.TH zpm-gc 8 2018-12-10 "ZPM 0.4"
.SH NAME
zpm-gc \- garbage collect a database
.SH SYNOPSIS
.B zpm gc [-f \fIdb\fB] [-cCP] [-l retention] [-n retention]
.SH DESCRIPTION
\fBzpm-gc\fR removes unneeded or unwanted elements from a zpm database.
Actions taken will be logged in the database and written to stdout.
Each action is described below.
.SS Old packages
Unused packages will be removed, unless they need to be retained to keep a
library installed, or if they are within the keep target.  By default, two old
versions of a package will be kept.  This phase is run by default,
but can be suppressed with the \-P option.  The keep target can
be set with the -k option or the ZPM_KEEP_PACKAGES environment
variable.  If both are used, the command line option takes precedence.
.PP
Packages kept by the keep target do not include packages otherwise retained for
library dependencies, so it is possible that more than the keep target older
packages will be retained.  Only packages in an "updated" or "removed" status
are eligible for garbage collection, so an admin can keep any arbitrary package
from being garbage collected by setting the status of the package to some other
value.
.SS Log entries
Old log entries can be removed by passing the \-l option.  The -l
option takes an argument specifying which log entries to delete.
.SS Notes
Notes can be removed with the \-n option.
.SS Unreferenced file content
File content unreferenced by either a package, note, or script
will be removed by default.  This action can be suppressed with \-C.
.SS Package file content
File content belonging to packages can be removed with the \-F option.
This is not done by default, and the action can be restricted to
a specific package with the \-p option.
.SS Compact
Re-write the database file out completely to minimize the amount
of disk space it uses.  This option can take a few minutes
for large (gigabyte sized) databases, and is not run by default.
It can be enabled with the \-c option.
.SH OPTIONS
.TP
\-f \fIdbfile\fR
Use \fIdbfile\fR as the database to run against, instead of the default.
.TP
\-l \fIretention\fR
Delete old logentries that correspond to the retention.
A retention starting with a '+' is taken as the number of days to retain.
A retention containing only digits is taken as a number of log entries to
retain, anything else is interpreted as a timestamp.
.TP
\-n \fIretention\fR
Delete old notes that correspond to the retention.
A retention is interpreted the same way as for the \-l option.
.TP
\-z
Zero out the set of actions to preform.
Specific actions can be specified as options after the \-z.
.TP
\-k \fIn\fR
Set the number of old packages to retain to \fIn\fR.  These are in addition to
any packages retained because they contain libraries that are still needed.
.SH EXAMPLES
.PP
.nf
zpm-gc
.fi
.SH EXIT STATUS
0 if successful, non-zero if there was an error
.SH FILES
None
.SH ENVIRONMENT
ZPMDB ZPM_KEEP_PACKAGES
.SH AUTHOR
Nathan Wagner
.SH SEE ALSO
.BR zpm (8)
.BR zpm-log (8)