Start of "git-send-pack", the local part of sending off a pack

Like git-receive-pack, this is only partway done.

Makefile

@@ -37,7 +37,7 @@ PROG=   git-update-cache git-diff-files git-init-db git-write-tree \
 	git-get-tar-commit-id git-apply git-stripspace \
 	git-cvs2git git-diff-stages git-rev-parse git-patch-id \
 	git-pack-objects git-unpack-objects git-verify-pack \
-	git-receive-pack
+	git-receive-pack git-send-pack
 
 all: $(PROG)
 
@@ -127,6 +127,7 @@ git-pack-objects: pack-objects.c
 git-unpack-objects: unpack-objects.c
 git-verify-pack: verify-pack.c
 git-receive-pack: receive-pack.c
+git-send-pack: send-pack.c
 
 git-http-pull: LIBS += -lcurl
 git-rev-list: LIBS += -lssl

send-pack.c

+#include "cache.h"
+
+static const char send_pack_usage[] = "git-send-pack [--exec=other] destination [heads]*";
+
+static const char *exec = "git-receive-pack";
+
+static int send_pack(int in, int out)
+{
+	for (;;) {
+		static char buffer[1000];
+		int ret = read(in, buffer, sizeof(buffer));
+		if (ret > 0) {
+			write(1, buffer, ret);
+			continue;
+		}
+		break;
+	}
+	close(out);
+	return 0;
+}
+
+/*
+ * First, make it shell-safe.  We do this by just disallowing any
+ * special characters. Somebody who cares can do escaping and let
+ * through the rest. But since we're doing to feed this to ssh as
+ * a command line, we're going to be pretty damn anal for now.
+ */
+static char *shell_safe(char *url)
+{
+	char *n = url;
+	unsigned char c;
+	static const char flags[256] = {
+		['0'...'9'] = 1,
+		['a'...'z'] = 1,
+		['A'...'Z'] = 1,
+		['.'] = 1, ['/'] = 1,
+		['-'] = 1, ['+'] = 1,
+		[':'] = 1
+	};
+
+	while ((c = *n++) != 0) {
+		if (flags[c] != 1)
+			die("I don't like '%c'. Sue me.", c);
+	}
+	return url;
+}
+
+/*
+ * Yeah, yeah, fixme. Need to pass in the heads etc.
+ */
+static int setup_connection(int fd[2], char *url, char **heads)
+{
+	char command[1024];
+	const char *host, *path;
+	char *colon;
+	int pipefd[2][2];
+
+	url = shell_safe(url);
+	host = NULL;
+	path = url;
+	colon = strchr(url, ':');
+	if (colon) {
+		*colon = 0;
+		host = url;
+		path = colon+1;
+	}
+	snprintf(command, sizeof(command), "%s %s", exec, path);
+	if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
+		die("unable to create pipe pair for communication");
+	if (!fork()) {
+		dup2(pipefd[1][0], 0);
+		dup2(pipefd[0][1], 1);
+		close(pipefd[0][0]);
+		close(pipefd[0][1]);
+		close(pipefd[1][0]);
+		close(pipefd[1][1]);
+		if (host)
+			execlp("ssh", "ssh", host, command, NULL);
+		else
+			execlp(host, command, NULL);
+		die("exec failed");
+	}		
+	fd[0] = pipefd[0][0];
+	fd[1] = pipefd[1][1];
+	close(pipefd[0][1]);
+	close(pipefd[1][0]);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int i, nr_heads = 0;
+	char *dest = NULL;
+	char **heads = NULL;
+	int fd[2];
+
+	argv++;
+	for (i = 1; i < argc; i++) {
+		char *arg = *argv++;
+
+		if (*arg == '-') {
+			if (!strncmp(arg, "--exec=", 7)) {
+				exec = arg + 7;
+				continue;
+			}
+			usage(send_pack_usage);
+		}
+		dest = arg;
+		heads = argv;
+		nr_heads = argc - i -1;
+		break;
+	}
+	if (!dest)
+		usage(send_pack_usage);
+	if (setup_connection(fd, dest, heads))
+		return 1;
+	return send_pack(fd[0], fd[1]);
+}