The cvswrappers file
====================

   Wrappers allow you to set a hook which transforms files on their way
in and out of CVS.

   The file `cvswrappers' defines the script that will be run on a file
when its name matches a regular expresion. There are two scripts that
can be run on a file or directory. One script is executed on the
file/directory before being checked into the repository (this is denoted
with the `-t' flag) and the other when the file is checked out of the
repository (this is denoted with the `-f' flag).  The `-t'/`-f' feature
does not work with client/server CVS.

   The `cvswrappers' also has a `-m' option to specify the merge
methodology that should be used when the file is updated.  `MERGE'
means the usual CVS behavior: try to merge the files (this generally
will not work for binary files).  `COPY' means that `cvs update' will
merely copy one version over the other, and require the user using
mechanisms outside CVS, to insert any necessary changes.  The `-m'
wrapper option only affects behavior when merging is done on update; it
does not affect how files are stored.  See See Binary files, for
more on binary files.

   The basic format of the file `cvswrappers' is:

     wildcard     [option value][option value]...
     
     where option is one of
     -f           from cvs filter         value: path to filter
     -t           to cvs filter           value: path to filter
     -m           update methodology      value: MERGE or COPY
     -k           keyword expansion       value: expansion mode
     
     and value is a single-quote delimited value.

     *.nib    -f 'unwrap %s' -t 'wrap %s %s' -m 'COPY'
     *.c      -t 'indent %s %s'

The above example of a `cvswrappers' file states that all
files/directories that end with a `.nib' should be filtered with the
`wrap' program before checking the file into the repository. The file
should be filtered though the `unwrap' program when the file is checked
out of the repository. The `cvswrappers' file also states that a `COPY'
methodology should be used when updating the files in the repository
(that is no merging should be performed).

   The last example line says that all files that end with a `*.c'
should be filtered with `indent' before being checked into the
repository. Unlike the previous example no filtering of the `*.c' file
is done when it is checked out of the repository.

The `-t' filter is called with two arguments, the first is the name of
the file/directory to filter and the second is the pathname to where
the resulting filtered file should be placed.

The `-f' filter is called with one argument, which is the name of the
file to filter from. The end result of this filter will be a file in
the users directory that they can work on as they normally would.

   Note that the `-t'/`-f' features do not conveniently handle one
portion of CVS's operation: determining when files are modified.  CVS
will still want a file (or directory) to exist, and it will use its
modification time to determine whether a file is modified.  If CVS
erroneously thinks a file is unmodified (for example, a directory is
unchanged but one of the files within it is changed), you can force it
to check in the file anyway by specifying the `-f' option to `cvs
commit' (see commit options.).

   For another example, the following command imports a directory,
treating files whose name ends in `.exe' as binary:

     cvs import -I ! -W "*.exe -k 'b'" first-dir vendortag reltag