threads / patch / 2868

patchgit-grep: convert from bash to sh

Subject: [PATCH] git-grep: convert from bash to sh

## tl;dr

5 messages between Dec 18, 2005 and Dec 18, 2005. Diffs are folded; open one to read it.

replies: 4people: 4as markdown or json

Timo Hirvonen· Dec 18, 2005, 13:26 UTC · lore
sh does not support arrays so we have to use eval instead.
Signed-off-by: Timo Hirvonen <tihirvon@gmail.com>
---
 git-grep.sh |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)
11c29a066288c5f05a67ff0d46e9ce17cd7a37da
Show changes to git-grep.sh +7 −7
diff --git a/git-grep.sh b/git-grep.sh
index 2ed8e95..2f0a297 100755
--- a/git-grep.sh
+++ b/git-grep.sh
@@ -8,21 +8,21 @@ SUBDIRECTORY_OK='Yes'
 . git-sh-setup
 
 pattern=
-flags=()
-git_flags=()
+flags=
+git_flags=
 while : ; do
 	case "$1" in
 	--cached|--deleted|--others|--killed|\
 	--ignored|--exclude=*|\
 	--exclude-from=*|\--exclude-per-directory=*)
-		git_flags=("${git_flags[@]}" "$1")
+		git_flags="$git_flags '$1'"
 		;;
 	-e)
 		pattern="$2"
 		shift
 		;;
 	-A|-B|-C|-D|-d|-f|-m)
-		flags=("${flags[@]}" "$1" "$2")
+		flags="$flags '$1' '$2'"
 		shift
 		;;
 	--)
@@ -31,7 +31,7 @@ while : ; do
 		break
 		;;
 	-*)
-		flags=("${flags[@]}" "$1")
+		flags="$flags '$1'"
 		;;
 	*)
 		if [ -z "$pattern" ]; then
@@ -46,5 +46,5 @@ done
 [ "$pattern" ] || {
 	usage
 }
-git-ls-files -z "${git_flags[@]}" "$@" |
-	xargs -0 grep "${flags[@]}" -e "$pattern"
+eval git-ls-files -z "$git_flags" '"$@"' |
+	eval xargs -0 grep "$flags" -e '"$pattern"'
-- 
0.99.9.GIT
Petr Baudis· Dec 18, 2005, 14:56 UTC · re: Timo Hirvonen · lore

Re: [PATCH] git-grep: convert from bash to sh

Dear diary, on Sun, Dec 18, 2005 at 02:26:39PM CET, I got a letter where Timo Hirvonen <tihirvon@gmail.com> said that...

> sh does not support arrays so we have to use eval instead.
> 
> Signed-off-by: Timo Hirvonen <tihirvon@gmail.com>

This version also makes it work properly with patterns containing quotes and backslashes (not so unusual when you grep for C strings).

Signed-off-by: Petr Baudis <pasky@suse.cz>
---

I'm kind of sensitive to this stuff. I still passionately hate scp making me to double-quote remote filenames. It's just evil.

Show changes to git-grep.sh +8 −7
diff --git a/git-grep.sh b/git-grep.sh
index 2ed8e95..7e9e5bf 100755
--- a/git-grep.sh
+++ b/git-grep.sh
@@ -8,21 +8,21 @@ SUBDIRECTORY_OK='Yes'
 . git-sh-setup
 
 pattern=
-flags=()
-git_flags=()
+flags=
+git_flags=
 while : ; do
 	case "$1" in
 	--cached|--deleted|--others|--killed|\
 	--ignored|--exclude=*|\
 	--exclude-from=*|\--exclude-per-directory=*)
-		git_flags=("${git_flags[@]}" "$1")
+		git_flags="$git_flags '$1'"
 		;;
 	-e)
 		pattern="$2"
 		shift
 		;;
 	-A|-B|-C|-D|-d|-f|-m)
-		flags=("${flags[@]}" "$1" "$2")
+		flags="$flags '$1' '$2'"
 		shift
 		;;
 	--)
@@ -31,7 +31,7 @@ while : ; do
 		break
 		;;
 	-*)
-		flags=("${flags[@]}" "$1")
+		flags="$flags '$1'"
 		;;
 	*)
 		if [ -z "$pattern" ]; then
@@ -46,5 +46,6 @@ done
 [ "$pattern" ] || {
 	usage
 }
-git-ls-files -z "${git_flags[@]}" "$@" |
-	xargs -0 grep "${flags[@]}" -e "$pattern"
+pattern="$(echo "$pattern" | sed 's/[\\"]/\\&/g')"
+eval git-ls-files -z "$git_flags" '"$@"' |
+	eval xargs -0 grep "$flags" -e '"$pattern"'
-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
VI has two modes: the one in which it beeps and the one in which
it doesn't.
Junio C Hamano· Dec 18, 2005, 19:37 UTC · re: Petr Baudis · lore

Re: [PATCH] git-grep: convert from bash to sh

Petr Baudis <pasky@suse.cz> writes:
> I'm kind of sensitive to this stuff. I still passionately hate scp
> making me to double-quote remote filenames. It's just evil.
OK.
>  	--ignored|--exclude=*|\
>  	--exclude-from=*|\--exclude-per-directory=*)
> -		git_flags=("${git_flags[@]}" "$1")
> +		git_flags="$git_flags '$1'"
SQs in --exclude= or --exclude-from= parameter?  E.g.
	git grep --exclude-from="/cygdrive/c/pasky's patterns/cvsignore" \
		-e foobar
>  	-A|-B|-C|-D|-d|-f|-m)
> -		flags=("${flags[@]}" "$1" "$2")
> +		flags="$flags '$1' '$2'"
>  		shift

SQs in $2 for -f. About other flags, -[ABCm] take only numbers and -[Dd] take read/skip/recurse, so as long as your user does not screw up you are OK. And malicious users are shooting themselves in the foot here so we might not care too much being loose.

Show 9 quoted lines
> @@ -46,5 +46,6 @@ done
>  [ "$pattern" ] || {
>  	usage
>  }
> -git-ls-files -z "${git_flags[@]}" "$@" |
> -	xargs -0 grep "${flags[@]}" -e "$pattern"
> +pattern="$(echo "$pattern" | sed 's/[\\"]/\\&/g')"
> +eval git-ls-files -z "$git_flags" '"$@"' |
> +	eval xargs -0 grep "$flags" -e '"$pattern"'

You are not expanding $pattern in the outer shell that builds eval arguments (letting the inner shell expand "$pattern" and use it), so I do not think you need that sed script to muck with it there. The eval'ed string is literally "$pattern" including double quotes because you have sq around the last parameter to "eval" command, and eval would do the right thing, no?

Actually the use of sed script there is actively wrong. When a file contains these lines:

        printf("%s is not there\n");
        printf("\"%s\" is not there\n");
the command to pick up the second line should be:
	$ git-grep -e '\\"%s\\"'

but I think your version passes \\\\\"%s\\\\\ to underlying grep. Removing that single line would make it do the right thing, I think.

Enough nitpicking. If you want to stay in shell and want to avoid shell array, you would either need to be a bit more careful if you are going to use eval, or do something like what I originally did, which made Linus' brain shut down and had him gouge his eyes with a spoon. It is the one that this one is a response to:

	http://marc.theaimsgroup.com/?l=git&m=112656882627760

Not that I am suggesting the latter is better than a bit more careful 'eval' construction ;-).

I am not happy with that [@] thing either. I have the attached laying around in my working tree --- I do not remember if I finished it or not; it's a WIP when I thought about this issue last time and wondered if we might be better off rewriting the whole thing.

-- >8 -- #!/usr/bin/perl # # Copyright (c) 2005 Junio C Hamano #

use strict; my (@git_flag, @grep_flag, $pattern); my $nargs = 100;

my (%git_ls_files_flag) =
    map { '--' . $_ => 1 }
    qw{cached deleted others kiled ignored
       exclude= exclude-from= exclude-per-directory=};
sub is_git_flag {
    my ($arg) = @_;
    $arg =~ s/^([^=]*)=/$1/;
    return (exists $git_ls_files_flag{$arg});
}
while (@ARGV) {
    my ($arg) = shift @ARGV;
    if (is_git_flag($arg)) {
	push @git_flag, $arg;
    }
    elsif ($arg eq '-e') {
	$pattern = shift @ARGV;
    }
    elsif ($arg =~ /^-[ABCDdfm]$/) {
	push @grep_flag, $arg, (shift @ARGV);
    }
    elsif ($arg =~ /^--$/) {
	shift @ARGV;
	last;
    }
    elsif ($arg =~ /^-/) {
	push @grep_flag, $arg;
    }
    elsif (! defined $pattern) {
	$pattern = $arg;
	last;
    }
    else {
	last;
    }
}
my $ih;
open $ih, '-|', qw(git-ls-files -z), @git_flag, @ARGV;
$/ = "\0";
my @args = ();
while (<$ih>) {
    chomp;
    push @args, $_;
    if ($nargs <= @args) {
	system 'grep', @grep_flag, '-e', $pattern, @args;
	@args = ();
    }
}
close $ih;
if (@args) {
    system 'grep', @grep_flag, '-e', $pattern, @args;
}
Linus Torvalds· Dec 18, 2005, 19:57 UTC · re: Timo Hirvonen · lore

Re: [PATCH] git-grep: convert from bash to sh

On Sun, 18 Dec 2005, Timo Hirvonen wrote:
> 
> sh does not support arrays so we have to use eval instead.
This seems horribly broken.
If I'm not mistaken, this breaks
	git grep "it's a happy coincidence"
badly. I didn't test, just looking at the patch.
Dammit, I'd rather depend on "bash"/"ksh" than have a broken "git grep".
Tell people to get a real shell.
		Linus
Timo Hirvonen· Dec 18, 2005, 20:18 UTC · re: Linus Torvalds · lore

Re: [PATCH] git-grep: convert from bash to sh

On Sun, 18 Dec 2005 11:57:26 -0800 (PST) Linus Torvalds <torvalds@osdl.org> wrote:

Show 11 quoted lines
> On Sun, 18 Dec 2005, Timo Hirvonen wrote:
> > 
> > sh does not support arrays so we have to use eval instead.
> 
> This seems horribly broken.
> 
> If I'm not mistaken, this breaks
> 
> 	git grep "it's a happy coincidence"
> 
> badly. I didn't test, just looking at the patch.
Actually it works:

/usr/src/linux-2.6: git grep "it's a" Documentation/Changes:debugfs. Obviously, it's a good idea to upgrade. Documentation/CodingStyle:and NOT read it. Burn them, it's a great symbolic gesture.

but it doesn't work with backslashes.  Need to use \\

/usr/src/linux-2.6: git grep 'e.\\n"' Documentation/DMA-mapping.txt: "mydev: No suitable DMA available.\n"); Documentation/DMA-mapping.txt: "mydev: No suitable DMA available.\n");

-- 
http://onion.dynserv.net/~timo/

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