[PATCH 3/6] run-command: optimize out useless shell calls
- From
Jeff King <peff@peff.net>
- Date
- Dec 30, 2009, 10:55 UTC
- Message-ID
- <20091230105536.GC22959@coredump.intra.peff.net>
- In-Reply-To
- <20091230095634.GA16349@coredump.intra.peff.net>
If there are no metacharacters in the program to be run, we can just skip running the shell entirely and directly exec the program.
The metacharacter test is pulled verbatim from launch_editor, which already implements this optimization.
Signed-off-by: Jeff King <peff@peff.net> --- Something inside me feels wrong with a catch-known-metacharacter test instead of an allow-known-good check. But this is the same test we have been using with launch_editor for some time, so I decided not to mess with it.
run-command.c | 18 ++++++++++-------- 1 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/run-command.c b/run-command.c index dc65903..22e2777 100644 --- a/run-command.c +++ b/run-command.c @@ -28,15 +28,17 @@ static const char **prepare_shell_cmd(const char **argv) if (argc < 1) die("BUG: shell command is empty"); - nargv[nargc++] = "sh"; - nargv[nargc++] = "-c"; - - if (argc < 2) - nargv[nargc++] = argv[0]; - else { - struct strbuf arg0 = STRBUF_INIT; - strbuf_addf(&arg0, "%s \"$@\"", argv[0]); - nargv[nargc++] = strbuf_detach(&arg0, NULL); + if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) { + nargv[nargc++] = "sh"; + nargv[nargc++] = "-c"; + + if (argc < 2) + nargv[nargc++] = argv[0]; + else { + struct strbuf arg0 = STRBUF_INIT; + strbuf_addf(&arg0, "%s \"$@\"", argv[0]); + nargv[nargc++] = strbuf_detach(&arg0, NULL); + } } for (argc = 0; argv[argc]; argc++)
-- 1.6.6.65.g050d2.dirty