--- name: "debhelper" section: "1" platform: "linux" package: "debhelper" version: "4.0.2" release: "Debian 3.0 (Woody)" platforms: ["linux"] url: "https://new.carta.tech/debhelper" --- # debhelper(1) debhelper - the debhelper tool suite **dh\_***\** \[**-v**\] \[**-a**\] \[**-i**\] \[**-s**\] \[**--no-act**\] \[**-ppackage**\] \[**-Npackage\] \[-Ptmpdir**\] Debhelper is used to help you build a debian package. The philosophy 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. 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/* 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 dh\_make 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. Here is the complete list of available debhelper commands. See their man pages for additional documentation. build debian packages clean up package build directories compress files and fix symlinks in package build directories fix permissions of files in package build directories generate and install control file install files into package build directories install changelogs into package build directories install cron scripts into etc/cron.\* install files into the DEBIAN directory install files used by debconf in package build directories create subdirectories in package build directories install documentation into package build directories register an emacs add on package install example files into package build directories install and register info files install init scripts into package build directories install logrotate config files install man pages into package build directories old-style man page installer install debian menu files into package build directories install mime files into package build directories register modules with modutils install pam support files register a window manager install xaw wrappers config files into package build directories register X fonts create symlinks in package build directories list binary packages debhelper will act on automatically create shlibs file generate DEBIAN/md5sums file move files out of debian/tmp into subpackages calculates perl scripts & modules dependencies calculate shared library dependancies strip executables, shared libraries, and some static libraries obsolete suid registration program test directory before building debian package ensure that a package is built as root ensure that the correct version of debhelper is installed make symlinks to undocumented.7.gz man page 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). 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. 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. 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. In many cases, these config files are used to specify various types of files. Documentation or example files to install, files to move, and so on. When appropriate, in cases like these, you can use standard shell wildcard characters ('?' and '\*') in the files. The following command line options are supported by all debhelper programs. Verbose mode: show all commands that modify the package build directory. Do not really do anything. If used with -v, the result is that the command will output what it would have done. Act on all architecture dependent packages. Act on all architecture independent packages. Act on the package named "package". This option may be specified multiple times to make debhelper operate on a given set of packages. 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. 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. Use "tmpdir" for package build directory. The default is debian/\ The following command line options are supported by some debhelper programs. See the man page of each program for a complete explanation of what each option does. Do not modify postinst/postrm/etc scripts. Exclude an item from processing. This option may be used multiple times, to exclude more than one thing. Makes files or other items that are specified on the command line take effect in ALL packages acted on, not just the first.\ **Multiple binary package support** 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 **-a**, **-i**, **-p**, and **-s** parameters. These parameters are cumulative. If none are given, debhelper programs default to acting on all packages listed in the control file. See */usr/share/doc/debhelper/examples/rules.multi* for an example of how to use this in a package that generates multiple binary packages.\ **Automatic generation of debian install scripts** 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. All scripts that automatically generate code in this way let it be disabled by the -n parameter (see above). 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: $!"; ``` **Automatic generation of miscellaneous dependencies.** Some debhelper commands may make the generated package need to depend on some other packages. For example, if you use [*dh\_installdebconf*(1)](/dh_installdebconf/1.md), your package will generally need to depend on debconf. Or if you use [*dh\_installxfonts*(1)](/dh_installxfonts/1.md), your package will generally need to depend on a particular version of xutils. Keeping track of these miscellaneous dependencies can be annoying since they are dependant on how debhelper does things, so debhelper offers a way to automate it. All commands of this type, besides documenting what dependencies may be needed on their man pages, will automatically generate a substvar called ${misc:Depends}. If you put that token into your debian/control file, it will be expanded to the dependencies debhelper figures you need. This is entirely independent of the standard ${shlibs:Depends} generated by [*dh\_makeshlibs*(1)](/dh_makeshlibs/1.md), and the ${perl:Depends} generated by [*dh\_perl*(1)](/dh_perl/1.md). You can choose not to use any of these, if debhelper's guesses don't match reality.\ **Package build directories** By default, all debhelper programs assume that the temporary directory used for assembling the tree of files in a package is debian/\. Sometimes, you might want to use some other temporary directory. This is supported by the -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 also use the -p flag to specify which binary package the debhelper program will act on.\ **Debhelper compatibility levels** From time to time, major non-backwards-compatible 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 concept of debhelper compatability levels was introduced. You tell debhelper which compatability level it should use, and it modifies its behavior in various ways. You tell debhelper what compatability level to use by writing a number to debian/compat. For example, to turn on V4 mode: ``` % echo 4 > debian/compat ``` These are the available compatablity levels: This is the original debhelper compatability level, and so it is the default one. In this mode, debhelper will use debian/tmp as the package tree directory for the first binary package listed in the control file, while using debian/\ for all other packages listed in the control file. This mode is deprecated. In this mode, debhelper will consistently use debian/\ as the package tree directory for every package that is built. This mode works like V2, with the following additions: Debhelper config files support globbing via \* and ?, when appropriate. To turn this off and use those characters raw, just prefix with a backslash. dh\_makeshlibs makes the postinst and postrm scripts call ldconfig. Every file in etc/ is automatically flagged as a conffile by dh\_installdeb. This is the reccommended mode of operation. It does everything V3 does, plus: dh\_makeshlibs -V will not include the debian part of the version number in the generated dependancy line in the shlibs file. dh\_installinit uses the new invoke-rc.d program in its generated maintainer scripts. (This may later be rolled back into V3). dh\_fixperms will make all files in bin/ directories and in etc/init.d executable. dh\_link will correct existing links to conform with policy.\ **Doc directory symlinks** 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.\ **Other notes** 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/\/DEBIAN/ before trying to put files there, dh\_installmenu knows you need a debian/\/usr/lib/menu/ before installing the menu files, etc. 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. Once your package uses debhelper to build, be sure to add debhelper to your Build-Depends line in debian/control. Set to 1 to enable verbose mode. Debhelper will output every command it runs that modifies files on the build system. Temporarily specifies what compatibility level debhelper should run at, overriding any value in debian/compat. Set to 1 to enable no-act mode. Anything in this variable will be prepended to the command line arguments of all debhelper commands. This is 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 build depend on "debhelper \>= 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. A set of example debian/rules files that use debhelper. Debhelper web site. Joey Hess \