path: root/debhelper.1

.TH DEBHELPER 1 "" "Debhelper Commands" "Debhelper Commands"
.SH NAME
debhelper \- overview of the debhelper commands
.SH SYNOPSIS
.B dh_*
.I "[-v] [-a] [-i] [-s] [--no-act] [-ppackage] [-Npackage] [-Ptmpdir]"
.SH "DESCRIPTION"
Debhelper is used to help you build a debian package. The philospohy behind
debhelper is to provide a collection of small, simple, and easily
understood tools that are used in debian/rules to automate various common
aspects of building a package. This means less work for you, the packager.
It also, to some degree means that these tools can be changed if debian
policy changes, and packages that use them will require only a rebuild to
comply with the new policy.
.P
A typical debian/rules file that uses debhelper will call several debhelper
commands in sequence. Debhelper commands are all named with a "dh_" prefix.
Examples of rules files that use debhelper are in
/usr/share/doc/debhelper/examples/ .
.P
To create a new debian package using debhelper, you can just copy one of
the sample rules files and edit it by hand. Or you can try the dh-make
package, which contains a
.BR dh_make (1)
command that partially automates the process. For a more gentle
introduction, the maint-guide debian package contains a
tutorial about making your first package using debhelper.
.SH "DEBHELPER COMMANDS"
Here is the complete list of available debhelper commands. See their man
pages for additional documentation.
#LIST#
.SH "DEBHELPER CONFIG FILES"
Many debhelper commands make use of files in debian/ to control what they
do. Besides the common debian/changelog and debian/control, which are
in all packages, not just those using debhelper, some additional files can
be used to configure the behavior of specific debhelper commands. These
files are typically named debian/<package>.foo (where <package> of course,
is replaced with the package that is being acted on).
.P
For example,
dh_installdocs uses files named debian/<package>.docs to list the documentation
files it will install. See the man pages of individual commands for details
about the names and formats of the files they use.
.P
Note that if a package is the first (or only) binary package listed in
debian/control, debhelper will use debian/foo if no debian/<package>.foo
file can be found.
.P
In some rare cases, you may want to have different versions of these files
for different architectures. If files named debian/<package>.foo.<arch>
exist, where <arch> is the same as the output of "dpkg --print-architecture",
then they will be used in preference to other, more general files.
.SH "SHARED DEBHELPER OPTIONS"
The following command line options are supported by all debhelper programs.
.TP
.B \-v, \--verbose
Verbose mode: show all commands that modify the package build directory.
.TP
.B \--no-act
Do not really do anything. If used with -v, the result is that the command
will output a list of what it would have done.
.TP
.B \-a, \--arch
Act on all architecture dependent packages.
.TP
.B \-i, \--indep
Act on all architecture independent packages.
.TP
.B \-ppackage, \--package=package
Act on the package named "package".
.TP
.B \-s, \--same-arch
This is a smarter version of the -a flag, that is used in some rare
circumstances. It understands that if the control file lists "Architecture: i386"
for the package, the package should not be acted on on other architectures. So
this flag makes the command act on all "Architecture: any" packages, as well
as on any packages that have the current architecture explicitly specified.
Contrast to the -a flag, which makes the command work on all packages that
are not architecture independant.
.TP
.B \-Npackage, \--no-package=package
Do not act on the specified package even if an -a, -i, or -p option lists
the package as one that should be acted on.
.TP
.B \-Ptmpdir, \--tmpdir=tmpdir
Use "tmpdir" for package build directory. The default is debian/<package>
.SH "COMMON DEBHELPER OPTIONS"
The following command line options are supported by some debhelper programs.
See the man page of each program for a complete explanation of what the
option does.
.TP
.B \-n
Do not modify postinst/postrm/etc scripts.
.TP
.B \-Xitem, \--exclude=item
Exclude an item from processing. This option may be used multiple times,
to exclude more than one thing.
.TP
.B \-A, \-all
Makes files or other items that are specified on the command line take effect
in ALL packages acted on, not just the first.
.SH NOTES
.TP
.B Multiple binary package support
.RS
If your source package generates more than one binary package, debhelper
programs will default to acting on all binary packages when run. If your
source package happens to generate one architecture dependent package, and
another architecture independent package, this is not the correct behavior,
because you need to generate the architecture dependent packages in the
binary-arch debian/rules target, and the architecture independent packages
in the binary-indep debian/rules target.

To facilitate this, as well as give you more control over which packages
are acted on by debhelper programs, all debhelper programs accept the
.B -a
,
.B -i
,
.B -p
, and
.B -s
parameters. These parameters are cumulative. If none are given,
debhelper programs default to acting on all packages listed in the control
file.
.P
See
.BR /usr/share/doc/debhelper/examples/rules.multi
for an example of how to use this.
.RE
.TP
.B Automatic generation of debian install scripts
.RS
Some debhelper commands will automatically generate parts of debian install
scripts. If you want these automatically generated things included in your
debian install scripts, then you need to add "#DEBHELPER#" to your scripts,
in the place the code should be added. "#DEBHELPER#" will be replaced by
any auto-generated code when you run dh_installdeb.
.P
All scripts that automatically generate code in this way let it be disabled
by the -n parameter (see above).
.P
Note that the inserted code will be shell code, so you cannot directly use
it in a perl script. If you would like to embed it into a perl script, here
is one way to do that (note that I made sure that $1, $2, etc are set with
the set command):
  my $temp="set -e\\nset -- @ARGV\\n" . << 'EOF';
  #DEBHELPER#
  EOF
  system ($temp) / 256 == 0
  	or die "Problem with debhelper scripts: $!";
.RE
.TP
.B Package build directories
.RS
By default, all debhelper programs assume that the temporary directory used
for assembling the tree of files in a package is debian/<packagename>.
.P
Sometimes, you might want to use some other temporary directory. This is
supported by the
.B -P
flag. For example, "dh_installdocs -Pdebian/tmp", will use debian/tmp as the
temporary directory. Note that if you use -P, the debhelper programs can only
be acting on a single package at a time. So if you have a package that builds
many binary packages, you will need to use the -p flag to specify which
binary package the debhelper program will act on.
.RE
.TP
.B Debhelper compatability levels
.RS
From time to time, major non-backwards-compatabile changes need to be made
to debhelper, to keep it clean and well-designed as needs change and its
author gains more experience. To prevent such major changes from breaking
existing packages, the DH_COMPAT environment variable was introduced.
DH_COMPAT may be set to a number, to determine which major revision of
debhelper should be used. There are currently 3:
.TP
.B V1
Setting DH_COMPAT=1 (or leaving it unset) causes debhelper to act in
compatability mode. It will use debian/tmp as the package tree
directory for the first binary package listed in the control file, while using
debian/<package> for all other packages listed in the control file.
This mode is deprecated.
.TP
.B V2
Setting DH_COMPAT=2 causes debhelper to consitently use debian/<package>
as the package tree directory for every package that is built. This
mode is currently set by default in all the example rules files, and you
are encouraged to use it.
.TP
.B V3
Setting DH_COMPAT=3 will make debhelper start using new v3 features as
they are implemented. This will cause its behavior to change without
notice, and so may break packages that use it. See the file
"/usr/share/doc/debhelper/v3" for more information about planned
changes.
.RE
.TP
.B Doc directory symlinks
.RS
Sometimes it is useful to make a package not contain a /usr/share/doc/package
directory at all, instead placing just a dangling symlink in the binary
package, that points to some other doc directory. Policy says this is ok if
your package depends on the package whose doc directory it uses. To
accomplish this, just don't tell debhelper to install any documentation
files into the package, and use dh_link to set up the symlink (or do it by
hand), and debhelper should do the right thing: notice it is a dangling
symlink and not try to install a copyright file or changelog.
.RE
.TP
.B Other notes
.RS
In general, if any debhelper program needs a directory to exist under
debian/, it will create it. I haven't bothered to document this in all the
man pages, but for example, dh_installdeb knows to make debian/<foo>/DEBIAN/
before trying to put files there, dh_installmenu knows you need a
debian/<foo>/usr/lib/menu/ before installing the menu files, etc.
.P
Note that if you are generating a debian package that has arch-indep and
arch-dependent portions, and you are using dh_movefiles to move the
arch-indep files out of debian/tmp, you need to make sure that dh_movefiles
does this even if only the arch-dependent package is being built (for
ports to other architectures). I handle this in the example rules file
"rules.multi" by calling dh_movefiles in the install target.
.P
Once your package uses debhelper to build, be sure to add
debhelper to your Build-Depends line in debian/control.
.RE
.SH ENVIRONMENT
.TP
.I DH_VERBOSE
Enables verbose mode.
.TP
.I DH_COMPAT
Specifies what compatability level debhelper should run at. See above.
.TP
.I DH_NO_ACT
Enables no-act mode.
.TP
.I DH_OPTIONS
Anything in this variable will be prepended to the command line
arguments of all debhelper commands. This in useful in some situations,
for example, if you need to pass -p to all debhelper commands that will be
run. If you use DH_OPTIONS, be sure to use "dh_testversion 1.1.17" - older
debhelpers will ignore it and do things you don't want them to. One very
good way to set DH_OPTIONS is by using "Target-specific Variable Values" in
your debian/rules file. See the make documentation for details on doing this.
.SH "SEE ALSO"
.TP
.BR /usr/share/doc/debhelper/examples/
A set of example debian/rules files that use debhelper.
.TP
.BR http://kitenet.net/programs/debhelper/
Debhelper web site.
.SH AUTHOR
Joey Hess <joeyh@debian.org>