Add timeout to reading block output

1 files changed, 36 insertions, 10 deletions

diff --git a/wmsl.c b/wmsl.c
index 7a3f051..631044c 100644
--- a/wmsl.c
+++ b/wmsl.c
@@ -1,13 +1,14 @@
-#include <stdlib.h>
-#include <stdio.h>
+#include <X11/Xlib.h>
+
+#include <unistd.h>
+#include <signal.h>
+#include <time.h>
 #include <math.h>
 #include <string.h>
-#include <time.h>
-#include <unistd.h>
 #include <stdarg.h>
-#include <signal.h>
-
-#include <X11/Xlib.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
 
 #define ARRSIZE(x) (sizeof(x)/sizeof(x[0]))
 #define OUTPUTMAX  256
@@ -91,6 +92,33 @@ concat_status(const char *text, size_t len)
 	status_text[status_len] = '\0';
 }
 
+bool
+read_statusline(int fd, char *buf, size_t size)
+{
+	struct timeval timeout;
+	fd_set fdset;
+	int ret, nread;
+	char *tok;
+
+	FD_ZERO(&fdset);
+	FD_SET(fd, &fdset);
+
+	timeout.tv_sec = 1;
+	timeout.tv_usec = 0;
+
+	ret = select(fd + 1, &fdset, NULL, NULL, &timeout);
+	if (ret <= 0) return false;
+
+	nread = read(fd, buf, size);
+	if (!nread) return false;
+
+	if (!(tok = strchr(buf, '\n')))
+		return false;
+	*tok = '\0';
+
+	return true;
+}
+
 void
 update_blocks(void)
 {
@@ -114,12 +142,10 @@ update_blocks(void)
 			cmd = popen(blocks[i].command, "r");
 			if (!cmd) continue;
 
-			if (!fgets(tmp_output, OUTPUTMAX, cmd)) {
+			if (!read_statusline(fileno(cmd), tmp_output, OUTPUTMAX)) {
 				output_len = 0;
 			} else {
 				output_len = strlen(tmp_output);
-				if (tmp_output[output_len - 1] == '\n')
-					output_len -= 1;
 			}
 
 			pclose(cmd);