# [PATCH v2] mergetool: use more conservative temporary filenames 6 messages from 2014-10-10 to 2014-10-13. Participants: David Aguilar, Jakub Narębski, Johannes Sixt, Junio C Hamano. Thread: https://gitlist.dev/t/37704 ## David Aguilar, 2014-10-10 08:19 Subject: [PATCH v2] mergetool: use more conservative temporary filenames Message-ID: <1412929187-57936-1-git-send-email-davvid@gmail.com> URL: https://gitlist.dev/e/1412929187-57936-1-git-send-email-davvid%40gmail.com ``` Avoid filenames with multiple dots so that overly-picky tools do not misinterpret their extension. Previously, foo/bar.ext in the worktree would result in e.g. ./foo/bar.ext.BASE.1234.ext This can be improved by having only a single .ext and using underscore instead of dot so that the extension cannot be misinterpreted. The resulting path becomes: ./foo/bar_BASE_1234.ext Suggested-by: Sergio Ferrero Helped-by: Junio C Hamano Signed-off-by: David Aguilar --- Changes since v1 The commit message changed to say "./foo" instead of "foo". The patch now uses Junio's suggestion to minimize variables, and preserves the original leading ./ just in case there are tools that rely on having ./ in front of relative paths. git-mergetool.sh | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/git-mergetool.sh b/git-mergetool.sh index 9a046b7..96a61ba 100755 --- a/git-mergetool.sh +++ b/git-mergetool.sh @@ -228,11 +228,17 @@ merge_file () { return 1 fi - ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')" - BACKUP="./$MERGED.BACKUP.$ext" - LOCAL="./$MERGED.LOCAL.$ext" - REMOTE="./$MERGED.REMOTE.$ext" - BASE="./$MERGED.BASE.$ext" + if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$') + then + ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$') + else + BASE=$MERGED + ext= + fi + BACKUP="./${BASE}_BACKUP_$$$ext" + LOCAL="./${BASE}_LOCAL_$$$ext" + REMOTE="./${BASE}_REMOTE_$$$ext" + BASE="./${BASE}_BASE_$$$ext" base_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}') local_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}') -- 2.1.2.375.gd89e6a9 ``` ## Jakub Narębski, 2014-10-10 11:19 Subject: Re: [PATCH v2] mergetool: use more conservative temporary filenames Message-ID: <5437C0CC.7030102@gmail.com> URL: https://gitlist.dev/e/5437C0CC.7030102%40gmail.com In-Reply-To: <1412929187-57936-1-git-send-email-davvid@gmail.com> ``` David Aguilar wrote: > Avoid filenames with multiple dots so that overly-picky tools do > not misinterpret their extension. > > Previously, foo/bar.ext in the worktree would result in e.g. > > ./foo/bar.ext.BASE.1234.ext > > This can be improved by having only a single .ext and using > underscore instead of dot so that the extension cannot be > misinterpreted. The resulting path becomes: > > ./foo/bar_BASE_1234.ext > > Suggested-by: Sergio Ferrero > Helped-by: Junio C Hamano > Signed-off-by: David Aguilar > --- > + if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$') > + then > + ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$') > + else > + BASE=$MERGED > + ext= > + fi Why use expr and not POSIX shell parameter substitution? BASE=${MERGED%.*} ext=.${MERGED##*.} Or something like that... -- Jakub Narębski ``` ## David Aguilar, 2014-10-10 18:48 Subject: Re: [PATCH v2] mergetool: use more conservative temporary filenames Message-ID: <20141010184834.GB78117@gmail.com> URL: https://gitlist.dev/e/20141010184834.GB78117%40gmail.com In-Reply-To: <5437C0CC.7030102@gmail.com> ``` On Fri, Oct 10, 2014 at 01:19:40PM +0200, Jakub Narębski wrote: > David Aguilar wrote: > >Avoid filenames with multiple dots so that overly-picky tools do > >not misinterpret their extension. > > > >Previously, foo/bar.ext in the worktree would result in e.g. > > > > ./foo/bar.ext.BASE.1234.ext > > > >This can be improved by having only a single .ext and using > >underscore instead of dot so that the extension cannot be > >misinterpreted. The resulting path becomes: > > > > ./foo/bar_BASE_1234.ext > > > >Suggested-by: Sergio Ferrero > >Helped-by: Junio C Hamano > >Signed-off-by: David Aguilar > >--- > > >+ if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$') > >+ then > >+ ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$') > >+ else > >+ BASE=$MERGED > >+ ext= > >+ fi > > Why use expr and not POSIX shell parameter substitution? > > BASE=${MERGED%.*} > ext=.${MERGED##*.} > > Or something like that... Thanks for the sug. My POSIX shell parameter expansion-fu is not super advanced, but if you can help me rework it I'd be happy to reroll. It does seem simple and robust with expr, though. Extending the parameter expansion approach to work in all cases may end up with more complexity than with the expr method, it seems. Here are the use cases: $ MERGED=foo.bar.baz && echo ${MERGED%.*} ${MERGED##*.} foo.bar baz Good. $ MERGED=foo && echo ${MERGED%.*} ${MERGED##*.} foo foo Bad. There's no extension and the substitution doesn't handle it. $ MERGED=foo.bar/baz && echo ${MERGED%.*} ${MERGED##*.} foo bar/baz Bad. There's no extension but the substitution thinks the parent directory's extension-less name is the basename, and thinks that bar/baz is the extension. I am curious to know whether there's a nice and elegant way to do it with shell expansions. Let me know what you think. cheers, -- David ``` ## Johannes Sixt, 2014-10-10 19:54 Subject: Re: [PATCH v2] mergetool: use more conservative temporary filenames Message-ID: <54383975.9080803@kdbg.org> URL: https://gitlist.dev/e/54383975.9080803%40kdbg.org In-Reply-To: <20141010184834.GB78117@gmail.com> ``` Am 10.10.2014 um 20:48 schrieb David Aguilar: > On Fri, Oct 10, 2014 at 01:19:40PM +0200, Jakub Narębski wrote: >> David Aguilar wrote: >>> Avoid filenames with multiple dots so that overly-picky tools do >>> not misinterpret their extension. >>> >>> Previously, foo/bar.ext in the worktree would result in e.g. >>> >>> ./foo/bar.ext.BASE.1234.ext >>> >>> This can be improved by having only a single .ext and using >>> underscore instead of dot so that the extension cannot be >>> misinterpreted. The resulting path becomes: >>> >>> ./foo/bar_BASE_1234.ext >>> >>> Suggested-by: Sergio Ferrero >>> Helped-by: Junio C Hamano >>> Signed-off-by: David Aguilar >>> --- >> >>> + if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$') >>> + then >>> + ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$') >>> + else >>> + BASE=$MERGED >>> + ext= >>> + fi >> >> Why use expr and not POSIX shell parameter substitution? >> >> BASE=${MERGED%.*} >> ext=.${MERGED##*.} >> >> Or something like that... > > Thanks for the sug. > > My POSIX shell parameter expansion-fu is not super advanced, but > if you can help me rework it I'd be happy to reroll. > > It does seem simple and robust with expr, though. Extending the > parameter expansion approach to work in all cases may end up > with more complexity than with the expr method, it seems. > > Here are the use cases: > > $ MERGED=foo.bar.baz && echo ${MERGED%.*} ${MERGED##*.} > foo.bar baz > > Good. > > $ MERGED=foo && echo ${MERGED%.*} ${MERGED##*.} > foo foo > > Bad. > There's no extension and the substitution doesn't handle it. > > $ MERGED=foo.bar/baz && echo ${MERGED%.*} ${MERGED##*.} > foo bar/baz > > Bad. > There's no extension but the substitution thinks the parent directory's > extension-less name is the basename, and thinks that bar/baz is the extension. > > I am curious to know whether there's a nice and elegant way to do it > with shell expansions. Let me know what you think. It's not exactly elegant to do it: First, you extract the last path part: file=${MERGED##*/} Then the directory including the trailing slash: dir=${MERGED%"$file"} Then the basename without an extension: base=${file%.*} Finally the extension including the dot: ext=${file#"$base"} Beware of empty $base and $dir (e.g., for files named .gitignore or so) -- Hannes ``` ## Junio C Hamano, 2014-10-10 21:16 Subject: Re: [PATCH v2] mergetool: use more conservative temporary filenames Message-ID: URL: https://gitlist.dev/e/xmqq38av62x0.fsf%40gitster.dls.corp.google.com In-Reply-To: <5437C0CC.7030102@gmail.com> ``` Jakub Narębski writes: > Why use expr and not POSIX shell parameter substitution? > > BASE=${MERGED%.*} > ext=.${MERGED##*.} > > Or something like that... Because they are insufficient. See David's illustrations for how. Parameter expansion (e.g. ${parameter%word}) is fine for the simplest cases (e.g. you know there is .c suffix to the $string and want to strip it out) but not sufficient for other cases (e.g. you may not even know if there is any suffix). You can deconstruct your regexps manually and use conditional if/else/fi if you are unable to use expr, but I do not see how it buys us anything. ``` ## Junio C Hamano, 2014-10-13 19:30 Subject: Re: [PATCH v2] mergetool: use more conservative temporary filenames Message-ID: URL: https://gitlist.dev/e/xmqqfver3gy6.fsf%40gitster.dls.corp.google.com In-Reply-To: <1412929187-57936-1-git-send-email-davvid@gmail.com> ``` David Aguilar writes: > Avoid filenames with multiple dots so that overly-picky tools do > not misinterpret their extension. > > Previously, foo/bar.ext in the worktree would result in e.g. > > ./foo/bar.ext.BASE.1234.ext > > This can be improved by having only a single .ext and using > underscore instead of dot so that the extension cannot be > misinterpreted. The resulting path becomes: > > ./foo/bar_BASE_1234.ext > > Suggested-by: Sergio Ferrero > Helped-by: Junio C Hamano > Signed-off-by: David Aguilar > --- > Changes since v1 > > The commit message changed to say "./foo" instead of "foo". > > The patch now uses Junio's suggestion to minimize variables, > and preserves the original leading ./ just in case there are > tools that rely on having ./ in front of relative paths. ;-) Perhaps together with the "allow temporary directory" patch, we would want to have a few tests for these changes? > > git-mergetool.sh | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/git-mergetool.sh b/git-mergetool.sh > index 9a046b7..96a61ba 100755 > --- a/git-mergetool.sh > +++ b/git-mergetool.sh > @@ -228,11 +228,17 @@ merge_file () { > return 1 > fi > > - ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')" > - BACKUP="./$MERGED.BACKUP.$ext" > - LOCAL="./$MERGED.LOCAL.$ext" > - REMOTE="./$MERGED.REMOTE.$ext" > - BASE="./$MERGED.BASE.$ext" > + if BASE=$(expr "$MERGED" : '\(.*\)\.[^/]*$') > + then > + ext=$(expr "$MERGED" : '.*\(\.[^/]*\)$') > + else > + BASE=$MERGED > + ext= > + fi > + BACKUP="./${BASE}_BACKUP_$$$ext" > + LOCAL="./${BASE}_LOCAL_$$$ext" > + REMOTE="./${BASE}_REMOTE_$$$ext" > + BASE="./${BASE}_BASE_$$$ext" > > base_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}') > local_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}') ```