# is it possible filter the revision history of a single file into another repository? 8 messages from 2008-12-18 to 2008-12-19. Participants: Whit Armstrong, Thomas Jarosch, Sverre Rabbelier. Thread: https://gitlist.dev/t/16783 ## Whit Armstrong, 2008-12-18 13:51 Subject: is it possible filter the revision history of a single file into another repository? Message-ID: <8ec76080812180551p8c97a0dqa2025e67792946c7@mail.gmail.com> URL: https://gitlist.dev/e/8ec76080812180551p8c97a0dqa2025e67792946c7%40mail.gmail.com ``` For instance, if my repository contains foo.c, and 100 other files. I would like to create a new and separate repository containing only the revision history of foo.c. Would someone mind pointing me at some documentation for this procedure if it exists? Thanks very much, Whit ``` ## Thomas Jarosch, 2008-12-18 14:04 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: <200812181504.02105.thomas.jarosch@intra2net.com> URL: https://gitlist.dev/e/200812181504.02105.thomas.jarosch%40intra2net.com In-Reply-To: <8ec76080812180551p8c97a0dqa2025e67792946c7@mail.gmail.com> ``` On Thursday, 18. December 2008 14:51:12 Whit Armstrong wrote: > For instance, if my repository contains foo.c, and 100 other files. > > I would like to create a new and separate repository containing only > the revision history of foo.c. > > Would someone mind pointing me at some documentation for this > procedure if it exists? This worked for me: git filter-branch --tag-name-filter cat --index-filter \ 'git ls-files -s |grep -P "\t(DIR1|DIR2)" \ |GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index --index-info && mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE' -- --all Run "git ls-files -s" to see the output format. Replace the "DIR1|DIR2" with "foo.c". Later on you might want to remove empty commits from the history: git filter-branch --tag-name-filter cat --commit-filter 'if [ z$1 = z`git rev-parse $3^{tree}` ]; then skip_commit "$@"; else git commit-tree "$@"; fi' "$@" -- --all If you want to run two filter-branch commands in a row or you want to free up the space in .git afterwards: - git for-each-ref --format='%(refname)' refs/original | xargs -i git update-ref -d {} - git reflog expire --expire=0 --all - git repack -a -d - git prune Cheers, Thomas ``` ## Sverre Rabbelier, 2008-12-18 14:15 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: URL: https://gitlist.dev/e/bd6139dc0812180615v34d9aa7dj4b24ddf049b5615e%40mail.gmail.com In-Reply-To: <8ec76080812180551p8c97a0dqa2025e67792946c7@mail.gmail.com> ``` On Thu, Dec 18, 2008 at 14:51, Whit Armstrong wrote: > For instance, if my repository contains foo.c, and 100 other files. > > I would like to create a new and separate repository containing only > the revision history of foo.c. > > Would someone mind pointing me at some documentation for this > procedure if it exists? I think "git filter-branch" is what you need. Have it filter out changes to files but foo.c, and then remove all empty commits. -- Cheers, Sverre Rabbelier ``` ## Whit Armstrong, 2008-12-18 14:19 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: <8ec76080812180619k78a28e30t591b514148202869@mail.gmail.com> URL: https://gitlist.dev/e/8ec76080812180619k78a28e30t591b514148202869%40mail.gmail.com In-Reply-To: <200812181504.02105.thomas.jarosch@intra2net.com> ``` thanks, I will give this a try. On Thu, Dec 18, 2008 at 9:04 AM, Thomas Jarosch wrote: > On Thursday, 18. December 2008 14:51:12 Whit Armstrong wrote: >> For instance, if my repository contains foo.c, and 100 other files. >> >> I would like to create a new and separate repository containing only >> the revision history of foo.c. >> >> Would someone mind pointing me at some documentation for this >> procedure if it exists? > > This worked for me: > > git filter-branch --tag-name-filter cat --index-filter \ > 'git ls-files -s |grep -P "\t(DIR1|DIR2)" \ > |GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index --index-info && > mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE' -- --all > > Run "git ls-files -s" to see the output format. > Replace the "DIR1|DIR2" with "foo.c". > > Later on you might want to remove empty commits from the history: > git filter-branch --tag-name-filter cat --commit-filter 'if [ z$1 = z`git rev-parse $3^{tree}` ]; then skip_commit "$@"; else git commit-tree "$@"; fi' "$@" -- --all > > If you want to run two filter-branch commands in a row > or you want to free up the space in .git afterwards: > > - git for-each-ref --format='%(refname)' refs/original | xargs -i git update-ref -d {} > - git reflog expire --expire=0 --all > - git repack -a -d > - git prune > > Cheers, > Thomas > > ``` ## Whit Armstrong, 2008-12-18 19:51 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: <8ec76080812181151y4a5a6f5cna57785c935032e77@mail.gmail.com> URL: https://gitlist.dev/e/8ec76080812181151y4a5a6f5cna57785c935032e77%40mail.gmail.com In-Reply-To: <8ec76080812180619k78a28e30t591b514148202869@mail.gmail.com> ``` Sorry, seem to be getting this error: `/home/whit/dvl/risk.metrics.utils/RiskMetrics/.git-rewrite/t/../index.new': No such file or directory do I need to set up the index file first? Is there a good site that documents this procedure? [whit@linuxsvr RiskMetrics]$ git filter-branch --tag-name-filter cat --index-filter \ > 'git ls-files -s |grep -P "riskmetrics.rb" \ > |GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index --index-info && > mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE' -- --all Rewrite 8f1a0eaae033d109f4a3a4b410bd8e04dd9997db (1/481)mv: cannot stat `/home/whit/dvl/risk.metrics.utils/RiskMetrics/.git-rewrite/t/../index.new': No such file or directory index filter failed: git ls-files -s |grep -P "riskmetrics.rb" \ |GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index --index-info && mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE [whit@linuxsvr RiskMetrics]$ On Thu, Dec 18, 2008 at 9:19 AM, Whit Armstrong wrote: > thanks, I will give this a try. > > On Thu, Dec 18, 2008 at 9:04 AM, Thomas Jarosch > wrote: >> On Thursday, 18. December 2008 14:51:12 Whit Armstrong wrote: >>> For instance, if my repository contains foo.c, and 100 other files. >>> >>> I would like to create a new and separate repository containing only >>> the revision history of foo.c. >>> >>> Would someone mind pointing me at some documentation for this >>> procedure if it exists? >> >> This worked for me: >> >> git filter-branch --tag-name-filter cat --index-filter \ >> 'git ls-files -s |grep -P "\t(DIR1|DIR2)" \ >> |GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index --index-info && >> mv $GIT_INDEX_FILE.new $GIT_INDEX_FILE' -- --all >> >> Run "git ls-files -s" to see the output format. >> Replace the "DIR1|DIR2" with "foo.c". >> >> Later on you might want to remove empty commits from the history: >> git filter-branch --tag-name-filter cat --commit-filter 'if [ z$1 = z`git rev-parse $3^{tree}` ]; then skip_commit "$@"; else git commit-tree "$@"; fi' "$@" -- --all >> >> If you want to run two filter-branch commands in a row >> or you want to free up the space in .git afterwards: >> >> - git for-each-ref --format='%(refname)' refs/original | xargs -i git update-ref -d {} >> - git reflog expire --expire=0 --all >> - git repack -a -d >> - git prune >> >> Cheers, >> Thomas >> >> > ``` ## Thomas Jarosch, 2008-12-19 09:44 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: <200812191044.47830.thomas.jarosch@intra2net.com> URL: https://gitlist.dev/e/200812191044.47830.thomas.jarosch%40intra2net.com In-Reply-To: <8ec76080812181151y4a5a6f5cna57785c935032e77@mail.gmail.com> ``` On Thursday, 18. December 2008 20:51:38 Whit Armstrong wrote: > Sorry, seem to be getting this error: > `/home/whit/dvl/risk.metrics.utils/RiskMetrics/.git-rewrite/t/../index.new' >: No such file or directory > > do I need to set up the index file first? Hmm, I guess you have an empty commit in your repository like I did. This is currently a corner case in update-index, which does not create empty index files. I posted a patch a few days ago and Junio posted an updated version of that. I could send you my version for git 1.6.0.5 if you need it. > Is there a good site that documents this procedure? A good start is the git-filter-branch man page and the mailinglist archive. Thomas ``` ## Whit Armstrong, 2008-12-19 13:08 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: <8ec76080812190508v2ef0f982pab66a698f06a80d5@mail.gmail.com> URL: https://gitlist.dev/e/8ec76080812190508v2ef0f982pab66a698f06a80d5%40mail.gmail.com In-Reply-To: <200812191044.47830.thomas.jarosch@intra2net.com> ``` thanks, Thomas. I could definitely pull from your tree. seems like the path of least resistance to get my repo split. Cheers, Whit On Fri, Dec 19, 2008 at 4:44 AM, Thomas Jarosch wrote: > On Thursday, 18. December 2008 20:51:38 Whit Armstrong wrote: >> Sorry, seem to be getting this error: >> `/home/whit/dvl/risk.metrics.utils/RiskMetrics/.git-rewrite/t/../index.new' >>: No such file or directory >> >> do I need to set up the index file first? > > Hmm, I guess you have an empty commit in your repository like I did. > This is currently a corner case in update-index, which does not create empty > index files. I posted a patch a few days ago and Junio posted an updated > version of that. I could send you my version for git 1.6.0.5 if you need it. > >> Is there a good site that documents this procedure? > > A good start is the git-filter-branch man page and the mailinglist archive. > > Thomas > > ``` ## Thomas Jarosch, 2008-12-19 13:17 Subject: Re: is it possible filter the revision history of a single file into another repository? Message-ID: <200812191417.13147.thomas.jarosch@intra2net.com> URL: https://gitlist.dev/e/200812191417.13147.thomas.jarosch%40intra2net.com In-Reply-To: <8ec76080812190508v2ef0f982pab66a698f06a80d5@mail.gmail.com> ``` On Friday, 19. December 2008 14:08:23 Whit Armstrong wrote: > thanks, Thomas. I could definitely pull from your tree. seems like > the path of least resistance to get my repo split. Here's the patch I use for git 1.6.0.5. According to Junio it has the small drawback of always writing out the index, even if there are no changes. If you need an updated patch against HEAD, look for Junio's reply to my patch in the list archive. Enjoy, Thomas Signed-off-by: Thomas Jarosch --- git-1.6.0.5/builtin-update-index.c 2008-12-08 02:21:49.000000000 +0100 +++ git-1.6.0.5.index/builtin-update-index.c 2008-12-13 12:43:14.000000000 +0100 @@ -297,6 +297,8 @@ static void read_index_info(int line_ter struct strbuf buf; struct strbuf uq; + int found_something = 0; + strbuf_init(&buf, 0); strbuf_init(&uq, 0); while (strbuf_getline(&buf, stdin, line_termination) != EOF) { @@ -307,6 +309,8 @@ static void read_index_info(int line_ter unsigned long ul; int stage; + found_something = 1; + /* This reads lines formatted in one of three formats: * * (1) mode SP sha1 TAB path @@ -382,6 +386,11 @@ static void read_index_info(int line_ter bad_line: die("malformed index info %s", buf.buf); } + + /* Force creation of empty index - needed by git filter-branch */ + if (!found_something) + active_cache_changed = 1; + strbuf_release(&buf); strbuf_release(&uq); } ```