1 file changed, 82 insertions, 0 deletions
diff --git a/filter.c b/filter.c
new file mode 100644
index 0000000..f4ee9ac
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,82 @@
+/* filter.c: filter framework functions
+ *
+ * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
+#include "cgit.h"
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+
+int cgit_open_filter(struct cgit_filter *filter)
+{
+	filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
+		"Unable to duplicate STDOUT");
+	chk_zero(pipe(filter->pipe_fh), "Unable to create pipe to subprocess");
+	filter->pid = chk_non_negative(fork(), "Unable to create subprocess");
+	if (filter->pid == 0) {
+		close(filter->pipe_fh[1]);
+		chk_non_negative(dup2(filter->pipe_fh[0], STDIN_FILENO),
+			"Unable to use pipe as STDIN");
+		execvp(filter->cmd, filter->argv);
+		die_errno("Unable to exec subprocess %s", filter->cmd);
+	}
+	close(filter->pipe_fh[0]);
+	chk_non_negative(dup2(filter->pipe_fh[1], STDOUT_FILENO),
+		"Unable to use pipe as STDOUT");
+	close(filter->pipe_fh[1]);
+	return 0;
+}
+
+
+int cgit_close_filter(struct cgit_filter *filter)
+{
+	int exit_status;
+
+	chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
+		"Unable to restore STDOUT");
+	close(filter->old_stdout);
+	if (filter->pid < 0)
+		return 0;
+	waitpid(filter->pid, &exit_status, 0);
+	if (WIFEXITED(exit_status) && !WEXITSTATUS(exit_status))
+		return 0;
+	die("Subprocess %s exited abnormally", filter->cmd);
+}
+
+struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
+{
+	struct cgit_filter *f;
+	int args_size = 0;
+	int extra_args;
+
+	if (!cmd || !cmd[0])
+		return NULL;
+
+	switch (filtertype) {
+		case SOURCE:
+		case ABOUT:
+			extra_args = 1;
+			break;
+
+		case COMMIT:
+		default:
+			extra_args = 0;
+			break;
+	}
+	
+	f = xmalloc(sizeof(struct cgit_filter));
+	memset(f, 0, sizeof(struct cgit_filter));
+
+	f->cmd = xstrdup(cmd);
+	args_size = (2 + extra_args) * sizeof(char *);
+	f->argv = xmalloc(args_size);
+	memset(f->argv, 0, args_size);
+	f->argv[0] = f->cmd;
+	return f;
+}