pkg_add(1)

NAME
pkg_add - a utility for installing software package distributions.

SYNOPSIS
pkg_add [-vInfRMS] [-t template] [-p prefix] pkg-name [pkg-name ...]

DESCRIPTION
The pkg_add command is used to extract packages that have been previously created with the pkg_create(1) command.

WARNING
Since the pkg_add command may execute scripts or programs contained within a package file, your system may be susceptible to ``trojan horses'' or other subtle attacks from miscreants who create dangerous package files.

You are advised to verify the competence and identity of those who provide installable package files. For extra protection, use the -M flag to extract the package file, and inspect its contents and scripts to insure it poses no danger to your system's integrity. Pay particular attention to any +INSTALL, +DEINSTALL, +REQUIRE or +MTREE_DIRS files, and inspect the +CONTENTS file for @cwd, @mode (check for setuid), @dirrm, @exec, and @unexec directives, and/or use the pkg_info(1) command to examine the package file.

OPTIONS
The following command line arguments are supported.

pkg-name [... pkg-name]
    The named packages are installed. A package name of - will cause pkg_add to read from stdin.

-v  Turns on verbose output. Optional.

-I  If an installation script exists for a given package, do not execute it. Optional.

-n  Don't actually install a package, just report the steps that would be taken if it was. Optional.

-R  Do not record the installation of a package. This means that you cannot deinstall it later, so only use this option if you know what you are doing! Optional.

-f  Forces installation to proceed even if prerequisite packages are not installed or the requirements script fails. Optional.

-p prefix
    Sets prefix as the directory in which to extract files from a package. If a package has set its default directory, it will be overridden by this flag. Note that only the first @cwd directive will be replaced, since pkg_add has no way of knowing which directory settings are relative and which are absolute. It is rare, in any case, to see more than one directory transition made, but when such is the case you may then wish to look into the use of the MASTER and SLAVE modes (see the -M and -S options). Optional.

-t template
    Use template as the input to mktemp(3) when creating a ``staging area.'' By default, this is the string /var/tmp/instmp.XXXXXX, but it may be necessary to override it in the situation where space in your /tmp directory is limited. Be sure to leave some number of `X' characters for mktemp(3) to fill in with a unique ID.

    You can get a performance boost by setting the staging area template to reside on the same disk partition as target directories for package file installation; often this is /usr. Optional.

-M  Run in MASTER mode. This is a very specialized mode for running pkg_add and is meant to be run in conjunction with SLAVE mode. When run in this mode, pkg_add does no work beyond extracting the package into a temporary staging area (see the -t option), reading in the packing list, and then dumping it (prefaced by the current staging area) to stdout where it may be filtered by a program such as sed(1). When used in conjunction with SLAVE mode, it allows you to make radical changes to the package structure before acting on its contents.

-S  Run in SLAVE mode. This is a very specialized mode for running pkg_add and is meant to be run in conjunction with MASTER mode. When run in this mode, pkg_add expects the release contents to be already extracted and waiting in the staging area, the location of which is read as a string from stdin. The complete packing list is also read from stdin, and the contents then acted on as normal.
On or more pkg-name arguments may be specified, each being either a file containing the package (these usually ending with the ``.tgz'' suffix) or a URL pointing at a file available on an ftp site. Thus you may extract files directly from their anonymous ftp locations (e.g. pkg_add ftp://ftp.freebsd.org/pub/FreeBSD/packages/shells/bash-1.14.4.tgz). Note: If you wish to use ftp in such transfers, set the variable to some value in your environment. Otherwise, the more standard ACTIVE mode may be used. If pkg_add consistently fails to fetch a package from a site known to work, it may be because you have a firewall that demands the usage of ftp.

TECHNICAL DETAILS
pkg_add is fairly simple. It extracts each packages' "packing list" into a special staging directory in /tmp (or $PKG_TMPDIR), parses it, then runs through the following sequence to fully extract the contents:

1.  Check if the package is already recorded as installed. If so, terminate installation.

2.  Scan all the package dependencies (from @pkgdep directives, see pkg_create(1)) and make sure each one is met. If not, print the missing dependencies and terminate the installation.

3.  Search for any @option directives which control how the package is added to the system. At the time of this writing, the only currently implemented option is @option extract-in-place which will cause the package to be extracted direcly into its prefix directory without moving through a staging area in /tmp.

4.  If @option extract-in-place is enabled, the package is now extracted directly into its final location, otherwise it is extracted into the staging area.

5.  If the package contains a require file (see pkg_create(1) ), then execute it with the following arguments:
    <pkg-name> INSTALL

    where <pkg-name> is the name of the package in question and INSTALL is simply a keyword denoting that this is an installation requirements check.

6.  If an install script exists for the package, it is then executed with the following arguments:
    <pkg-name> PRE-INSTALL

    where <pkg-name> is the name of the package in question and PRE-INSTALL is a keyword denoting that this is the preinstallation phase.

7.  If @option extract-in-place is not used, then the packing list (this is the +CONTENTS file) is now used as a guide for moving (or copying, as necessary) files from the staging area into their final locations.

8.  If the package contains an mtreefile file (see the -m option to pkg_create(1) ), then mtree is invoked as
    mtree -u -f mtreefile -d -e -p prefix

    where prefix is either the prefix specified with the -p flag or, if no -p flag was specified, the name of the first directory named by a @cwd directive within this package.

9.  If an install script exists for the package, it is then executed as
    <script> <pkg-name> POST-INSTALL

    This all allows you to write a single install script that does both ``before and after'' actions.

10. After installation is complete, a copy of the packing list, deinstall script, description, and display files are copied into /var/db/pkg/<pkg-name> for subsequent possible use by pkg_delete(1). Any package dependencies are recorded in the other packages' /var/db/pkg/<other-pkg>/+REQUIRED_BY file (if the environment variable PKG_DBDIR is set, this overrides the /var/db/pkg/ path shown above).

11. Finally, the staging area is deleted and the program terminates.

All the scripts are called with the environment variable PKG_PREFIX set to the installation prefix (see the -p option above). This allows a package author to write a script that reliably performs some action on the directory where the package is installed, even if the user might change it with the -p flag to pkg_add.

SEE ALSO
pkg_info(1), mktemp(3), sysconf(3), mtree(8), pkg_create(1), pkg_delete(1).

AUTHORS
Jordan Hubbard
    most of the work
John Kohl
    refined it for NetBSD

BUGS
Hard links between files in a distribution are only preserved if either (1) the staging area is on the same file system as the target directory of all the links to the file, or (2) all the links to the file are bracketed by @cwd directives in the contents file, and and the link names are extracted with a single tar command (not split between invocations due to exec argument-space limitations--this depends on the value returned by sysconf(_SC_ARG_MAX) ).

Sure to be others.