threads / patch / 34810

patchTeach git to change to a given directory using -C option

Subject: [PATCH] Teach git to change to a given directory using -C option

## tl;dr

2 messages between Aug 30, 2013 and Sep 1, 2013. Diffs are folded; open one to read it.

replies: 1people: 2as markdown or json

Nazri Ramliy· Aug 30, 2013, 13:35 UTC · lore

This is similar in spirit to to "make -C dir ..." and "tar -C dir ...".

Currently it takes more effort (keypresses) to invoke git command in a different directory than the current one without leaving the current directory:

    1. (cd ~/foo && git status)
       git --git-dir=~/foo/.git --work-dir=~/foo status
       GIT_DIR=~/foo/.git GIT_WORK_TREE=~/foo git status
    2. (cd ../..; git grep foo)
    3. for d in d1 d2 d3; do (cd $d && git svn rebase); done

While doable the methods shown above are arguably more suitable for scripting than quick command line invocations.

With this new option, the above can be done with less keystrokes:

    1. git -C ~/foo status
    2. git -C ../.. grep foo
    3. for d in d1 d2 d3; do git -C $d svn rebase; done

A new test script is added to verify the behavior of this option with other path-related options like --git-dir and --work-tree.

Signed-off-by: Nazri Ramliy <ayiehere@gmail.com>
---
This is a reroll of [1]. The only difference is the rewording of the
commit message.  I'm resending this as I've found it to be useful in my
daily git usage in that it helps me stay focused on what I'm doing in
the current directory while needing to run git on another directory.

nazri.

[1] http://permalink.gmane.org/gmane.comp.version-control.git/221954

 Documentation/git.txt | 13 +++++++++
 git.c                 | 15 ++++++++--
 t/t0056-git-C.sh      | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 102 insertions(+), 2 deletions(-)
 create mode 100755 t/t0056-git-C.sh

Show changes to 3 files +102 −2

Documentation/git.txt, git.c, t/t0056-git-C.sh

diff --git a/Documentation/git.txt b/Documentation/git.txt
index dca11cc..0d44fa2 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -395,6 +395,19 @@ displayed. See linkgit:git-help[1] for more information,
 because `git --help ...` is converted internally into `git
 help ...`.
 
+-C <directory>::
+	Run as if git were started in <directory> instead of the current
+	working directory. If multiple -C options are given, subsequent
+	directory arguments are interpreted relative to the previous one: -C
+	/usr -C src is equivalent to -C /usr/src. This option affects options
+	that expect path name like --git-dir and --work-tree in that their
+	interpretations of the path names would be made relative to the
+	effective working directory caused by the -C option. For example the
+	following invocations are equivalent:
+
+	    git --git-dir=a.git --work-tree=b -C c status
+	    git --git-dir=c/a.git --work-tree=c/b status
+
 -c <name>=<value>::
 	Pass a configuration parameter to the command. The value
 	given will override values from configuration files.
diff --git a/git.c b/git.c
index 2025f77..2207ee5 100644
--- a/git.c
+++ b/git.c
@@ -7,7 +7,7 @@
 #include "commit.h"
 
 const char git_usage_string[] =
-	"git [--version] [--help] [-c name=value]\n"
+	"git [--version] [--help] [-C directory] [-c name=value]\n"
 	"           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
 	"           [-p|--paginate|--no-pager] [--no-replace-objects] [--bare]\n"
 	"           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
@@ -54,7 +54,18 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 		/*
 		 * Check remaining flags.
 		 */
-		if (!prefixcmp(cmd, "--exec-path")) {
+		if (!strcmp(cmd, "-C")) {
+			if (*argc < 2) {
+				fprintf(stderr, "No directory given for -C.\n" );
+				usage(git_usage_string);
+			}
+			if (chdir((*argv)[1]))
+				die_errno("Cannot change to '%s'", (*argv)[1]);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
+		} else if (!prefixcmp(cmd, "--exec-path")) {
 			cmd += 11;
 			if (*cmd == '=')
 				git_set_argv_exec_path(cmd + 1);
diff --git a/t/t0056-git-C.sh b/t/t0056-git-C.sh
new file mode 100755
index 0000000..370eae6
--- /dev/null
+++ b/t/t0056-git-C.sh
@@ -0,0 +1,76 @@
+#!/bin/sh
+
+test_description='"-C <directory>" option and it effects on other path-related options'
+
+. ./test-lib.sh
+
+test_expect_success '"git -C <dir>" runs git from the directory <dir>' '
+	test_create_repo dir1 &&
+	echo 1 >dir1/a.txt &&
+	(cd dir1 && git add a.txt && git commit -m "initial in dir1") &&
+	expected="initial in dir1" &&
+	actual=$(git -C dir1 log --format=%s) &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Multiple -C options: "-C dir1 -C dir2" is equivalent to "-C dir1/dir2"' '
+	test_create_repo dir1/dir2 &&
+	echo 1 >dir1/dir2/a.txt &&
+	git -C dir1/dir2 add a.txt &&
+	expected="initial in dir1/dir2" &&
+	git -C dir1/dir2 commit -m "$expected" &&
+	actual=$(git -C dir1 -C dir2 log --format=%s) &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Effect on --git-dir option: "-C c --git-dir=a.git" is equivalent to "--git-dir c/a.git"' '
+	mkdir c &&
+	mkdir c/a &&
+	mkdir c/a.git &&
+	(cd c/a.git && git init --bare) &&
+	echo 1 >c/a/a.txt &&
+	git --git-dir c/a.git --work-tree=c/a add a.txt &&
+	git --git-dir c/a.git --work-tree=c/a commit -m "initial" &&
+	expected="$(git --git-dir=c/a.git log -1 --format=%s)" &&
+	actual=$(git -C c --git-dir=a.git log -1 --format=%s) &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Order should not matter: "--git-dir=a.git -C c" is equivalent to "-C c --git-dir=a.git"' '
+	expected="$(git -C c --git-dir=a.git log -1 --format=%s)" &&
+	actual=$(git --git-dir=a.git -C c log -1 --format=%s) &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Effect on --work-tree option: "-C c/a.git --work-tree=../a"  is equivalent to "--work-tree=c/a --git-dir=c/a.git"' '
+	rm c/a/a.txt &&
+	expected="$(git --git-dir=c/a.git --work-tree=c/a status)" &&
+	actual="$(git -C c/a.git --work-tree=../a status)" &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Order should not matter: "--work-tree=../a -C c/a.git" is equivalent to "-C c/a.git --work-tree=../a"' '
+	expected="$(git -C c/a.git --work-tree=../a status)" &&
+	actual="$(git --work-tree=../a -C c/a.git status)" &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Effect on --git-dir and --work-tree options - "-C c --git-dir=a.git --work-tree=a" is equivalent to "--git-dir=c/a.git --work-tree=c/a"' '
+	expected="$(git --git-dir=c/a.git --work-tree=c/a status)" &&
+	actual="$(git -C c --git-dir=a.git --work-tree=a status)" &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Order should not matter: "-C c --git-dir=a.git --work-tree=a" is equivalent to "--git-dir=a.git -C c --work-tree=a"' '
+	expected="$(git -C c --git-dir=a.git --work-tree=a status)" &&
+	actual="$(git --git-dir=a.git -C c --work-tree=a status)" &&
+	test "$expected" = "$actual"
+'
+
+test_expect_success 'Order should not matter: "-C c --git-dir=a.git --work-tree=a" is equivalent to "--git-dir=a.git --work-tree=a -C c"' '
+	expected="$(git -C c --git-dir=a.git --work-tree=a status)" &&
+	actual="$(git --git-dir=a.git --work-tree=a -C c status)" &&
+	test "$expected" = "$actual"
+'
+
+test_done

-- 
1.8.4.1.g098df5a

Eric Sunshine· Sep 1, 2013, 04:48 UTC · re: Nazri Ramliy · lore

Re: [PATCH] Teach git to change to a given directory using -C option

On Fri, Aug 30, 2013 at 9:35 AM, Nazri Ramliy <ayiehere@gmail.com> wrote:

Show 16 quoted lines

> This is similar in spirit to to "make -C dir ..." and "tar -C dir ...".
>
> Currently it takes more effort (keypresses) to invoke git command in a
> different directory than the current one without leaving the current
> directory:
>
>     1. (cd ~/foo && git status)
>        git --git-dir=~/foo/.git --work-dir=~/foo status
>        GIT_DIR=~/foo/.git GIT_WORK_TREE=~/foo git status
>     2. (cd ../..; git grep foo)
>     3. for d in d1 d2 d3; do (cd $d && git svn rebase); done
>
> While doable the methods shown above are arguably more suitable for
> scripting than quick command line invocations.
>
> With this new option, the above can be done with less keystrokes:

Grammar: s/less/fewer/

More below...

Show 33 quoted lines

>     1. git -C ~/foo status
>     2. git -C ../.. grep foo
>     3. for d in d1 d2 d3; do git -C $d svn rebase; done
>
> A new test script is added to verify the behavior of this option with
> other path-related options like --git-dir and --work-tree.
>
> Signed-off-by: Nazri Ramliy <ayiehere@gmail.com>
> ---
> This is a reroll of [1]. The only difference is the rewording of the
> commit message.  I'm resending this as I've found it to be useful in my
> daily git usage in that it helps me stay focused on what I'm doing in
> the current directory while needing to run git on another directory.
>
> nazri.
>
> [1] http://permalink.gmane.org/gmane.comp.version-control.git/221954
>
>  Documentation/git.txt | 13 +++++++++
>  git.c                 | 15 ++++++++--
>  t/t0056-git-C.sh      | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 102 insertions(+), 2 deletions(-)
>  create mode 100755 t/t0056-git-C.sh
>
> diff --git a/Documentation/git.txt b/Documentation/git.txt
> index dca11cc..0d44fa2 100644
> --- a/Documentation/git.txt
> +++ b/Documentation/git.txt
> @@ -395,6 +395,19 @@ displayed. See linkgit:git-help[1] for more information,
>  because `git --help ...` is converted internally into `git
>  help ...`.
>
> +-C <directory>::

The synopsis at the top of git.txt mentions --git-dir and --work-tree. For consistency, -C probably ought to be mentioned there, as well.

Other options which accept a directory, such as --git-dir and --work-tree, are documented as accepting <path>, but -C is inconsistently documented as accepting <directory>.

> +       Run as if git were started in <directory> instead of the current
> +       working directory. If multiple -C options are given, subsequent
> +       directory arguments are interpreted relative to the previous one: -C
> +       /usr -C src is equivalent to -C /usr/src. This option affects options

The fragment "interpreted relative" seems ambiguous when absolute paths are involved. For instance, what happens when the user specifies "-C /foo/ -C /bar/". From the implementation I can see that the working directory becomes /bar, but without checking the implementation, it's not clear what the result would be. For instance, if the implementation merely did string concatenation of the -C arguments, then input "-C /foo/ -C /bar/" might try to set the working directory to "/foo//bar/" which would be interpreted as "/foo/bar/" on Unix, but would probably fail on Windows. Perhaps rewriting might remove the ambiguity?

    [...] When multiple -C options are given, each subsequent non-absolute
    -C <path> is interpreted relative to the preceding -C <path>. [...]

Show 24 quoted lines

> +       that expect path name like --git-dir and --work-tree in that their
> +       interpretations of the path names would be made relative to the
> +       effective working directory caused by the -C option. For example the
> +       following invocations are equivalent:
> +
> +           git --git-dir=a.git --work-tree=b -C c status
> +           git --git-dir=c/a.git --work-tree=c/b status
> +
>  -c <name>=<value>::
>         Pass a configuration parameter to the command. The value
>         given will override values from configuration files.
> diff --git a/git.c b/git.c
> index 2025f77..2207ee5 100644
> --- a/git.c
> +++ b/git.c
> @@ -7,7 +7,7 @@
>  #include "commit.h"
>
>  const char git_usage_string[] =
> -       "git [--version] [--help] [-c name=value]\n"
> +       "git [--version] [--help] [-C directory] [-c name=value]\n"
>         "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
>         "           [-p|--paginate|--no-pager] [--no-replace-objects] [--bare]\n"
>         "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"

For existing options accepting an argument, the argument is formatted as <argument>. The -C option does not follow suit.

As mentioned above, all other options accepting a directory are documented as taking <path>, but -C is inconsistent and is documented as taking 'directory' instead.

Show 29 quoted lines

> @@ -54,7 +54,18 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
>                 /*
>                  * Check remaining flags.
>                  */
> -               if (!prefixcmp(cmd, "--exec-path")) {
> +               if (!strcmp(cmd, "-C")) {
> +                       if (*argc < 2) {
> +                               fprintf(stderr, "No directory given for -C.\n" );
> +                               usage(git_usage_string);
> +                       }
> +                       if (chdir((*argv)[1]))
> +                               die_errno("Cannot change to '%s'", (*argv)[1]);
> +                       if (envchanged)
> +                               *envchanged = 1;
> +                       (*argv)++;
> +                       (*argc)--;
> +               } else if (!prefixcmp(cmd, "--exec-path")) {
>                         cmd += 11;
>                         if (*cmd == '=')
>                                 git_set_argv_exec_path(cmd + 1);
> diff --git a/t/t0056-git-C.sh b/t/t0056-git-C.sh
> new file mode 100755
> index 0000000..370eae6
> --- /dev/null
> +++ b/t/t0056-git-C.sh
> @@ -0,0 +1,76 @@
> +#!/bin/sh
> +
> +test_description='"-C <directory>" option and it effects on other path-related options'

s/it/its/ s/<directory>/<path>/

> +
> +. ./test-lib.sh
> +
> +test_expect_success '"git -C <dir>" runs git from the directory <dir>' '

s/<dir>/<path>/g

Show 7 quoted lines

> +       test_create_repo dir1 &&
> +       echo 1 >dir1/a.txt &&
> +       (cd dir1 && git add a.txt && git commit -m "initial in dir1") &&
> +       expected="initial in dir1" &&
> +       actual=$(git -C dir1 log --format=%s) &&
> +       test "$expected" = "$actual"
> +'

Modern git tests tend to place the expected and actual outputs in files and then use test_cmp to verify that they are identical. For instance:

    echo "initial in dir1" >expected &&
    git -C dir1 log --format="%s" >actual &&
    test_cmp expected actual

The benefit of doing so is that test_cmp will print the difference between the expected and actual values when they differ, which facilitates debugging a failed test.

Show 9 quoted lines

> +test_expect_success 'Multiple -C options: "-C dir1 -C dir2" is equivalent to "-C dir1/dir2"' '
> +       test_create_repo dir1/dir2 &&
> +       echo 1 >dir1/dir2/a.txt &&
> +       git -C dir1/dir2 add a.txt &&
> +       expected="initial in dir1/dir2" &&
> +       git -C dir1/dir2 commit -m "$expected" &&
> +       actual=$(git -C dir1 -C dir2 log --format=%s) &&
> +       test "$expected" = "$actual"
> +'

It would make sense also to test multiple -C options with combinations of absolute and and relative paths.

Show 53 quoted lines

> +test_expect_success 'Effect on --git-dir option: "-C c --git-dir=a.git" is equivalent to "--git-dir c/a.git"' '
> +       mkdir c &&
> +       mkdir c/a &&
> +       mkdir c/a.git &&
> +       (cd c/a.git && git init --bare) &&
> +       echo 1 >c/a/a.txt &&
> +       git --git-dir c/a.git --work-tree=c/a add a.txt &&
> +       git --git-dir c/a.git --work-tree=c/a commit -m "initial" &&
> +       expected="$(git --git-dir=c/a.git log -1 --format=%s)" &&
> +       actual=$(git -C c --git-dir=a.git log -1 --format=%s) &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_expect_success 'Order should not matter: "--git-dir=a.git -C c" is equivalent to "-C c --git-dir=a.git"' '
> +       expected="$(git -C c --git-dir=a.git log -1 --format=%s)" &&
> +       actual=$(git --git-dir=a.git -C c log -1 --format=%s) &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_expect_success 'Effect on --work-tree option: "-C c/a.git --work-tree=../a"  is equivalent to "--work-tree=c/a --git-dir=c/a.git"' '
> +       rm c/a/a.txt &&
> +       expected="$(git --git-dir=c/a.git --work-tree=c/a status)" &&
> +       actual="$(git -C c/a.git --work-tree=../a status)" &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_expect_success 'Order should not matter: "--work-tree=../a -C c/a.git" is equivalent to "-C c/a.git --work-tree=../a"' '
> +       expected="$(git -C c/a.git --work-tree=../a status)" &&
> +       actual="$(git --work-tree=../a -C c/a.git status)" &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_expect_success 'Effect on --git-dir and --work-tree options - "-C c --git-dir=a.git --work-tree=a" is equivalent to "--git-dir=c/a.git --work-tree=c/a"' '
> +       expected="$(git --git-dir=c/a.git --work-tree=c/a status)" &&
> +       actual="$(git -C c --git-dir=a.git --work-tree=a status)" &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_expect_success 'Order should not matter: "-C c --git-dir=a.git --work-tree=a" is equivalent to "--git-dir=a.git -C c --work-tree=a"' '
> +       expected="$(git -C c --git-dir=a.git --work-tree=a status)" &&
> +       actual="$(git --git-dir=a.git -C c --work-tree=a status)" &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_expect_success 'Order should not matter: "-C c --git-dir=a.git --work-tree=a" is equivalent to "--git-dir=a.git --work-tree=a -C c"' '
> +       expected="$(git -C c --git-dir=a.git --work-tree=a status)" &&
> +       actual="$(git --git-dir=a.git --work-tree=a -C c status)" &&
> +       test "$expected" = "$actual"
> +'
> +
> +test_done
> --
> 1.8.4.1.g098df5a