Alphabetically sort the output of lastlogin(8).

According to the manpage, the entries have to be sorted by uid. This is
no longer possible, since our utmpx implementation is completely unaware
of user IDs. You can safely add entries for multiple users sharing the
same uid.

Make the output less random by sorting everything by name.

2 files changed, 22 insertions, 4 deletions

diff --git a/usr.sbin/lastlogin/lastlogin.8 b/usr.sbin/lastlogin/lastlogin.8
index 4d07a2bd249c..063016399e77 100644
--- a/usr.sbin/lastlogin/lastlogin.8
+++ b/usr.sbin/lastlogin/lastlogin.8
@@ -55,7 +55,7 @@ If more than one
 is given, the session information for each user is printed in
 the order given on the command line.
 Otherwise, information
-for all users is printed, sorted by uid.
+for all users is printed, sorted by name.
 .Pp
 The
 .Nm
diff --git a/usr.sbin/lastlogin/lastlogin.c b/usr.sbin/lastlogin/lastlogin.c
index ae3ba996f269..9c3d433cc6be 100644
--- a/usr.sbin/lastlogin/lastlogin.c
+++ b/usr.sbin/lastlogin/lastlogin.c
@@ -39,6 +39,7 @@ __RCSID("$NetBSD: lastlogin.c,v 1.4 1998/02/03 04:45:35 perry Exp $");
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <time.h>
 #include <unistd.h>
 #include <utmpx.h>
@@ -47,11 +48,19 @@ __RCSID("$NetBSD: lastlogin.c,v 1.4 1998/02/03 04:45:35 perry Exp $");
 static	void	output(struct utmpx *);
 static	void	usage(void);
 
+static int
+utcmp(const void *u1, const void *u2)
+{
+
+	return (strcmp(((const struct utmpx *)u1)->ut_user,
+	    ((const struct utmpx *)u2)->ut_user));
+}
+
 int
 main(int argc, char *argv[])
 {
-	int	ch, i;
-	struct utmpx *u;
+	int	ch, i, ulistsize;
+	struct utmpx *u, *ulist;
 
 	while ((ch = getopt(argc, argv, "")) != -1) {
 		usage();
@@ -74,12 +83,21 @@ main(int argc, char *argv[])
 	else {
 		if (setutxdb(UTXDB_LASTLOGIN, NULL) != 0)
 			errx(1, "failed to open lastlog database");
+		ulist = NULL;
+		ulistsize = 0;
 		while ((u = getutxent()) != NULL) {
 			if (u->ut_type != USER_PROCESS)
 				continue;
-			output(u);
+			if ((ulistsize % 16) == 0)
+				ulist = realloc(ulist,
+				    (ulistsize + 16) * sizeof(struct utmpx));
+			ulist[ulistsize++] = *u;
 		}
 		endutxent();
+
+		qsort(ulist, ulistsize, sizeof(struct utmpx), utcmp);
+		for (i = 0; i < ulistsize; i++)
+			output(&ulist[i]);
 	}
 
 	exit(0);