Extract process-management functionality into a new lib/process

Note that procmon does *not* go here, since procmon needs to
integrate with the event loop.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/lib/process/pidfile.c b/src/lib/process/pidfile.c
new file mode 100644
index 0000000000..f016f21697
--- /dev/null
+++ b/src/lib/process/pidfile.c
@@ -0,0 +1,47 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#include "orconfig.h"
+#include "lib/process/pidfile.h"
+
+#include "lib/log/torlog.h"
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+/** Write the current process ID, followed by NL, into <b>filename</b>.
+ * Return 0 on success, -1 on failure.
+ */
+int
+write_pidfile(const char *filename)
+{
+  FILE *pidfile;
+
+  if ((pidfile = fopen(filename, "w")) == NULL) {
+    log_warn(LD_FS, "Unable to open \"%s\" for writing: %s", filename,
+             strerror(errno));
+    return -1;
+  } else {
+#ifdef _WIN32
+    int pid = (int)_getpid();
+#else
+    int pid = (int)getpid();
+#endif
+    int rv = 0;
+    if (fprintf(pidfile, "%d\n", pid) < 0)
+      rv = -1;
+    if (fclose(pidfile) < 0)
+      rv = -1;
+    return rv;
+  }
+}