Re: [PATCH] pre-commit.sample: don't use [...] around a tr range

[Jim Meyering <jim@meyering.net>]

Jeff King wrote:

> On Mon, Sep 21, 2009 at 01:00:34PM +0200, Jim Meyering wrote:
>
>> > We have (had?) people trying to support Git on HP-UX and SunOS.
>> > Do these count?
>>
>> I had my doubts, but have just confirmed that Solaris 10's
>> /usr/bin/tr is still doing it the SYSV way:
>>
>>     $ echo foo | LC_ALL=C /usr/bin/tr a-z A-Z
>>     foo
>>
>> There, you have to use /usr/xpg4/bin/tr to get the expected behavior:
>>
>>     $ echo foo | LC_ALL=C /usr/xpg4/bin/tr a-z A-Z
>>     FOO
>>
>> So you're right.  Thanks!
>
> See:
>
>   http://article.gmane.org/gmane.comp.version-control.git/76991
>
>> +	# Note that the use of brackets around a tr range is ok here, (it's
>> +	# even required, for portability to Solaris 10's /usr/bin/tr), since
>> +	# the square bracket bytes happen to fall in the designated range.
>>  	test "$(git diff --cached --name-only --diff-filter=A -z |
>>  	  LC_ALL=C tr -d '[ -~]\0')"
>
> Does this work on non-bracket systems?

Yes, since [] happen to fall in the range.

> I would think that enumerating
> the sequence would be the most portable thing.

Enumerating is more portable, at the expense of
readability and maintainability.
In case you want to go that route, here's one more:

(note that this, like the original range, treats TAB as nonportable)

>From 40a368a7bcf0ac6524bbe36ba3bfdaa0711897b8 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@redhat.com>
Date: Mon, 21 Sep 2009 10:58:02 +0200
Subject: [PATCH] pre-commit.sample: use tr more portability; fix grammar

Avoid tr's M-N range notation altogether.
Instead, enumerate ascii bytes 32..126.
Correct spelling and grammar.

Signed-off-by: Jim Meyering <meyering@redhat.com>
---
 templates/hooks--pre-commit.sample |   19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/templates/hooks--pre-commit.sample b/templates/hooks--pre-commit.sample
index b11ad6a..896eb9e 100755
--- a/templates/hooks--pre-commit.sample
+++ b/templates/hooks--pre-commit.sample
@@ -10,19 +10,26 @@
 # If you want to allow non-ascii filenames set this variable to true.
 allownonascii=$(git config hooks.allownonascii)

+printables=' !"#$%&'\''()*+,-./0123456789:;<=>?@'
+printables="$printables"'ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`'
+printables="$printables"'abcdefghijklmnopqrstuvwxyz{|}~'
+
 # Cross platform projects tend to avoid non-ascii filenames; prevent
 # them from being added to the repository. We exploit the fact that the
 # printable range starts at the space character and ends with tilde.
 if [ "$allownonascii" != "true" ] &&
-	test "$(git diff --cached --name-only --diff-filter=A -z |
-	  LC_ALL=C tr -d '[ -~]\0')"
+	# Filter out printable ascii bytes, and NUL.
+	# If anything remains, you lose.
+        rem=$(git diff --cached --name-only --diff-filter=A -z |
+	      LC_ALL=C tr -d "$printables"'\0')
+	test -n "$rem"
 then
-	echo "Error: Attempt to add a non-ascii filename."
+	echo "Error: Attempt to add a non-ascii file name."
 	echo
-	echo "This can cause problems if you want to work together"
-	echo "with people on other platforms than you."
+	echo "This can cause problems if you want to work"
+	echo "with people on other platforms."
 	echo
-	echo "To be portable it is adviseable to rename the file ..."
+	echo "To be portable it is advisable to rename the file ..."
 	echo
 	echo "If you know what you are doing you can disable this"
 	echo "check using:"
--
1.6.5.rc1.214.g13c5a