From: Jeff King <peff@peff.net>
Date: Tue, 22 Jul 2008 07:12:46 +0000 (-0400)
Subject: run-command: add pre-exec callback
X-Git-Tag: v1.6.1-rc1~343^2~1
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=ccf08bc3d06050fbe9b76846f6e2ab6d1cd6bd09;p=git.git

run-command: add pre-exec callback

This is a function provided by the caller which is called
_after_ the process is forked, but before the spawned
program is executed. On platforms (like mingw) where
subprocesses are forked and executed in a single call, the
preexec callback is simply ignored.

This will be used in the following patch to do some setup
for 'less' that must happen in the forked child.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/run-command.c b/run-command.c
index 6e29fdf9e..73d0c3127 100644
--- a/run-command.c
+++ b/run-command.c
@@ -110,6 +110,8 @@ int start_command(struct child_process *cmd)
 					unsetenv(*cmd->env);
 			}
 		}
+		if (cmd->preexec_cb)
+			cmd->preexec_cb();
 		if (cmd->git_cmd) {
 			execv_git_cmd(cmd->argv);
 		} else {
diff --git a/run-command.h b/run-command.h
index 5203a9ebb..4f2b7d7d4 100644
--- a/run-command.h
+++ b/run-command.h
@@ -42,6 +42,7 @@ struct child_process {
 	unsigned no_stderr:1;
 	unsigned git_cmd:1; /* if this is to be git sub-command */
 	unsigned stdout_to_stderr:1;
+	void (*preexec_cb)(void);
 };
 
 int start_command(struct child_process *);