[PATCH v2 1/6] run-command: Allow stderr to be a caller supplied pipe

From

Shawn O. Pearce <spearce@spearce.org>

Date

Feb 5, 2010, 20:57 UTC

Message-ID

<1265403462-20572-2-git-send-email-spearce@spearce.org>

In-Reply-To

<1265403462-20572-1-git-send-email-spearce@spearce.org>

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 Documentation/technical/api-run-command.txt |    2 +-
 run-command.c                               |    8 ++++++++
 run-command.h                               |    2 +-
 3 files changed, 10 insertions(+), 2 deletions(-)

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 @@ stderr as follows:
 
 	.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 @@ fail_pipe:
 		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 @@ fail_pipe:
 	} 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 @@ fail_pipe:
 
 	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 @@ struct child_process {
 	 * - 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!
 	 */

-- 
1.7.0.rc1.199.g9253ab