Re: [PATCH (optional)] t0021: use arithmetic expansion to trim whitespace from wc -c output

[Johannes Sixt <j6t@kdbg.org>]

Am 06.11.2016 um 16:45 schrieb Lars Schneider:
> 
>> On 03 Nov 2016, at 21:22, Johannes Sixt <j6t@kdbg.org> wrote:
>> This is a pure optimization that reduces the number of forks, which
>> helps a bit on Windows.
>>
>> There would be a solution with perl that does not require trimming
>> of whitespace, but perl startup times are unbearable on Windows.
>> wc -c is better.

I was wrong here. I had looked at the perl invocations due to
git-sendemail, and they are awfully slow. A do-almost-nothing perl
invocation is in the same ballpark as wc. Therefore I changed my mind
and suggest the patch below instead.

> Since the file size function became very simple with your patch,
> shouldn't we get rid of it? If you agree, then we could squash the 
> patch below into your patch.

In the new patch, the function is not that trivial (it uses perl), and
the call sites can remain as they are (simple shell variables and
substitutions).

---- 8< ----
[PATCH] t0021: compute file size with a single process instead of a pipeline

Avoid unwanted coding patterns (prodigal use of pipelines), and in
particular a useless use of cat.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
---
 t/t0021-conversion.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index db71acacb3..cb72fa49de 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -22,7 +22,7 @@ generate_random_characters () {
 }
 
 file_size () {
-	cat "$1" | wc -c | sed "s/^[ ]*//"
+	perl -e 'print -s $ARGV[0]' "$1"
 }
 
 filter_git () {
-- 
2.11.0.rc0.55.gd967357