Let wall(1) use utmpx.

Because our implementation guarantees the strings inside struct utmpx to
be null terminated, we don't need to copy everything out, which makes
the code nicer to read.

Also set WARNS to 6 and add $FreeBSD$ to keep SVN happy.

2 files changed, 29 insertions, 28 deletions

diff --git a/usr.bin/write/Makefile b/usr.bin/write/Makefile
index 8e6454b..e34a61d 100644
--- a/usr.bin/write/Makefile
+++ b/usr.bin/write/Makefile
@@ -1,7 +1,13 @@
 #	@(#)Makefile	8.1 (Berkeley) 6/6/93
+# $FreeBSD$
 
 PROG=	write
 BINMODE=2555
 BINGRP=	tty
 
+WARNS?=	6
+
+DPADD=	${LIBULOG}
+LDADD=	-lulog
+
 .include <bsd.prog.mk>
diff --git a/usr.bin/write/write.c b/usr.bin/write/write.c
index 878c8c1..ed57cb1 100644
--- a/usr.bin/write/write.c
+++ b/usr.bin/write/write.c
@@ -62,8 +62,9 @@ __FBSDID("$FreeBSD$");
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#define	_ULOG_POSIX_NAMES
+#include <ulog.h>
 #include <unistd.h>
-#include <utmp.h>
 
 void done(int);
 void do_write(char *, char *, uid_t);
@@ -146,20 +147,17 @@ usage(void)
 int
 utmp_chk(char *user, char *tty)
 {
-	struct utmp u;
-	int ufd;
-
-	if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
-		return(0);	/* ignore error, shouldn't happen anyway */
-
-	while (read(ufd, (char *) &u, sizeof(u)) == sizeof(u))
-		if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0 &&
-		    strncmp(tty, u.ut_line, sizeof(u.ut_line)) == 0) {
-			(void)close(ufd);
+	struct utmpx lu, *u;
+
+	strncpy(lu.ut_line, tty, sizeof lu.ut_line);
+	setutxent();
+	while ((u = getutxline(&lu)) != NULL)
+		if (u->ut_type == USER_PROCESS &&
+		    strcmp(user, u->ut_user) == 0) {
+			endutxent();
 			return(0);
 		}
-
-	(void)close(ufd);
+	endutxent();
 	return(1);
 }
 
@@ -177,43 +175,40 @@ utmp_chk(char *user, char *tty)
 void
 search_utmp(char *user, char *tty, char *mytty, uid_t myuid)
 {
-	struct utmp u;
+	struct utmpx *u;
 	time_t bestatime, atime;
-	int ufd, nloggedttys, nttys, msgsok, user_is_me;
-	char atty[UT_LINESIZE + 1];
-
-	if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
-		err(1, "utmp");
+	int nloggedttys, nttys, msgsok, user_is_me;
 
 	nloggedttys = nttys = 0;
 	bestatime = 0;
 	user_is_me = 0;
-	while (read(ufd, (char *) &u, sizeof(u)) == sizeof(u))
-		if (strncmp(user, u.ut_name, sizeof(u.ut_name)) == 0) {
+
+	setutxent();
+	while ((u = getutxent()) != NULL)
+		if (u->ut_type == USER_PROCESS &&
+		    strcmp(user, u->ut_user) == 0) {
 			++nloggedttys;
-			(void)strncpy(atty, u.ut_line, UT_LINESIZE);
-			atty[UT_LINESIZE] = '\0';
-			if (term_chk(atty, &msgsok, &atime, 0))
+			if (term_chk(u->ut_line, &msgsok, &atime, 0))
 				continue;	/* bad term? skip */
 			if (myuid && !msgsok)
 				continue;	/* skip ttys with msgs off */
-			if (strcmp(atty, mytty) == 0) {
+			if (strcmp(u->ut_line, mytty) == 0) {
 				user_is_me = 1;
 				continue;	/* don't write to yourself */
 			}
 			++nttys;
 			if (atime > bestatime) {
 				bestatime = atime;
-				(void)strcpy(tty, atty);
+				(void)strlcpy(tty, u->ut_line, MAXPATHLEN);
 			}
 		}
+	endutxent();
 
-	(void)close(ufd);
 	if (nloggedttys == 0)
 		errx(1, "%s is not logged in", user);
 	if (nttys == 0) {
 		if (user_is_me) {		/* ok, so write to yourself! */
-			(void)strcpy(tty, mytty);
+			(void)strlcpy(tty, mytty, MAXPATHLEN);
 			return;
 		}
 		errx(1, "%s has messages disabled", user);