[PATCH v2] alias: use run_command api to execute aliases

[PATCH v2] alias: use run_command api to execute aliases

[Erik Faye-Lund]

On Windows, system() executes with cmd.exe instead of /bin/sh. This
means that aliases currently has to be batch-scripts instead of
bourne-scripts. On top of that, cmd.exe does not handle single quotes,
which is what the code-path currently uses to handle arguments with
spaces.

To solve both problems in one go, use run_command_v_opt() to execute
the alias. It already does the right thing prepend "sh -c " to the
alias.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
---

Fixed the issues pointed out by Jonathan Nieder.

 git.c |   30 +++++++++++++++---------------
 1 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/git.c b/git.c
index 68334f6..f3666a8 100644
--- a/git.c
+++ b/git.c
@@ -177,22 +177,22 @@ static int handle_alias(int *argcp, const char ***argv)
 	alias_string = alias_lookup(alias_command);
 	if (alias_string) {
 		if (alias_string[0] == '!') {
+			const char **alias_argv;
+			int argc = *argcp, i;
+
 			commit_pager_choice();
-			if (*argcp > 1) {
-				struct strbuf buf;
-
-				strbuf_init(&buf, PATH_MAX);
-				strbuf_addstr(&buf, alias_string);
-				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
-				free(alias_string);
-				alias_string = buf.buf;
-			}
-			trace_printf("trace: alias to shell cmd: %s => %s\n",
-				     alias_command, alias_string + 1);
-			ret = system(alias_string + 1);
-			if (ret >= 0 && WIFEXITED(ret) &&
-			    WEXITSTATUS(ret) != 127)
-				exit(WEXITSTATUS(ret));
+
+			/* build alias_argv */
+			alias_argv = xmalloc(sizeof(char *) * argc + 1);
+			alias_argv[0] = alias_string + 1;
+			for (i = 1; i < argc; ++i)
+				alias_argv[i] = (*argv)[i];
+			alias_argv[argc] = NULL;
+
+			ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
+			if (ret >= 0)   /* normal exit */
+				exit(ret);
+
 			die("Failed to run '%s' when expanding alias '%s'",
 			    alias_string + 1, alias_command);
 		}
-- 
1.7.3.3.585.g74f6e

Re: [PATCH v2] alias: use run_command api to execute aliases

[Jonathan Nieder]

Erik Faye-Lund wrote:

> --- a/git.c
> +++ b/git.c
> @@ -177,22 +177,22 @@ static int handle_alias(int *argcp, const char ***argv)
[...]
> +			alias_argv = xmalloc(sizeof(char *) * argc + 1);

Missed a spot?  (missing parens)

Thanks for this.  It also should provide a minor speedup in the case
of commands with no shell metacharacters.

Re: [PATCH v2] alias: use run_command api to execute aliases

[Erik Faye-Lund]

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On Jan 6, 2011 9:05 PM, "Jonathan Nieder" <jrnieder@gmail.com> wrote:
>
> Erik Faye-Lund wrote:
>
> > --- a/git.c
> > +++ b/git.c
> > @@ -177,22 +177,22 @@ static int handle_alias(int *argcp, const char
***argv)
> [...]
> > +                     alias_argv = xmalloc(sizeof(char *) * argc + 1);
>
> Missed a spot?  (missing parens)
>

Blergh... I guess that teaches me a lesson about sending out patches in a
hurry. New version a bit later, then ;)

> Thanks for this.  It also should provide a minor speedup in the case
> of commands with no shell metacharacters.

Nice. Not intentional, but hey :)

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Re: [PATCH v2] alias: use run_command api to execute aliases

[Johannes Sixt]

On Donnerstag, 6. Januar 2011, Erik Faye-Lund wrote:
> @@ -177,22 +177,22 @@ static int handle_alias(int *argcp, const char
> ***argv) alias_string = alias_lookup(alias_command);
>  	if (alias_string) {
>  		if (alias_string[0] == '!') {
> +			const char **alias_argv;
> +			int argc = *argcp, i;
> +
>  			commit_pager_choice();
> -			if (*argcp > 1) {
> -				struct strbuf buf;
> -
> -				strbuf_init(&buf, PATH_MAX);
> -				strbuf_addstr(&buf, alias_string);
> -				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
> -				free(alias_string);
> -				alias_string = buf.buf;
> -			}
> -			trace_printf("trace: alias to shell cmd: %s => %s\n",
> -				     alias_command, alias_string + 1);
> -			ret = system(alias_string + 1);
> -			if (ret >= 0 && WIFEXITED(ret) &&
> -			    WEXITSTATUS(ret) != 127)
> -				exit(WEXITSTATUS(ret));
> +
> +			/* build alias_argv */
> +			alias_argv = xmalloc(sizeof(char *) * argc + 1);
> +			alias_argv[0] = alias_string + 1;
> +			for (i = 1; i < argc; ++i)
> +				alias_argv[i] = (*argv)[i];
> +			alias_argv[argc] = NULL;
> +
> +			ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
> +			if (ret >= 0)   /* normal exit */
> +				exit(ret);
> +
>  			die("Failed to run '%s' when expanding alias '%s'",
>  			    alias_string + 1, alias_command);

At this point, errno has a meaning. I'd perhaps change this to:

			die_errno("While expanding alias '%s': '%s'",
				alias_command, alias_string + 1);

-- Hannes