Re: Weird behavior of shell variables in git aliases
- From
Jeff King <peff@peff.net>
- Date
- Mar 22, 2011, 13:28 UTC
- Message-ID
- <20110322132820.GA14559@sigill.intra.peff.net>
- In-Reply-To
- <20110322111844.GA32446@sigill.intra.peff.net>
On Tue, Mar 22, 2011 at 07:18:44AM -0400, Jeff King wrote:
Show 25 quoted lines
> Doesn't it also break a lot of other more garden-variety aliases that > rely on the automagic "$@", like: > > $ git config alias.log-nopager > !git --no-pager log > [...] > $ GIT_TRACE=1 git.master log-nopager --oneline > trace: exec: 'git-log-nopager' '--oneline' > trace: run_command: 'git-log-nopager' '--oneline' > trace: run_command: 'git --no-pager log' '--oneline' > trace: exec: 'sh' '-c' 'git --no-pager log "$@"' 'git --no-pager log' '--oneline' > trace: built-in: git 'log' '--oneline' > 93c7d44 foo > > $ GIT_TRACE=1 git.jch.shell-alias log-nopager --oneline > trace: exec: 'git-log-nopager' '--oneline' > trace: run_command: 'git-log-nopager' '--oneline' > trace: run_command: 'sh' '-c' 'git --no-pager log' '-' '--oneline' > trace: exec: 'sh' '-c' 'git --no-pager log' '-' '--oneline' > trace: built-in: git 'log' > commit 93c7d44635e8bb56a4fd864d024ce75a2ad4ffcf > Author: Jeff King <peff@peff.net> > Date: Tue Mar 22 06:57:02 2011 -0400 > > foo
One other solution would be to make the "$@" more magic by detecting when the alias uses positional parameters and omitting it in that case. Something like (on top of your patch):
diff --git a/git.c b/git.c index 8d54466..1daf89c 100644 --- a/git.c +++ b/git.c @@ -161,6 +161,27 @@ static int handle_options(const char ***argv, int *argc, int *envchanged) return handled; } +static int alias_uses_positional_parameters(const char *s) +{ + while ((s = strchr(s, '$'))) + if (s[1] == '@' || s[1] == '#' || + (s[1] >= '1' && s[1] <= '9')) + return 1; + return 0; +} + +static char *alias_to_shell(const char *in) +{ + struct strbuf out = STRBUF_INIT; + + if (alias_uses_positional_parameters(in)) + return xstrdup(in); + + strbuf_addstr(&out, in); + strbuf_addstr(&out, " \"$@\""); + return strbuf_detach(&out, NULL); +} + static int handle_alias(int *argcp, const char ***argv) { int envchanged = 0, ret = 0, saved_errno = errno; @@ -186,7 +207,7 @@ static int handle_alias(int *argcp, const char ***argv) alias_argv = xmalloc(sizeof(*alias_argv) * (argc + 4)); alias_argv[0] = "sh"; alias_argv[1] = "-c"; - alias_argv[2] = alias_string + 1; + alias_argv[2] = alias_to_shell(alias_string + 1); alias_argv[3] = "-"; for (i = 1; i < argc; ++i) alias_argv[i + 3] = (*argv)[i]; But I think that is a little too magic for my taste. Although the false positives ("!echo 'literal $#'") and false negatives (you want "!foo" to _ignore_ its parameters) are pretty obscure, I would prefer to keep things simple. -Peff