###################################################################### Cvs::Trigger 0.03 ###################################################################### NAME Cvs::Trigger - Argument parsers for CVS triggers SYNOPSIS # CVSROOT/commitinfo DEFAULT /path/trigger # /path/trigger use Cvs::Trigger; my $c = Cvs::Trigger->new(); my $args = $c->parse("commitinfo"); if( $args->{repo_dir} =~ m#/secret$#) { die "You can't check stuff into the secret project"; } for my $file (@{ $args->{files} }) { if( $file =~ /\.doc$/ ) { die "Sorry, we don't allow .doc files in CVS"; } } DESCRIPTION CVS provides three different hooks to intercept check-ins. They can be used to approve/reject check-ins or to take action, like logging the check-in in a database. "commitinfo" Gets executed before the check-in happens. If it returns a false value (usually caused by calling "die()"), the check-in gets rejected. The following entry in the CVS admin file "commitinfo" calls the hook for all check-ins: # CVSROOT/commitinfo ALL /path/cvstrig The corresponding script, "/path/cvstrig", parses the arguments which "cvs" passes to them: # /path/cvstrig use Cvs::Trigger; my $c = Cvs::Trigger->new(); my $args = $c->parse("commitinfo"); Note that you need to specify the hook name to the "parse" method, because CVS provides the different hooks with different parameters. In case of the "commitinfo" hook, the following parameters are available as keys into the has referenced by $args: "repo_dir" Full path to the repository directory where the check-in happens, e.g. "/cvsroot/foo/bardir". "files" Reference to an array of filenames involved the check-in. No path information is provided, all files are relative to the "repo_dir" directory. "opts" Additionally, optional parameters passed to the trigger script are available with this parameter. Note that the number of these parameters needs to be passed to the "parse" method: # CVSROOT/commitinfo ALL /path/cvstrig foo bar # /path/cvstrig use Cvs::Trigger; my $c = Cvs::Trigger->new(); my $args = $c->parse("commitinfo", { n_opt_args => 2 }); # => "foo-bar" print join('-', @{ $args->{opts} }), "\n"; "verifymsg" Gets executed right after the user entered the check-in message. Based on the message text, the check-in can be approved or rejected. This hook is typically used to enforce a certain format or content of the log message provided by the user. Here's an example that checks if the check-in message references a bug number: # CVSROOT/verifymsg DEFAULT /path/checkin-verifier # /path/checkin-verifier #!/usr/bin/perl use Cvs::Trigger; my $c = Cvs::Trigger->new(); my $args = $c->parse("verifymsg"); if( $args->{message} =~ m(fixes bug #)) { die "No bug number specified"; } "verifymsg" provides the message, accessible by the "message" key in the hash ref returned by the "parse" method. Additionally, the "opts" key provides a list of optional parameters passed to the script (check "commitinfo" for details). "loginfo" Gets executed after the check-in succeeded. It doesn't matter if the corresponding script fails or not, the check-in has already happend by the time it gets called. An entry like DEFAULT /path/string will call the loginfo script with the following data on STDIN: Update of /cvsroot/m/a In directory mybox:/local_root/m/a Modified Files: a1.txt Log Message: Fixing some bug, forgot which one. Yay! There's no need to parse this, though, "Cvs::Trigger" will do that for you. The following hash keys are available: "repo_dir" Full path to the repository directory where the check-in happens, e.g. "/cvsroot/foo/bardir". "host" Name of the host where the check-in has been initiated. "local_dir" The directory in the user's workspace where the check-in got initiated. "message" Check-in message. "files" Reference to an array of filenames involved the check-in. No path information is provided, all files are relative to the "repo_dir" directory. "loginfo" scripts can get additional data from "cvs". For this to happen, the call syntax in the "loginfo" administration file needs to change to this format: DEFAULT ((echo %{sVv}; cat) | /path/script) The first line piped into the script's STDIN then consists of the file name, the previous and the new revision number, all space-separated (oh well, this seems to have been invented before spaces in file names came around): module/path file1.txt,1.3,1.4 file2,1.1,1.2 Update of /tmp/RgNSQ4Yomr/cvsroot/module/path In directory mybox:/tmp/RgNSQ4Yomr/local_root/module/path Modified Files: file1.txt file2.txt Log Message: Here are my check-in notes. In order to parse this enhanced format, the call to "Cvs::Trigger"'s "parse" method needs to be modified: use Cvs::Trigger; my $c = Cvs::Trigger->new(); my $args = $c->parse("verifymsg", { rev_fmt => "sVv" }); The result in args will then store the file names and their revisions under the "revs" key: use Data::Dumper; print Dumper($args->{revs}); # $VAR1 = { file1.txt => [1.3, 1.4] file2.txt => [1.1, 1.2] } Use the same script for multiple hooks You can call the same trigger script in multiple hooks. Since the parameters passed to the script vary from hook to hook, the easiest solution is to pass the hook name on to the script, so that it can switch the command argument parser accordingly: # CVSROOT/commitinfo DEFAULT /path/trigger commitinfo # CVSROOT/verifymsg DEFAULT /path/trigger verifymsg #!/usr/bin/perl use Cvs::Trigger; my $c = Cvs::Trigger->new(); my $hook = shift; # First argument specifies the parser my $args = $c->parse( $hook ); if( $hook eq "verifymsg" ) { if( $args->{message} =~ m(fixes bug #)) { die "No bug number specified"; } } elsif( $hook eq "commitinfo" ) { if( $args->{repo_dir} =~ m#/secret$#) { die "You can't check stuff into the secret project"; } } Remember fields by caching THIS FEATURE IS EXPERIMENTAL. USE AT YOUR OWN RISK. If you want to make a decision based on both the file name and the check-in message, none of the hooks provides all necessary information in one swoop. If, say, ".c" files need a bug number in their check-in message and ".txt" don't, here's a tricky way to forward the filenames parsed by "commitinfo" to the "verifymsg" hook, which has the check-in message available: # CVSROOT/commitinfo DEFAULT /path/trigger commitinfo # CVSROOT/verifymsg DEFAULT /path/trigger verifymsg #!/usr/bin/perl use Cvs::Trigger; # Turn on the cache my $c = Cvs::Trigger->new( cache => 1 ); my $hook = shift; # First argument specifies the parser my $args = $c->parse( $hook ); if( $hook eq "verifymsg" ) { # We're in verifymsg now, but the cache still holds the file # names obtained in the commitinfo phase if( grep { /\.c$/ } @{ $args->{cache}->{files} } and $args->{message} =~ m(fixes bug #) ) { die "No bug number specified in .c file"; } } Caching has a couple of gotchas, though. First, items can only stay in the cache for a limited time, to avoid a cache overflow with many simultaneous checkins going on. However, the time span between "commitinfo" and "verifymsg" can hardly be estimated accurately. What if someone types "cvs commit" and then goes to lunch? The editor window will stay open, and if the message gets saved a couple of hours later, the cache still needs to hold a copy of the "commitinfo" data. Deleting the cache data once "verifymsg" is done with it doesn't work either. If you type "cvs commit" in a directory with multiple subdirectories, both the "commitinfo" and "verifymsg" will get called for each subdirectory containing modified files. "Cvs::Trigger" therefore maintains a TTL (time to live) counter to keep track of how many instances of "verifymsg" are still going to read it. Bottom line: The cache entry will be deleted once the last "verifymsg" instance is done with it. Nevertheless, determining the cache timeout is a delicate issue. The default values are set as follows: # Turn on the cache my $c = Cvs::Trigger->new( cache => 1, cache_default_expires_in => 3600, cache_auto_purge_interval => 1800, cache_namespace => "cvs", ); Therefore, the cache will expire entries after an hour and it will run the check/prune procedure every half hour. To set different values, simply call "new" with different parameters. The cache namespace can also be configured, see the Cache::Cache manual page for details. The cache makes use of the fact that the "commitinfo" and "verifymsg" scripts are run by processes sharing the same parent pid (ppid). The cache indexes its data using this pid value. If the operating system reuses the same pid within the expiration timeframe, a clash will occur. TODO List * Try filenames with commas, spaces, and newlines * tests for optional arguments * methods vs. hash access * no STDIN on loginfo => hangs SEE ALSO http://ximbiot.com/cvs/wiki/index.php?title=CVS--Concurrent_Versions_Sys tem_v1.12.12.1:_Reference_manual_for_Administrative_files#SEC184 LEGALESE Copyright 2006 by Mike Schilli, all rights reserved. This program is free software, you can redistribute it and/or modify it under the same terms as Perl itself. AUTHOR 2006, Mike Schilli