# [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation

5 messages from 2009-08-20 to 2009-08-20. Participants: Brandon Casey, Johan Herland, Junio C Hamano.
Thread: https://gitlist.dev/t/20669

## Brandon Casey, 2009-08-20 01:24

Subject: [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation
Message-ID: <QHfHFS_5JGiL-O8GMDfdfscFUdxV1xVObzr6e5LPleagDRd7bCg8I9YUwL9xkbgM64vyf_EVLLg@cipher.nrlssc.navy.mil>
URL: https://gitlist.dev/e/QHfHFS_5JGiL-O8GMDfdfscFUdxV1xVObzr6e5LPleagDRd7bCg8I9YUwL9xkbgM64vyf_EVLLg%40cipher.nrlssc.navy.mil

```
From: Brandon Casey <drafnel@gmail.com>

The substring expansion notation is a bashism that we have not so far
adopted.  There is precedence for using the 'cut' utility for extracting
a substring.  So do so here.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
---
 t/t7407-submodule-foreach.sh |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index de1730d..44ea8ac 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -207,8 +207,8 @@ cat > expect <<EOF
  $nested2sha1 nested1/nested2 (heads/master)
  $nested3sha1 nested1/nested2/nested3 (heads/master)
  $submodulesha1 nested1/nested2/nested3/submodule (heads/master)
- $sub1sha1 sub1 (${sub1sha1:0:7})
- $sub2sha1 sub2 (${sub1sha1:0:7})
+ $sub1sha1 sub1 ($(echo $sub1sha1 | cut -c 1-7))
+ $sub2sha1 sub2 ($(echo $sub1sha1 | cut -c 1-7))
  $sub3sha1 sub3 (heads/master)
 EOF
 
-- 
1.6.4

```

## Johan Herland, 2009-08-20 06:56

Subject: Re: [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation
Message-ID: <200908200856.30359.johan@herland.net>
URL: https://gitlist.dev/e/200908200856.30359.johan%40herland.net
In-Reply-To: <QHfHFS_5JGiL-O8GMDfdfscFUdxV1xVObzr6e5LPleagDRd7bCg8I9YUwL9xkbgM64vyf_EVLLg@cipher.nrlssc.navy.mil>

```
On Thursday 20 August 2009, Brandon Casey wrote:
> From: Brandon Casey <drafnel@gmail.com>
>
> The substring expansion notation is a bashism that we have not so far
> adopted.  There is precedence for using the 'cut' utility for extracting
> a substring.  So do so here.
>
> Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
> ---
>  t/t7407-submodule-foreach.sh |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
> index de1730d..44ea8ac 100755
> --- a/t/t7407-submodule-foreach.sh
> +++ b/t/t7407-submodule-foreach.sh
> @@ -207,8 +207,8 @@ cat > expect <<EOF
>   $nested2sha1 nested1/nested2 (heads/master)
>   $nested3sha1 nested1/nested2/nested3 (heads/master)
>   $submodulesha1 nested1/nested2/nested3/submodule (heads/master)
> - $sub1sha1 sub1 (${sub1sha1:0:7})
> - $sub2sha1 sub2 (${sub1sha1:0:7})
> + $sub1sha1 sub1 ($(echo $sub1sha1 | cut -c 1-7))
> + $sub2sha1 sub2 ($(echo $sub1sha1 | cut -c 1-7))

Typo (both in the original, and the patch), should be:
	$sub2sha1 sub2 ($(echo $sub2sha1 | cut -c 1-7))

>   $sub3sha1 sub3 (heads/master)
>  EOF

Otherwise:

Acked-by: Johan Herland <johan@herland.net>

Thanks,


...Johan

-- 
Johan Herland, <johan@herland.net>
www.herland.net

```

## Junio C Hamano, 2009-08-20 07:34

Subject: Re: [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation
Message-ID: <7vskfnq6q5.fsf@alter.siamese.dyndns.org>
URL: https://gitlist.dev/e/7vskfnq6q5.fsf%40alter.siamese.dyndns.org
In-Reply-To: <200908200856.30359.johan@herland.net>

```
Johan Herland <johan@herland.net> writes:

>> - $sub1sha1 sub1 (${sub1sha1:0:7})
>> - $sub2sha1 sub2 (${sub1sha1:0:7})
>> + $sub1sha1 sub1 ($(echo $sub1sha1 | cut -c 1-7))
>> + $sub2sha1 sub2 ($(echo $sub1sha1 | cut -c 1-7))
>
> Typo (both in the original, and the patch), should be:
> 	$sub2sha1 sub2 ($(echo $sub2sha1 | cut -c 1-7))
>
>>   $sub3sha1 sub3 (heads/master)
>>  EOF
>
> Otherwise:
>
> Acked-by: Johan Herland <johan@herland.net>

Hmm, what does the command use to shorten these object names?  It may be
safer and more correct to use "rev-parse --short" in case these object
names were ambigous in their first 7 hexdigits.

```

## Johan Herland, 2009-08-20 09:24

Subject: Re: [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation
Message-ID: <200908201124.54193.johan@herland.net>
URL: https://gitlist.dev/e/200908201124.54193.johan%40herland.net
In-Reply-To: <7vskfnq6q5.fsf@alter.siamese.dyndns.org>

```
On Thursday 20 August 2009, Junio C Hamano wrote:
> Johan Herland <johan@herland.net> writes:
> >> - $sub1sha1 sub1 (${sub1sha1:0:7})
> >> - $sub2sha1 sub2 (${sub1sha1:0:7})
> >> + $sub1sha1 sub1 ($(echo $sub1sha1 | cut -c 1-7))
> >> + $sub2sha1 sub2 ($(echo $sub1sha1 | cut -c 1-7))
> >
> > Typo (both in the original, and the patch), should be:
> > 	$sub2sha1 sub2 ($(echo $sub2sha1 | cut -c 1-7))
> >
> >>   $sub3sha1 sub3 (heads/master)
> >>  EOF
> >
> > Otherwise:
> >
> > Acked-by: Johan Herland <johan@herland.net>
>
> Hmm, what does the command use to shorten these object names?  It may be
> safer and more correct to use "rev-parse --short" in case these object
> names were ambigous in their first 7 hexdigits.

git submodule status (which is what we're testing here) uses
'git describe' to generate the short object name (see
set_name_rev in git-submodule.sh). In this case, it falls back
to 'git describe --all --always', which calls find_unique_abbrev()
on the SHA1. 'git rev-parse --short' ends up calling the same
find_unique_abbrev(), so I guess it is better to use it here.

Try this instead:

From: Johan Herland <johan@herland.net>

Subject: [PATCH] t7407: Use 'rev-parse --short' rather than bash's substring expansion notation

The substring expansion notation is a bashism that we have not so far
adopted.  Use 'git rev-parse --short' instead, as this also handles
the case where the unique abbreviation is longer than 7 characters.

Suggested-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Johan Herland <johan@herland.net>
---
 t/t7407-submodule-foreach.sh |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 25ec281..2a52775 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -201,14 +201,16 @@ submodulesha1=$(cd clone3/nested1/nested2/nested3/submodule && git rev-parse HEA
 sub1sha1=$(cd clone3/sub1 && git rev-parse HEAD)
 sub2sha1=$(cd clone3/sub2 && git rev-parse HEAD)
 sub3sha1=$(cd clone3/sub3 && git rev-parse HEAD)
+sub1sha1_short=$(cd clone3/sub1 && git rev-parse --short HEAD)
+sub2sha1_short=$(cd clone3/sub2 && git rev-parse --short HEAD)
 
 cat > expect <<EOF
  $nested1sha1 nested1 (heads/master)
  $nested2sha1 nested1/nested2 (heads/master)
  $nested3sha1 nested1/nested2/nested3 (heads/master)
  $submodulesha1 nested1/nested2/nested3/submodule (heads/master)
- $sub1sha1 sub1 (${sub1sha1:0:7})
- $sub2sha1 sub2 (${sub1sha1:0:7})
+ $sub1sha1 sub1 ($sub1sha1_short)
+ $sub2sha1 sub2 ($sub2sha1_short)
  $sub3sha1 sub3 (heads/master)
 EOF
 
-- 
1.6.4.304.g1365c.dirty

-- 
Johan Herland, <johan@herland.net>
www.herland.net

```

## Brandon Casey, 2009-08-20 16:59

Subject: Re: [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation
Message-ID: <5cqGRKnaah8NEt1Sx1jHwTRuuDfhT5e-wsLOzZOw4Hf1ady-n-TFfg@cipher.nrlssc.navy.mil>
URL: https://gitlist.dev/e/5cqGRKnaah8NEt1Sx1jHwTRuuDfhT5e-wsLOzZOw4Hf1ady-n-TFfg%40cipher.nrlssc.navy.mil
In-Reply-To: <200908201124.54193.johan@herland.net>

```
Johan Herland wrote:
> On Thursday 20 August 2009, Junio C Hamano wrote:
>> Johan Herland <johan@herland.net> writes:
>>>> - $sub1sha1 sub1 (${sub1sha1:0:7})
>>>> - $sub2sha1 sub2 (${sub1sha1:0:7})
>>>> + $sub1sha1 sub1 ($(echo $sub1sha1 | cut -c 1-7))
>>>> + $sub2sha1 sub2 ($(echo $sub1sha1 | cut -c 1-7))
>>> Typo (both in the original, and the patch), should be:
>>> 	$sub2sha1 sub2 ($(echo $sub2sha1 | cut -c 1-7))
>>>
>>>>   $sub3sha1 sub3 (heads/master)
>>>>  EOF
>>> Otherwise:
>>>
>>> Acked-by: Johan Herland <johan@herland.net>
>> Hmm, what does the command use to shorten these object names?  It may be
>> safer and more correct to use "rev-parse --short" in case these object
>> names were ambigous in their first 7 hexdigits.
> 
> git submodule status (which is what we're testing here) uses
> 'git describe' to generate the short object name (see
> set_name_rev in git-submodule.sh). In this case, it falls back
> to 'git describe --all --always', which calls find_unique_abbrev()
> on the SHA1. 'git rev-parse --short' ends up calling the same
> find_unique_abbrev(), so I guess it is better to use it here.
> 
> Try this instead:
> 
> From: Johan Herland <johan@herland.net>
> 
> Subject: [PATCH] t7407: Use 'rev-parse --short' rather than bash's substring expansion notation
> 
> The substring expansion notation is a bashism that we have not so far
> adopted.  Use 'git rev-parse --short' instead, as this also handles
> the case where the unique abbreviation is longer than 7 characters.

Works for me.

Maybe it should be mentioned that a typo was fixed too.

-brandon

```