xscreenshot

commit bcf725e82616a2ff64e4cc70c529c185440df14d
parent c776bb923767e4ca1fa1e6179cfc37e3d0babc0a
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Mon, 16 Nov 2015 22:04:24 +0100

xscreenshot: descriptive error message on invalid winid

Diffstat:
M
xscreenshot.c
 | 
12
+++++++++---

1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/xscreenshot.c b/xscreenshot.c
@@ -35,6 +35,7 @@ main(int argc, char *argv[])
 	XWindowAttributes attr;
 	uint32_t tmp, w, h;
 	uint16_t rgba[4];
+	char *ep;
 
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("Can't XOpenDisplay");
@@ -44,9 +45,14 @@ main(int argc, char *argv[])
 		if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "-v") == 0)
 			usage(argv);
 		errno = 0;
-		win = (Window)strtol(argv[1], NULL, 0);
-		if (errno)
-			usage(argv);
+		win = (Window)strtol(argv[1], &ep, 0);
+		if (errno || argv[1] == ep || *ep != '\0') {
+			fprintf(stderr, "strtol: invalid number: \"%s\"%s%s\n",
+				argv[1],
+			        errno ? ": " : "",
+			        errno ? strerror(errno) : "");
+			exit(1);
+		}
 	} else {
 		win = RootWindow(dpy, 0);
 	}