last: fix utmp.ut_time usage

The utmp.ut_time is timeval.tv_sec (time_t) or int32_t. It's more
robust not to use ctime() or time() directly.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/login-utils/last.c b/login-utils/last.c
index 13a3b24490a5aca91eecb6d54a5df82d949fbb65..0c4c0a16c9a377af6a588262ab396094d431f86b 100644 (file)
--- a/login-utils/last.c
+++ b/login-utils/last.c
@@ -160,6 +160,12 @@ main(int argc, char **argv) {
        exit(0);
 }
 
+static char *utmp_ctime(struct utmp *u)
+{
+       time_t t = (time_t) u->ut_time;
+       return ctime(&t);
+}
+
 /*
  * print_partial_line --
  *     print the first part of each output line according to specified format
@@ -168,7 +174,7 @@ static void
 print_partial_line(struct utmp *bp) {
     char *ct;
 
-    ct = ctime(&bp->ut_time);
+    ct = utmp_ctime(bp);
     printf("%-*.*s  %-*.*s ", nmax, nmax, bp->ut_name, 
           lmax, lmax, bp->ut_line);
 
@@ -208,10 +214,22 @@ wtmp(void) {
        int utl_len;
        int listnr = 0;
        int i;
-       
+
        utmpname(file);
 
-       (void)time(&utmpbuf.ut_time);
+       {
+#if defined(_HAVE_UT_TV)
+               struct timeval tv;
+               gettimeofday(&tv, NULL);
+               utmpbuf.ut_tv.tv_sec = tv.tv_sec;
+               utmpbuf.ut_tv.tv_usec = tv.tv_usec;
+#else
+               time_t t;
+               time(&t);
+               utmpbuf.ut_time = t;
+#endif
+       }
+
        (void)signal(SIGINT, onintr);
        (void)signal(SIGQUIT, onintr);
 
@@ -226,7 +244,7 @@ wtmp(void) {
        listnr = utl_len/sizeof(struct utmp);
 
        if(listnr) 
-               ct = ctime(&utl[0].ut_time);
+               ct = utmp_ctime(&utl[0]);
 
        for(i = listnr - 1; i >= 0; i--) {
                bp = utl+i;
@@ -254,7 +272,7 @@ wtmp(void) {
                    if (!bp->ut_name[0])
                        (void)strcpy(bp->ut_name, "reboot");
                    if (want(bp, NO)) {
-                       ct = ctime(&bp->ut_time);
+                       ct = utmp_ctime(bp);
                        if(bp->ut_type != LOGIN_PROCESS) {
                            print_partial_line(bp);
                            putchar('\n');
@@ -452,7 +470,7 @@ static void
 onintr(int signo) {
        char    *ct;
 
-       ct = ctime(&utmpbuf.ut_time);
+       ct = utmp_ctime(&utmpbuf);
        printf(_("\ninterrupted %10.10s %5.5s \n"), ct, ct + 11);
        if (signo == SIGINT)
                exit(1);