Use err(3). Add usage() and prototypes.

2 files changed, 60 insertions, 67 deletions

diff --git a/usr.bin/write/write.1 b/usr.bin/write/write.1
index 16cb704..a5fe52d 100644
--- a/usr.bin/write/write.1
+++ b/usr.bin/write/write.1
@@ -33,7 +33,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     @(#)write.1	8.1 (Berkeley) 6/6/93
-.\"	$Id: write.1,v 1.4 1997/02/22 19:57:53 peter Exp $
+.\"	$Id: write.1,v 1.5 1997/03/22 17:19:32 mpp Exp $
 .\"
 .Dd June 6, 1993
 .Dt WRITE 1
@@ -51,7 +51,7 @@ allows you to communicate with other users, by copying lines from
 your terminal to theirs.
 .Pp
 When you run the
-.Nm write
+.Nm
 command, the user you are writing to gets a message of the form:
 .Pp
 .Dl Message from yourname@yourhost on yourtty at hh:mm ...
@@ -59,7 +59,7 @@ command, the user you are writing to gets a message of the form:
 Any further lines you enter will be copied to the specified user's
 terminal.
 If the other user wants to reply, they must run
-.Nm write
+.Nm
 as well.
 .Pp
 When you are done, type an end-of-file or interrupt character.
@@ -76,10 +76,10 @@ command.
 If the user you want to write to is logged in on more than one terminal,
 you can specify which terminal to write to by specifying the terminal
 name as the second operand to the
-.Nm write
+.Nm
 command.
 Alternatively, you can let
-.Nm write
+.Nm
 select one of the terminals \- it will pick the one with the shortest
 idle time.
 This is so that if the user is logged in at work and also dialed up from
diff --git a/usr.bin/write/write.c b/usr.bin/write/write.c
index dd0248d..c05ab62 100644
--- a/usr.bin/write/write.c
+++ b/usr.bin/write/write.c
@@ -35,13 +35,17 @@
  */
 
 #ifndef lint
-static char copyright[] =
+static const char copyright[] =
 "@(#) Copyright (c) 1989, 1993\n\
 	The Regents of the University of California.  All rights reserved.\n";
 #endif /* not lint */
 
 #ifndef lint
+#if 0
 static char sccsid[] = "@(#)write.c	8.1 (Berkeley) 6/6/93";
+#endif
+static const char rcsid[] =
+	"$Id$";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -49,15 +53,24 @@ static char sccsid[] = "@(#)write.c	8.1 (Berkeley) 6/6/93";
 #include <sys/stat.h>
 #include <sys/file.h>
 #include <sys/time.h>
-#include <utmp.h>
 #include <ctype.h>
+#include <err.h>
 #include <paths.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>
+#include <utmp.h>
 
-extern int errno;
+void done __P((void));
+void do_write __P((char *, char *, uid_t));
+static void usage __P((void));
+int term_chk __P((char *, int *, time_t *, int));
+void wr_fputs __P((unsigned char *s));
+void search_utmp __P((char *, char *, char *, uid_t));
+int utmp_chk __P((char *, char *));
 
+int
 main(argc, argv)
 	int argc;
 	char **argv;
@@ -66,8 +79,7 @@ main(argc, argv)
 	time_t atime;
 	uid_t myuid;
 	int msgsok, myttyfd;
-	char tty[MAXPATHLEN], *mytty, *ttyname();
-	void done();
+	char tty[MAXPATHLEN], *mytty;
 
 	/* check that sender has write enabled */
 	if (isatty(fileno(stdin)))
@@ -76,23 +88,16 @@ main(argc, argv)
 		myttyfd = fileno(stdout);
 	else if (isatty(fileno(stderr)))
 		myttyfd = fileno(stderr);
-	else {
-		(void)fprintf(stderr, "write: can't find your tty\n");
-		exit(1);
-	}
-	if (!(mytty = ttyname(myttyfd))) {
-		(void)fprintf(stderr, "write: can't find your tty's name\n");
-		exit(1);
-	}
-	if (cp = rindex(mytty, '/'))
+	else
+		errx(1, "can't find your tty");
+	if (!(mytty = ttyname(myttyfd)))
+		errx(1, "can't find your tty's name");
+	if ((cp = rindex(mytty, '/')))
 		mytty = cp + 1;
 	if (term_chk(mytty, &msgsok, &atime, 1))
 		exit(1);
-	if (!msgsok) {
-		(void)fprintf(stderr,
-		    "write: you have write permission turned off.\n");
-		exit(1);
-	}
+	if (!msgsok)
+		errx(1, "you have write permission turned off");
 
 	myuid = getuid();
 
@@ -105,34 +110,33 @@ main(argc, argv)
 	case 3:
 		if (!strncmp(argv[2], _PATH_DEV, strlen(_PATH_DEV)))
 			argv[2] += strlen(_PATH_DEV);
-		if (utmp_chk(argv[1], argv[2])) {
-			(void)fprintf(stderr,
-			    "write: %s is not logged in on %s.\n",
-			    argv[1], argv[2]);
-			exit(1);
-		}
+		if (utmp_chk(argv[1], argv[2]))
+			errx(1, "%s is not logged in on %s", argv[1], argv[2]);
 		if (term_chk(argv[2], &msgsok, &atime, 1))
 			exit(1);
-		if (myuid && !msgsok) {
-			(void)fprintf(stderr,
-			    "write: %s has messages disabled on %s\n",
-			    argv[1], argv[2]);
-			exit(1);
-		}
+		if (myuid && !msgsok)
+			errx(1, "%s has messages disabled on %s", argv[1], argv[2]);
 		do_write(argv[2], mytty, myuid);
 		break;
 	default:
-		(void)fprintf(stderr, "usage: write user [tty]\n");
-		exit(1);
+		usage();
 	}
 	done();
-	/* NOTREACHED */
+	return (0);
+}
+
+static void
+usage()
+{
+	(void)fprintf(stderr, "usage: write user [tty]\n");
+	exit(1);
 }
 
 /*
  * utmp_chk - checks that the given user is actually logged in on
  *     the given tty
  */
+int
 utmp_chk(user, tty)
 	char *user, *tty;
 {
@@ -164,6 +168,7 @@ utmp_chk(user, tty)
  * Special case for writing to yourself - ignore the terminal you're
  * writing from, unless that's the only terminal with messages enabled.
  */
+void
 search_utmp(user, tty, mytty, myuid)
 	char *user, *tty, *mytty;
 	uid_t myuid;
@@ -173,10 +178,8 @@ search_utmp(user, tty, mytty, myuid)
 	int ufd, nloggedttys, nttys, msgsok, user_is_me;
 	char atty[UT_LINESIZE + 1];
 
-	if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0) {
-		perror("utmp");
-		exit(1);
-	}
+	if ((ufd = open(_PATH_UTMP, O_RDONLY)) < 0)
+		err(1, "utmp");
 
 	nloggedttys = nttys = 0;
 	bestatime = 0;
@@ -202,22 +205,16 @@ search_utmp(user, tty, mytty, myuid)
 		}
 
 	(void)close(ufd);
-	if (nloggedttys == 0) {
-		(void)fprintf(stderr, "write: %s is not logged in\n", user);
-		exit(1);
-	}
+	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);
 			return;
 		}
-		(void)fprintf(stderr,
-		    "write: %s has messages disabled\n", user);
-		exit(1);
+		errx(1, "%s has messages disabled", user);
 	} else if (nttys > 1) {
-		(void)fprintf(stderr,
-		    "write: %s is logged in more than once; writing to %s\n",
-		    user, tty);
+		warnx("%s is logged in more than once; writing to %s", user, tty);
 	}
 }
 
@@ -225,6 +222,7 @@ search_utmp(user, tty, mytty, myuid)
  * term_chk - check that a terminal exists, and get the message bit
  *     and the access time
  */
+int
 term_chk(tty, msgsokP, atimeP, showerror)
 	char *tty;
 	int *msgsokP, showerror;
@@ -236,8 +234,7 @@ term_chk(tty, msgsokP, atimeP, showerror)
 	(void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty);
 	if (stat(path, &s) < 0) {
 		if (showerror)
-			(void)fprintf(stderr,
-			    "write: %s: %s\n", path, strerror(errno));
+			warn("%s", path);
 		return(1);
 	}
 	*msgsokP = (s.st_mode & (S_IWRITE >> 3)) != 0;	/* group write bit */
@@ -248,28 +245,26 @@ term_chk(tty, msgsokP, atimeP, showerror)
 /*
  * do_write - actually make the connection
  */
+void
 do_write(tty, mytty, myuid)
 	char *tty, *mytty;
 	uid_t myuid;
 {
 	register char *login, *nows;
 	register struct passwd *pwd;
-	time_t now, time();
-	char *getlogin(), path[MAXPATHLEN], host[MAXHOSTNAMELEN], line[512];
-	void done();
+	time_t now;
+	char path[MAXPATHLEN], host[MAXHOSTNAMELEN], line[512];
 
 	/* Determine our login name before the we reopen() stdout */
 	if ((login = getlogin()) == NULL)
-		if (pwd = getpwuid(myuid))
+		if ((pwd = getpwuid(myuid)))
 			login = pwd->pw_name;
 		else
 			login = "???";
 
 	(void)snprintf(path, sizeof(path), "%s%s", _PATH_DEV, tty);
-	if ((freopen(path, "w", stdout)) == NULL) {
-		(void)fprintf(stderr, "write: %s: %s\n", path, strerror(errno));
-		exit(1);
-	}
+	if ((freopen(path, "w", stdout)) == NULL)
+		err(1, "%s", path);
 
 	(void)signal(SIGINT, done);
 	(void)signal(SIGHUP, done);
@@ -301,11 +296,12 @@ done()
  * wr_fputs - like fputs(), but makes control characters visible and
  *     turns \n into \r\n
  */
+void
 wr_fputs(s)
 	register unsigned char *s;
 {
 
-#define	PUTC(c)	if (putchar(c) == EOF) goto err;
+#define	PUTC(c)	if (putchar(c) == EOF) err(1, NULL);
 
 	for (; *s != '\0'; ++s) {
 		if (*s == '\n') {
@@ -324,8 +320,5 @@ wr_fputs(s)
 		PUTC(*s);
 	}
 	return;
-
-err:	(void)fprintf(stderr, "write: %s\n", strerror(errno));
-	exit(1);
 #undef PUTC
 }