X-Git-Url: https://git.xinqibao.xyz/slock.git/blobdiff_plain/a6dc051e3744ce5b14c54d2d246d3e8258207e76..65b8d5278882310eed758e6fbfd6ab9676db883c:/slock.c

diff --git a/slock.c b/slock.c
index 4531f95..c9cdee2 100644
--- a/slock.c
+++ b/slock.c
@@ -52,6 +52,7 @@ die(const char *errstr, ...)
 {
 	va_list ap;
 
+	fputs("slock: ", stderr);
 	va_start(ap, errstr);
 	vfprintf(stderr, errstr, ap);
 	va_end(ap);
@@ -88,9 +89,9 @@ getpw(void)
 	errno = 0;
 	if (!(pw = getpwuid(getuid()))) {
 		if (errno)
-			die("slock: getpwuid: %s\n", strerror(errno));
+			die("getpwuid: %s\n", strerror(errno));
 		else
-			die("slock: cannot retrieve password entry\n");
+			die("cannot retrieve password entry\n");
 	}
 	rval = pw->pw_passwd;
 
@@ -98,7 +99,7 @@ getpw(void)
 	if (rval[0] == 'x' && rval[1] == '\0') {
 		struct spwd *sp;
 		if (!(sp = getspnam(getenv("USER"))))
-			die("slock: cannot retrieve shadow entry (make sure to suid or sgid slock)\n");
+			die("cannot retrieve shadow entry (make sure to suid or sgid slock)\n");
 		rval = sp->sp_pwdp;
 	}
 #endif
@@ -106,7 +107,7 @@ getpw(void)
 	/* drop privileges */
 	if (geteuid() == 0 &&
 	    ((getegid() != pw->pw_gid && setgid(pw->pw_gid) < 0) || setuid(pw->pw_uid) < 0))
-		die("slock: cannot drop privileges\n");
+		die("cannot drop privileges\n");
 	return rval;
 }
 #endif
@@ -272,33 +273,46 @@ lockscreen(Display *dpy, int screen)
 	return NULL;
 }
 
-int
-main(int argc, char **argv)
+static void
+usage(void)
 {
+	fprintf(stderr, "usage: slock [-v|POST_LOCK_CMD]\n");
+	exit(1);
+}
+
+int
+main(int argc, char **argv) {
 #ifndef HAVE_BSD_AUTH
 	const char *pws;
 #endif
 	Display *dpy;
 	int screen;
 
+	if ((argc >= 2) && !strcmp("-v", argv[1]))
+		die("version %s, © 2006-2016 slock engineers\n", VERSION);
+
+	/* treat first argument starting with a '-' as option */
+	if ((argc >= 2) && argv[1][0] == '-')
+		usage();
+
 #ifdef __linux__
 	dontkillme();
 #endif
 
 	if (!getpwuid(getuid()))
-		die("slock: no passwd entry for you\n");
+		die("no passwd entry for you\n");
 
 #ifndef HAVE_BSD_AUTH
 	pws = getpw();
 #endif
 
 	if (!(dpy = XOpenDisplay(0)))
-		die("slock: cannot open display\n");
+		die("cannot open display\n");
 	rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
 	/* Get the number of screens in display "dpy" and blank them all. */
 	nscreens = ScreenCount(dpy);
 	if (!(locks = malloc(sizeof(Lock*) * nscreens)))
-		die("slock: malloc: %s\n", strerror(errno));
+		die("Out of memory.\n");
 	int nlocks = 0;
 	for (screen = 0; screen < nscreens; screen++) {
 		if ((locks[screen] = lockscreen(dpy, screen)) != NULL)
@@ -317,7 +331,7 @@ main(int argc, char **argv)
 		if (dpy)
 			close(ConnectionNumber(dpy));
 		execvp(argv[1], argv+1);
-		die("slock: execvp %s failed: %s\n", argv[1], strerror(errno));
+		die("execvp %s failed: %s\n", argv[1], strerror(errno));
 	}
 
 	/* Everything is now blank. Now wait for the correct password. */