run-command: Allow stderr to be a caller supplied pipe
Like .out, .err may now be set to a file descriptor > 0, which
is a writable pipe/socket/file that the child's stderr will be
redirected into.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt
index b26c281..a1280dd 100644
--- a/Documentation/technical/api-run-command.txt
+++ b/Documentation/technical/api-run-command.txt
@@ -135,7 +135,7 @@
.in: The FD must be readable; it becomes child's stdin.
.out: The FD must be writable; it becomes child's stdout.
- .err > 0 is not supported.
+ .err: The FD must be writable; it becomes child's stderr.
The specified FD is closed by start_command(), even if it fails to
run the sub-process!
diff --git a/run-command.c b/run-command.c
index cf2d8f7..bfd2312 100644
--- a/run-command.c
+++ b/run-command.c
@@ -94,6 +94,9 @@
else if (need_err) {
dup2(fderr[1], 2);
close_pair(fderr);
+ } else if (cmd->err > 1) {
+ dup2(cmd->err, 2);
+ close(cmd->err);
}
if (cmd->no_stdout)
@@ -156,6 +159,9 @@
} else if (need_err) {
s2 = dup(2);
dup2(fderr[1], 2);
+ } else if (cmd->err > 2) {
+ s2 = dup(2);
+ dup2(cmd->err, 2);
}
if (cmd->no_stdout) {
@@ -228,6 +234,8 @@
if (need_err)
close(fderr[1]);
+ else if (cmd->err)
+ close(cmd->err);
return 0;
}
diff --git a/run-command.h b/run-command.h
index fb34209..a29171a 100644
--- a/run-command.h
+++ b/run-command.h
@@ -18,7 +18,7 @@
* - Specify > 0 to set a channel to a particular FD as follows:
* .in: a readable FD, becomes child's stdin
* .out: a writable FD, becomes child's stdout/stderr
- * .err > 0 not supported
+ * .err: a writable FD, becomes child's stderr
* The specified FD is closed by start_command(), even in case
* of errors!
*/
