[PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[Josh Triplett]

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Replace all uses of cat that do nothing other than read a single file.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
---
 git-commit.sh        |    2 +-
 git-filter-branch.sh |    4 ++--
 git-ls-remote.sh     |    2 +-
 git-quiltimport.sh   |    4 ++--
 git-verify-tag.sh    |    3 +--
 5 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/git-commit.sh b/git-commit.sh
index e8b60f7..06b6cd7 100755
--- a/git-commit.sh
+++ b/git-commit.sh
@@ -617,7 +617,7 @@ then
 		tree=$(GIT_INDEX_FILE="$TMP_INDEX" git-write-tree) &&
 		rm -f "$TMP_INDEX"
 	fi &&
-	commit=$(cat "$GIT_DIR"/COMMIT_MSG | git-commit-tree $tree $PARENTS) &&
+	commit=$(git-commit-tree $tree $PARENTS < "$GIT_DIR"/COMMIT_MSG) &&
 	rlogm=$(sed -e 1q "$GIT_DIR"/COMMIT_MSG) &&
 	git-update-ref -m "$GIT_REFLOG_ACTION: $rlogm" HEAD $commit "$current" &&
 	rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" &&
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 0c8a7df..bfac6f2 100644
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -333,7 +333,7 @@ for commit in $unchanged; do
 done
 
 git-rev-list --reverse --topo-order $srcbranch --not $unchanged >../revs
-commits=$(cat ../revs | wc -l | tr -d " ")
+commits=$(wc -l ../revs | tr -d " ")
 
 test $commits -eq 0 && die "Found nothing to rewrite"
 
@@ -386,7 +386,7 @@ while read commit; do
 done <../revs
 
 git-update-ref refs/heads/"$dstbranch" $(head -n 1 ../map/$(tail -n 1 ../revs))
-if [ "$(cat ../map/$(tail -n 1 ../revs) | wc -l)" -gt 1 ]; then
+if [ "$(wc -l ../map/$(tail -n 1 ../revs))" -gt 1 ]; then
 	echo "WARNING: Your commit filter caused the head commit to expand to several rewritten commits. Only the first such commit was recorded as the current $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
 	sed 's/^/	/' ../map/$(tail -n 1 ../revs) >&2
 	ret=1
diff --git a/git-ls-remote.sh b/git-ls-remote.sh
index a6ed99a..f5b2e77 100755
--- a/git-ls-remote.sh
+++ b/git-ls-remote.sh
@@ -82,7 +82,7 @@ rsync://* )
 	(cd $tmpdir && find refs -type f) |
 	while read path
 	do
-		cat "$tmpdir/$path" | tr -d '\012'
+		tr -d '\012' < "$tmpdir/$path"
 		echo "	$path"
 	done &&
 	rm -fr $tmpdir
diff --git a/git-quiltimport.sh b/git-quiltimport.sh
index a7a6757..bd540cd 100755
--- a/git-quiltimport.sh
+++ b/git-quiltimport.sh
@@ -70,9 +70,9 @@ tmp_info="$tmp_dir/info"
 commit=$(git-rev-parse HEAD)
 
 mkdir $tmp_dir || exit 2
-for patch_name in $(cat "$QUILT_PATCHES/series" | grep -v '^#'); do
+for patch_name in $(grep -v '^#' "$QUILT_PATCHES/series"); do
 	echo $patch_name
-	(cat $QUILT_PATCHES/$patch_name | git-mailinfo "$tmp_msg" "$tmp_patch" > "$tmp_info") || exit 3
+	git-mailinfo "$tmp_msg" "$tmp_patch" < "$QUILT_PATCHES/$patch_name" > "$tmp_info" || exit 3
 	test -s .dotest/patch || {
 		echo "Patch is empty.  Was it split wrong?"
 		exit 1
diff --git a/git-verify-tag.sh b/git-verify-tag.sh
index 8db7dd0..11ce947 100755
--- a/git-verify-tag.sh
+++ b/git-verify-tag.sh
@@ -38,8 +38,7 @@ trap 'rm -f "$GIT_DIR/.tmp-vtag"' 0
 
 git-cat-file tag "$1" >"$GIT_DIR/.tmp-vtag" || exit 1
 
-cat "$GIT_DIR/.tmp-vtag" |
-sed '/-----BEGIN PGP/Q' |
+sed '/-----BEGIN PGP/Q' "$GIT_DIR/.tmp-vtag" |
 gpg --verify "$GIT_DIR/.tmp-vtag" - || exit 1
 rm -f "$GIT_DIR/.tmp-vtag"
 
-- 
1.5.2.1



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Re: [PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[Stephen Rothwell]

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On Tue, 05 Jun 2007 18:34:59 -0700 Josh Triplett <josh@freedesktop.org> wrote:
>
> -commits=$(cat ../revs | wc -l | tr -d " ")
> +commits=$(wc -l ../revs | tr -d " ")

This is not equivalent, you probably wanted:

commits=$(wc -l <../revs | tr -d " ")

Cheers,
Stephen Rothwell

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Re: [PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[Michael Poole]

Stephen Rothwell writes:

> On Tue, 05 Jun 2007 18:34:59 -0700 Josh Triplett <josh@freedesktop.org> wrote:
>>
>> -commits=$(cat ../revs | wc -l | tr -d " ")
>> +commits=$(wc -l ../revs | tr -d " ")
>
> This is not equivalent, you probably wanted:
>
> commits=$(wc -l <../revs | tr -d " ")

Which relevant version(s) of wc do not accept filename arguments?
POSIX[1] seems to specify it.  Or do you mean that there is some
subtle difference in its processing of stdin vs specified files?

[1]- http://www.opengroup.org/onlinepubs/000095399/utilities/wc.html

Michael Poole

Re: [PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[Martin Langhoff]

On 6/6/07, Michael Poole <mdpoole@troilus.org> wrote:
> Stephen Rothwell writes:
>
> > On Tue, 05 Jun 2007 18:34:59 -0700 Josh Triplett <josh@freedesktop.org> wrote:
> >>
> >> -commits=$(cat ../revs | wc -l | tr -d " ")
> >> +commits=$(wc -l ../revs | tr -d " ")
> >
> > This is not equivalent, you probably wanted:
> >
> > commits=$(wc -l <../revs | tr -d " ")
>
> Which relevant version(s) of wc do not accept filename arguments?
> POSIX[1] seems to specify it.  Or do you mean that there is some
> subtle difference in its processing of stdin vs specified files?

Josh is right. The output *is* different because it contains the
filename as well. See

  $ wc < .gitk | tr -d " "
  2177551
  $ wc .gitk | tr -d " "
  2177551.gitk

cheers


m

Re: [PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[Stephen Rothwell]

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On Wed, 6 Jun 2007 15:58:09 +1200 "Martin Langhoff" <martin.langhoff@gmail.com> wrote:
>
> Josh is right. The output *is* different because it contains the
  ^^^^
My name is Stephen  :-) and that is indeed what I meant.

Cheers,
Stephen Rothwell

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Re: [PATCH] Remove useless uses of cat, and replace with filename arguments or redirection

[Martin Langhoff]

On 6/6/07, Stephen Rothwell <git@ozlabs.org> wrote:
> On Wed, 6 Jun 2007 15:58:09 +1200 "Martin Langhoff" <martin.langhoff@gmail.com> wrote:
> >
> > Josh is right. The output *is* different because it contains the
>   ^^^^
> My name is Stephen  :-) and that is indeed what I meant.

Sorry! Cross-eyed over the email thread, but not over posix behaviour ;-)

...cleans those glasses now


martin