, 't' },
+             { "present",    required_argument, NULL, 'p' },
              { "system",     no_argument,       NULL, 'x' },
              { "dns",        no_argument,       NULL, 'd' },
              { "ip",         no_argument,       NULL, 'i' },
@@ -751,7 +759,7 @@ int main(int argc, char **argv)
        atexit(close_stdout);
 
        while ((c = getopt_long(argc, argv,
-                       "hVf:n:RxadFit:0123456789w", long_opts, NULL)) != -1) {
+                       "hVf:n:RxadFit:p:0123456789w", long_opts, NULL)) != -1) {
                switch(c) {
                case 'h':
                        usage(stdout);
@@ -785,6 +793,11 @@ int main(int argc, char **argv)
                case 'F':
                        fulltime++;
                        break;
+               case 'p':
+                       present = parsetm(optarg);
+                       if (present == (time_t) -1)
+                               errx(EXIT_FAILURE, _("invalid time value \"%s\""), optarg);
+                       break;
                case 't':
                        until = parsetm(optarg);
                        if (until == (time_t) -1)
@@ -823,7 +836,7 @@ int main(int argc, char **argv)
        }
 
        for (i = 0; i < altc; i++) {
-               process_wtmp_file(altv[i], lastb, extended, until);
+               process_wtmp_file(altv[i], lastb, extended, until, present);
                free(altv[i]);
        }
        free(altv);