REPOCUTTER(1)

NAME
repocutter - surgical and filtering operations on Subversion dump files

SYNOPSIS

repocutter [-q] [-d] [-i 'filename'] [-r 'selection'] 'subcommand'

DESCRIPTION

This program does surgical and filtering operations on Subversion dump files. While it is is not as flexible as reposurgeon(1), it can perform Subversion-specific transformations that reposurgeon cannot, and can be useful for processing Subversion repositories into a form suitable for conversion. Also, it supports the version 3 dumpfile format, which reposurgeon does not.

In all commands, the -r (or --range) option limits the selection of revisions over which an operation will be performed. Usually it behaves like an implied select on the revision output range. A selection consists of one or more comma-separated ranges. A range may consist of an integer revision number or the special name HEAD for the head revision. Or it may be a colon-separated pair of integers, or an integer followed by a colon followed by HEAD.

Normally, each subcommand produces a progress spinner on standard error; each turn means another revision has been filtered. The -q (or --quiet) option suppresses this.

The -d option enables debug messages on standard error. These are probably only of interest to repocutter developers.

The -i option sets the input source to a specified filename. This is primarily useful when running the program under a debugger. When this option is not present the program expects to read a stream from standard input.

Generally, if you need to use this program at all, you will find that you need to pipe your dump file through multiple instances of it doing one kind of operation each. This is not as expensive as it sounds; with the exception of the reduce subcommand, the working set of this program is bounded by the size of the the largest single blob plus its metadata. It does not need to hold the entire repo metadata in memory.

The following subcommands are available:

help
    Without arguments, list available commands. With a command-name argument, show detailed help for that subcommand.

The 'deselect' subcommand selects a range and permits only revisions NOT in that range to pass to standard output.

deselect
    The 'deselect' subcommand selects a range and permits only revisions not in that range to pass to standard output.

expunge
    Delete all operations with Node-path headers matching specified Go regular expressions. Any revision left with no Node records after this filtering has its Revision record removed as well.

log
    Generate a log report, same format as the output of svn log on a repository, to standard output.

obscure
    Replace path segments and committer IDs with arbitrary but consistent names in order to obscure them. The replacement algorithm is tuned to make the replacements readily distinguishable by eyeball.

pathrename
    Modify Node-path and Node-copyfrom-path headers matching a specified regular expression; replace with a given string. The string may contain references to parenthesized portions of the pattern - note, these must be Go-style references led by $, not by a backslash as in reposurgeon itself. See the embedded help for syntax details.

pop
    Pop initial segment off each path. May be useful after a sift command to turn a dump from a subproject stripped from a dump for a multiple-project repository into the normal form with trunk/tags/branches at the top level.

propset
    Set a property to a value. May be restricted by a revision selection. You may specify multiple property settings. See the embedded help for syntax details.

propdel
    Delete the named property. May be restricted by a revision selection. You may specify multiple properties to be deleted. See the embedded help for syntax details.

proprename
    Rename a property. May be restricted by a revision selection. You may specify multiple properties to be renamed. See the embedded help for syntax details.

reduce
    Strip revisions out of a dump so the only parts left those likely to be relevant to a conversion problem. See the embedded help for syntax details and the relevance filter.

renumber
    Renumber all revisions, patching Node-copyfrom headers as required. Any selection option is ignored. Takes no arguments. The -b option set the base to renumber, defaulting to 0.

replace
    Perform a regular expression search/replace on blog content. The first character of the argument (normally /) is treadted as the end delimiter for the regulat-expression and replacement parts.

see
    Render a very condensed report on the repository node structure, mainly useful for examining strange and pathological repositories. File content is ignored. You get one line per repository operation, reporting the revision, operation type, file path, and the copy source (if any). Directory paths are distinguished by a trailing slash. The 'copy' operation is really an 'add' with a directory source and target; the display name is changed to make them easier to see. Additionally, any property settings on a node are dumped immediately after it.

select
    The 'select' subcommand selects a range and permits only revisions in that range to pass to standard output. A range beginning with 0 includes the dumpfile header.

setlog
    Replace the log entries in the input dumpfile with the corresponding entries in a specified file, which should be in the format of an svn log output. Replacements may be restricted to a specified range. See the embedded help for syntax details.

sift
    Delete all operations with Node-path headers not matching specified Go regular expressions (opposite of 'expunge'). Any revision left with no Node records after this filtering has its Revision record removed as well.

strip
    Replace content with unique generated cookies on all node paths matching the specified regular expressions; if no expressions are given, match all paths. Useful when you need to examine a particularly complex node structure.

swap
    Swap the top two components of every path. This is sometimes useful when converting a multi-project Subversion repository that has normal trunk/branch/tag structure under each top-level directory (of course the alternative is to break it into components using multiple strip operations).

testify
    Replace commit timestamps with a monotonically increasing clock tick starting at the Unix epoch and advancing by 10 seconds per commit. Replace all attributions with 'fred'. Discard the repository UUID. Use this to neutralize procedurally-generated streams so they can be compared.

HISTORY

Under the name "svncutter", an ancestor of this program traveled in the 'contrib/' director of the Subversion distribution. It had functional overlap with reposurgeon(1) because it was directly ancestral to that code. It was moved to the reposurgeon(1) distribution in January 2016. This program was ported from Python to Go in August 2018, at which time the obsolete "squash" command was retired. The syntax of regular expressions in the pathrename command changed at that time.

The reason for the partial functional overlap between repocutter and reposurgeon is that repocutter was first written earlier and became a testbed for some of the design concepts in reposurgeon. After reposurgeon was written, the author learned that it could not naturally support some useful operations very specific to Subversion, and enhanced repocutter to do those.

BUGS

There is one regression since the Python version: repocutter no longer recognizes Macintosh-style line endings consisting of a carriage return only. This may be addressed in a future version.

SEE ALSO

reposurgeon(1).

EXAMPLE

Suppose you have a Subversion repository with the following semi-pathological structure:

    Directory1/ (with unrelated content)
    Directory2/ (with unrelated content)
    TheDirIWantToMigrate/
                    branches/
                                   crazy-feature/
                                                   UnrelatedApp1/
                                                   TheAppIWantToMigrate/
                    tags/
                                   v1.001/
                                                   UnrelatedApp1/
                                                   UnrelatedApp2/
                                                   TheAppIWantToMigrate/
                    trunk/
                                   UnrelatedApp1/
                                   UnrelatedApp2/
                                   TheAppIWantToMigrate/

You want to transform the dump file so that TheAppIWantToMigrate can be subject to a regular branchy lift. A way to dissect out the code of interest would be with the following series of filters applied:

    repocutter expunge '^Directory1' '^Directory2'
    repocutter pathrename '^TheDirIWantToMigrate/' ''
    repocutter expunge '^branches/crazy-feature/UnrelatedApp1/
    repocutter pathrename 'branches/crazy-feature/TheAppIWantToMigrate/' 'branches/crazy-feature/'
    repocutter expunge '^tags/v1.001/UnrelatedApp1/'
    repocutter expunge '^tags/v1.001/UnrelatedApp2/'
    repocutter pathrename '^tags/v1.001/TheAppIWantToMigrate/' 'tags/v1.001/'
    repocutter expunge '^trunk/UnrelatedApp1/'
    repocutter expunge '^trunk/UnrelatedApp2/'
    repocutter pathrename '^trunk/TheAppIWantToMigrate/' 'trunk/'

LIMITATIONS

The sift and expunge operations can produce output dumps that are invalid. The problem is copyfrom operations (Subversion branch and tag creations). If an included revision includes a copyfrom reference to an excluded one, the reference target won’t be in the emitted dump; it won’t load correctly in either Subversion or reposurgeon. The revision number in a copyfrom header pointing to a missing revision will be zero. Attempts to be clever about this won’t work; the problem is inherent in the data model of Subversion.

AUTHOR

Eric S. Raymond <This tool is distributed with reposurgeon; see the