Copy_db

NAME

copy_db -- a garbage collecting gap4 database copier and merger

SYNOPSIS

copy_db [-v] from.vers ... to.vers

DESCRIPTION

Copy_db copies one or more gap4 databases to a new name by physically extracting the information from the first databases and writing it to the last database listed on the command line. This operation can be considered analogous to copying files into a directory. This is slower than a direct cp command, but has the advantage of merging several databases together and the resulting database will have been garbage collected. That is, any fragmentation in the original databases is removed (as much as is possible).

NOTE: Care should be taken when merging database. No checks are performed to make sure that the databases do not already contain the same readings. Thus attempting to copy the same database several times will cause problems later on. No merging of vector, clone or template information is performed either.

OPTIONS

-v

Enable verbose output. This gives a running summary of the current piece of information being copied.

EXAMPLES

To merge database X with database Y to give a new database Z use:

copy_db X.0 Y.0 Z.0

NOTES

To copy a database quickly without garbage collecting the UNIX cp command can be used as follows. This copies version F of database DB to version T of database XYZZY.

cp DB.F XYZZY.T; cp DB.F.aux XYZZY.T.aux

Care must be taken to check for the busy file (`DB.F.BUSY') before making the copy. If the database is written to during the operation of the copy command then the new database may be corrupted.