[PATCH 4/4] [MAIN] Optimize dash -c "command" to avoid a fork

[Jonathan Nieder <jrnieder@xxxxxxxxx>]

From: Jilles Tjoelker <jilles@xxxxxxxx>
Date: Sat, 13 Jun 2009 16:17:45 -0500

This change only affects strings passed to -c, when the -s option is
not used.

Use the EV_EXIT flag to inform the eval machinery that the string
being passed is the entirety of input.  This way, a fork may be
omitted in many special cases.

If there are empty lines after the last command, the evalcmd will not
see the end early enough and forks will not be omitted. The same thing
seems to happen in bash.

Example:
  sh -c 'ps lT'
No longer shows a shell process waiting for ps to finish.

[jn: ported from FreeBSD SVN r194128.  Bugs are mine.]

Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
---
 src/main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/main.c b/src/main.c
index b38dc27..af987c6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -171,7 +171,7 @@ state2:
 state3:
 	state = 4;
 	if (minusc)
-		evalstring(minusc, 0);
+		evalstring(minusc, sflag ? 0 : EV_EXIT);
 
 	if (sflag || minusc == NULL) {
 state4:	/* XXX ??? - why isn't this before the "if" statement */
-- 
1.7.5.rc0

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