qna/subproc.c: channel IO in nonblocking mode

1 files changed, 25 insertions, 1 deletions

diff --git a/qna/subproc.c b/qna/subproc.c
index c040810..91f2616 100644
--- a/qna/subproc.c
+++ b/qna/subproc.c
@@ -7,6 +7,7 @@
 #include <signal.h>
 
 #include <unistd.h>
+#include <fcntl.h>
 #include <wait.h>
 #include <poll.h>
 
@@ -29,6 +30,24 @@ struct pbuf {
 	int fd;
 };
 
+static bool setnonblock (const int fd, const bool set) {
+	int fr;
+
+	fr = fcntl(fd, F_GETFL, 0);
+	if (fr < 0) {
+		return false;
+	}
+
+	if (set) {
+		fr |= O_NONBLOCK;
+	}
+	else {
+		fr &= ~O_NONBLOCK;
+	}
+
+	return fcntl(fd, F_SETFL, fr) >= 0;
+}
+
 static size_t do_output (const int fd, char *buf, size_t len) {
 	char *end;
 	size_t outlen;
@@ -87,12 +106,17 @@ int main (const int argc, const char **argv) {
 			close(p.in[0]);
 			close(p.out[1]);
 			close(p.err[1]);
+
 			sp->std.in = p.in[1];
 			pfds[j].fd = sp->std.out = p.out[0];
 			pfds[j + 1].fd = sp->std.err = p.err[0];
 			pfds[j].events = pfds[j + 1].events = POLLIN;
 			pbufs[j].fd = STDOUT_FILENO;
 			pbufs[j + 1].fd = STDERR_FILENO;
+
+			setnonblock(sp->std.in, true);
+			setnonblock(sp->std.out, true);
+			setnonblock(sp->std.err, true);
 		}
 		else if (sp->pid == 0) {
 			const char *new_argv[] = { "find", path, NULL };
@@ -180,7 +204,7 @@ int main (const int argc, const char **argv) {
 	}
 
 	while (wait(&s) >= 0) {
-		if (WIFEXITED(s) && WEXITSTATUS(s) != 0) {
+		if (WIFSIGNALED(s) || WEXITSTATUS(s) != 0) {
 			ec = 1;
 		}
 	}