threads / patch / 19035

patch, 3 partsrev-parse: add --sq-quote to shell quote arguments

Subject: [PATCH 1/3] rev-parse: add --sq-quote to shell quote arguments

## tl;dr

5 messages between Apr 24, 2009 and Apr 25, 2009. Diffs are folded; open one to read it.

replies: 4people: 3as markdown or json

Christian Couder· Apr 24, 2009, 06:28 UTC · lore

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 Documentation/git-rev-parse.txt |   18 ++++++++++++++++++
 builtin-rev-parse.c             |   15 +++++++++++++++
 2 files changed, 33 insertions(+), 0 deletions(-)

Show changes to 2 files +33 −0

Documentation/git-rev-parse.txt, builtin-rev-parse.c

diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index fba30b1..239704c 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -30,6 +30,9 @@ OPTIONS
 	Only meaningful in `--parseopt` mode. Tells the option parser to echo
 	out the first `--` met instead of skipping it.
 
+--sq-quote::
+	Use 'git-rev-parse' in shell quoting mode (see SQ-QUOTE section below).
+
 --revs-only::
 	Do not output flags and parameters not meant for
 	'git-rev-list' command.
@@ -406,6 +409,21 @@ C?        option C with an optional argument"
 eval `echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?`
 ------------
 
+SQ-QUOTE
+--------
+
+In `--sq-quote` mode, 'git-rev-parse' echoes on the standard output a
+single line suitable for `sh(1)` `eval`. This line is made by
+normalizing the arguments following `--sq-quote`.
+
+Example
+~~~~~~~
+
+------------
+$ git rev-parse --sq-quote "'''" '"""' "arg with space"
+ ''\'''\'''\''' '"""' 'arg with space'
+------------
+
 EXAMPLES
 --------
 
diff --git a/builtin-rev-parse.c b/builtin-rev-parse.c
index 22c6d6a..c5b3d6e 100644
--- a/builtin-rev-parse.c
+++ b/builtin-rev-parse.c
@@ -402,6 +402,18 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+static int cmd_sq_quote(int argc, const char **argv)
+{
+	struct strbuf buf = STRBUF_INIT;
+
+	if (argc)
+		sq_quote_argv(&buf, argv, 0);
+	printf("%s\n", buf.buf);
+	strbuf_release(&buf);
+
+	return 0;
+}
+
 static void die_no_single_rev(int quiet)
 {
 	if (quiet)
@@ -419,6 +431,9 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 	if (argc > 1 && !strcmp("--parseopt", argv[1]))
 		return cmd_parseopt(argc - 1, argv + 1, prefix);
 
+	if (argc > 1 && !strcmp("--sq-quote", argv[1]))
+		return cmd_sq_quote(argc - 2, argv + 2);
+
 	prefix = setup_git_directory();
 	git_config(git_default_config, NULL);
 	for (i = 1; i < argc; i++) {

-- 
1.6.3.rc1.112.g17e25

Junio C Hamano· Apr 24, 2009, 08:14 UTC · re: Christian Couder · lore

Re: [PATCH 1/3] rev-parse: add --sq-quote to shell quote arguments

Christian Couder <chriscool@tuxfamily.org> writes:

Show 7 quoted lines

> @@ -30,6 +30,9 @@ OPTIONS
>  	Only meaningful in `--parseopt` mode. Tells the option parser to echo
>  	out the first `--` met instead of skipping it.
>  
> +--sq-quote::
> +	Use 'git-rev-parse' in shell quoting mode (see SQ-QUOTE section below).
> +

Hmph, I wonder how this interacts with the existing --sq option to the same command in the mental model of end users.

Show 7 quoted lines

> +Example
> +~~~~~~~
> +
> +------------
> +$ git rev-parse --sq-quote "'''" '"""' "arg with space"
> + ''\'''\'''\''' '"""' 'arg with space'
> +------------

Yuck --- does asciidoc formats this correctly?

    ... goes and tries ...

Not very readable. A better example might be to demonstrate something like this:

	$ cat >your-git-script.sh <<\EOF
	#!/bin/sh
	# quote user-supplied arguments
	args=$(git rev-parse --sq-quote "$@")
        # and use it inside a handcrafted command line
        command="git frotz -n24 $args"
        eval "$command"
	EOF

	$ sh your-git-script.sh "a b'c"

i.e, put stress on how to use it, not on how it works internally.

Johannes Sixt· Apr 24, 2009, 08:33 UTC · re: Junio C Hamano · lore

Re: [PATCH 1/3] rev-parse: add --sq-quote to shell quote arguments

Junio C Hamano schrieb:

Show 15 quoted lines

> Not very readable.  A better example might be to demonstrate something
> like this:
> 
> 	$ cat >your-git-script.sh <<\EOF
> 	#!/bin/sh
> 	# quote user-supplied arguments
> 	args=$(git rev-parse --sq-quote "$@")
>         # and use it inside a handcrafted command line
>         command="git frotz -n24 $args"
>         eval "$command"
> 	EOF
> 
> 	$ sh your-git-script.sh "a b'c"
> 
> i.e, put stress on how to use it, not on how it works internally.

Hmm, that makes me wonder why we special-case shell-quoting and implement it in an executable. Why don't we have perl-quoting, C-quoting, PHP-quoting, $language-of-your-choice quoting, etc, too?

I think we should simply move sq() from git-am to git-sh-setup and use that in git-bisect.

-- Hannes

Christian Couder· Apr 25, 2009, 05:06 UTC · re: Johannes Sixt · lore

Re: [PATCH 1/3] rev-parse: add --sq-quote to shell quote arguments

Le vendredi 24 avril 2009, Johannes Sixt a écrit :

Show 20 quoted lines

> Junio C Hamano schrieb:
> > Not very readable.  A better example might be to demonstrate something
> > like this:
> >
> > 	$ cat >your-git-script.sh <<\EOF
> > 	#!/bin/sh
> > 	# quote user-supplied arguments
> > 	args=$(git rev-parse --sq-quote "$@")
> >         # and use it inside a handcrafted command line
> >         command="git frotz -n24 $args"
> >         eval "$command"
> > 	EOF
> >
> > 	$ sh your-git-script.sh "a b'c"
> >
> > i.e, put stress on how to use it, not on how it works internally.
>
> Hmm, that makes me wonder why we special-case shell-quoting and implement
> it in an executable. Why don't we have perl-quoting, C-quoting,
> PHP-quoting, $language-of-your-choice quoting, etc, too?

Because there are a lot of shell scripts in the Git source code and it's an important problem for shell scripts to properly handle arguments.

> I think we should simply move sq() from git-am to git-sh-setup and use
> that in git-bisect.

We already have an implementation of shell quoting in C, why not use it everywhere instead of having 2 implementations?

And what happens if someone want to port to C a shell script that uses sq()? The implementation used will have to be the one in C, so why not use it right now?

Regards, Christian.

Christian Couder· Apr 25, 2009, 04:57 UTC · re: Junio C Hamano · lore

Re: [PATCH 1/3] rev-parse: add --sq-quote to shell quote arguments

Le vendredi 24 avril 2009, Junio C Hamano a écrit :

Show 11 quoted lines

> Christian Couder <chriscool@tuxfamily.org> writes:
> > @@ -30,6 +30,9 @@ OPTIONS
> >  	Only meaningful in `--parseopt` mode. Tells the option parser to echo
> >  	out the first `--` met instead of skipping it.
> >
> > +--sq-quote::
> > +	Use 'git-rev-parse' in shell quoting mode (see SQ-QUOTE section
> > below). +
>
> Hmph, I wonder how this interacts with the existing --sq option to the
> same command in the mental model of end users.

I just sent a new version where difference between --sq and --sq-quote are discussed.

Show 27 quoted lines

> > +Example
> > +~~~~~~~
> > +
> > +------------
> > +$ git rev-parse --sq-quote "'''" '"""' "arg with space"
> > + ''\'''\'''\''' '"""' 'arg with space'
> > +------------
>
> Yuck --- does asciidoc formats this correctly?
>
>     ... goes and tries ...
>
> Not very readable.  A better example might be to demonstrate something
> like this:
>
> 	$ cat >your-git-script.sh <<\EOF
> 	#!/bin/sh
> 	# quote user-supplied arguments
> 	args=$(git rev-parse --sq-quote "$@")
>         # and use it inside a handcrafted command line
>         command="git frotz -n24 $args"
>         eval "$command"
> 	EOF
>
> 	$ sh your-git-script.sh "a b'c"
>
> i.e, put stress on how to use it, not on how it works internally.

I agree your example is better. I used it in the v2 I just sent.

Thanks, Christian.