gawk

commit 8e595a498d1835ac8515200142477251c2dd4e89
parent f93bc3de44e7de77994865b862783316b4736f75
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Sat, 19 Dec 2020 22:04:03 -0800

Add fully functional gopher-text format piping

Diffstat:
M
main.c
 | 
50
++++++++++++++++++++++++++++++++++++++++++++++++--

1 file changed, 48 insertions(+), 2 deletions(-)
diff --git a/main.c b/main.c
@@ -25,6 +25,7 @@
 #include <limits.h>
 #include <netdb.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -35,6 +36,8 @@
 #define ARGV_MAX	16
 #define ARG_SEP		":\t "
 
+static char *gphfmt[] = { "gophmt", NULL };
+
 int	gawk(int depth, const char *tmpdir, const char *host, const char *path, const char *port);
 
 int
@@ -230,7 +233,9 @@ putfile(const char *path)
 		return 1;
 
 	while ((bytes = fread(buf, 1, sizeof(buf), in)) > 0) {
-		if (fwrite(buf, 1, bytes, stdout) != bytes) {
+                /* NOTE: using fwrite and `stdout` causes piping
+                 * to not work. */
+		if (write(STDOUT_FILENO, buf, bytes) != bytes) {
 			fclose(in);
 			warn("unable to write buffer");
 			return 1;
@@ -274,8 +279,49 @@ gphcache(const char *cache, const char *host, const char *path, const char *port
 int
 gawkat(const char *path)
 {
-	if (putfile(path) != 0)
+	int fds[2];
+	int i;
+
+	if (pipe(fds) == -1) {
+		warn("unable to setup pipe");
+		return 1;
+	}
+
+	switch (fork()) {
+	case -1:
+		warn("unable to fork");
 		return 1;
+	case 0:
+		if (dup2(fds[0], STDIN_FILENO) == -1 || close(fds[0]) || close(fds[1])) {
+			warn("unable to setup child pipe");
+			_exit(EXIT_FAILURE);
+		}
+		execvp(*gphfmt, gphfmt);
+		warn("execvp '%s'", *gphfmt);
+		_exit(EXIT_FAILURE);
+	}
+
+	switch (fork()) {
+	case -1:
+		warn("unable to fork");
+		return 1;
+	case 0:
+		if (dup2(fds[1], STDOUT_FILENO) == -1 || close(fds[0]) || close(fds[1])) {
+			warn("unable to setup parent pipe");
+			_exit(1);
+		}
+		if (putfile(path) != 0)
+			_exit(1);
+		_exit(0);
+	}
+
+	for (i = 0; i < 2; ++i)
+		close(fds[i]);
+	for (i = 0; i < 2; ++i) {
+		if (wait(0) == -1)
+			warn("unable to wait");
+	}
+
 	return 0;
 }