[tor-commits] [tor/master] Allow named pipes for our log files.

[nickm at torproject.org]

commit a32913d5aa816cdc41edbabf9b606b83aea6c835
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Aug 20 13:45:16 2014 -0400

    Allow named pipes for our log files.
    
    Closes ticket 12061. Based on a patch from "carlo von lynX" on tor-dev at
      https://lists.torproject.org/pipermail/tor-dev/2014-April/006705.html
---
 changes/bug12061    |    4 ++++
 src/common/compat.c |   13 +++++++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/changes/bug12061 b/changes/bug12061
new file mode 100644
index 0000000..308417c
--- /dev/null
+++ b/changes/bug12061
@@ -0,0 +1,4 @@
+  o Minor features:
+    - On unix, you can now use named pipes as the target of the Log
+      option, and other options that try to append to files. Closes
+      ticket 12061. Patch from "carlo von lynX".
diff --git a/src/common/compat.c b/src/common/compat.c
index c4f5987..eb9a70f 100644
--- a/src/common/compat.c
+++ b/src/common/compat.c
@@ -981,14 +981,23 @@ tor_fd_getpos(int fd)
 #endif
 }
 
-/** Move <b>fd</b> to the end of the file. Return -1 on error, 0 on success. */
+/** Move <b>fd</b> to the end of the file. Return -1 on error, 0 on success.
+ * If the file is a pipe, do nothing and succeed.
+ **/
 int
 tor_fd_seekend(int fd)
 {
 #ifdef _WIN32
   return _lseek(fd, 0, SEEK_END) < 0 ? -1 : 0;
 #else
-  return lseek(fd, 0, SEEK_END) < 0 ? -1 : 0;
+  int rc = lseek(fd, 0, SEEK_END) < 0 ? -1 : 0;
+#ifdef ESPIPE
+  /* If we get an error and ESPIPE, then it's a pipe or a socket of a fifo:
+   * no need to worry. */
+  if (rc < 0 && errno == ESPIPE)
+    rc = 0;
+#endif
+  return rc;
 #endif
 }