lslogins: fix -l -g logic

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

diff --git a/login-utils/lslogins.c b/login-utils/lslogins.c
index abce949c16f44019e033b056781092c58455860e..9929b147507666787ca1a4941beac332560fd2c1 100644 (file)
--- a/login-utils/lslogins.c
+++ b/login-utils/lslogins.c
@@ -266,6 +266,7 @@ struct lslogins_control {
        const char *journal_path;
 
        unsigned int selinux_enabled : 1,
+                    ulist_on : 1,
                     noheadings : 1,
                     notrunc : 1;
 };
@@ -770,41 +771,49 @@ static int get_ulist(struct lslogins_control *ctl, char *logins, char *groups)
        *arsiz = 32;
        *ar = xcalloc(1, sizeof(char *) * (*arsiz));
 
-       while ((u = strtok(logins, ","))) {
-               logins = NULL;
+       if (logins) {
+               while ((u = strtok(logins, ","))) {
+                       logins = NULL;
 
-               /* user specified by UID? */
-               if (!str_to_uint(u, &uid)) {
-                       pwd = getpwuid(uid);
-                       if (!pwd)
-                               continue;
-                       u = pwd->pw_name;
-               }
-               (*ar)[i++] = xstrdup(u);
+                       /* user specified by UID? */
+                       if (!str_to_uint(u, &uid)) {
+                               pwd = getpwuid(uid);
+                               if (!pwd)
+                                       continue;
+                               u = pwd->pw_name;
+                       }
+                       (*ar)[i++] = xstrdup(u);
 
-               if (i == *arsiz)
-                       *ar = xrealloc(*ar, sizeof(char *) * (*arsiz += 32));
+                       if (i == *arsiz)
+                               *ar = xrealloc(*ar, sizeof(char *) * (*arsiz += 32));
+               }
+               ctl->ulist_on = 1;
        }
-       /* FIXME: this might lead to duplicit entries, although not visible
-        * in output, crunching a user's info multiple times is very redundant */
-       while ((g = strtok(groups, ","))) {
-               groups = NULL;
-
-               /* user specified by GID? */
-               if (!str_to_uint(g, &gid))
-                       grp = getgrgid(gid);
-               else
-                       grp = getgrnam(g);
 
-               if (!grp)
-                       continue;
+       if (groups) {
+               /* FIXME: this might lead to duplicit entries, although not visible
+                * in output, crunching a user's info multiple times is very redundant */
+               while ((g = strtok(groups, ","))) {
+                       n = 0;
+                       groups = NULL;
 
-               while ((u = grp->gr_mem[n++])) {
-                       (*ar)[i++] = xstrdup(u);
+                       /* user specified by GID? */
+                       if (!str_to_uint(g, &gid))
+                               grp = getgrgid(gid);
+                       else
+                               grp = getgrnam(g);
 
-                       if (i == *arsiz)
-                               *ar = xrealloc(*ar, sizeof(char *) * (*arsiz += 32));
+                       if (!grp)
+                               continue;
+
+                       while ((u = grp->gr_mem[n++])) {
+                               (*ar)[i++] = xstrdup(u);
+
+                               if (i == *arsiz)
+                                       *ar = xrealloc(*ar, sizeof(char *) * (*arsiz += 32));
+                       }
                }
+               ctl->ulist_on = 1;
        }
        *arsiz = i;
        return 0;
@@ -860,7 +869,7 @@ static int create_usertree(struct lslogins_control *ctl)
        struct lslogins_user *user = NULL;
        size_t n = 0;
 
-       if (*ctl->ulist) {
+       if (ctl->ulist_on) {
                while (n < ctl->ulsiz) {
                        if (get_user(ctl, &user, ctl->ulist[n]))
                                return -1;
@@ -1450,7 +1459,8 @@ int main(int argc, char *argv[])
        if (require_btmp())
                parse_btmp(ctl, path_btmp);
 
-       get_ulist(ctl, logins, groups);
+       if (logins || groups)
+               get_ulist(ctl, logins, groups);
 
        if (create_usertree(ctl))
                return EXIT_FAILURE;