SYNOPSIS

dpatch [options] command [command-arguments]

DESCRIPTION

dpatch is an easy to use patch system for Debian packages, somewhat similar to the dbs package, but much simpler to use.

It lets you store patches and other simple customization templates in debian/patches and otherwise does not require much reorganization of your source tree. To get the patches applied at build time you simply need to include a makefile snippet and then depend on the patch/unpatch target in the build or clean stage of debian/rules. For added flexibility, you can call /usr/bin/dpatch directly too.

GLOBAL OPTIONS

There are a few options which change the overall behaviour of dpatch, and have an effect on not only one, but most of the available commands.

These global options are:

--workdir (-d) DIRECTORY

By default, dpatch applies patches to the source tree it was run from. With this option, one can change that, and tell dpatch to work on a different tree, although taking the dpatches from the current one.

Note that this will only pass a second argument to dpatch scriptlets, and will not change to the specified directory. To do that, use the --chdir option explained below.

--chdir (-c)

When using a different working directory than the current one, change there before trying to apply patches.

This should be used together with the --workdir option.

--strict (-S)

Enable strict mode, which means that dpatch will bail out early even on warnings (like when trying to apply a patch which is already applied - normally it will simply skip it).

--force (-F)

Force the application or deapplication of patches, even if dpatch would normally skip them because the operation was already done earlier.

--with-cpp

Force the use of cpp. Overrides use of DPATCH_OPTION_CPP=1 option in debian/patches/00options file.

COMMANDS

Patch handling commands

There is a generic syntax for all patch handling commands, namely that, that the command itself takes a list of dpatch names to work with, then does what it is meant to do on all of them, in the exact same order it was specified on the command line.

Then, there is a version of each patch handling command with an -all suffix, which does not take any arguments, and performs the necessary action for each and every available dpatch.

The last variation is a command with a -until or -up-to suffix, which takes only one argument: the name of a dpatch. The appropriate action will be performed on all dpatches up to and including this specified one.

apply [options]
patch [options]

Applies one or more dpatches to the working tree (the current directory, if not told otherwise). By default the specified patches will be applied in the exact same order they were specified.

Options

--stampdir=directory, -s=directory

Put stamp files into directory instead of the default debian/patched.

--help (-h)

Print a short help message about the command.

--quiet (-q)

Forces the command to not print anything.

--verbose (-v)

Disables hiding of the scriptlet output.

deapply [options]
unpatch [options]

Deapplies one or more dpatches to the working tree (the current directory, if not told otherwise). By default the specified patches will be deapplied in the reverse order they were specified as one generally should deapply in reverse order (compared to the apply order, that is).

Options

--stampdir=directory, -s=directory

Use stamp files in directory instead of the default debian/patched.

--help (-h)

Print a short help message about the command.

--quiet (-q)

Forces the command to not print anything.

--verbose (-v)

Disables hiding of the scriptlet output.

cat [options]

Print meta-information about a dpatch, such as its name, author and description (any of which can be disabled with the appropriate option).

Options

--no-meta, --desc-only (-nm, -d)

Only print the patch description.

--author-only (-a)

Only print the author of the patch.

--no-desc, (-nd)

Do not print the patch description.

--help (-h)

Print a short help message about the command.

--quiet (-q)

Forces the command to not print anything.

list [options]

List the name of the given patches. This commands is not really useful, except the list-all variant, which lists all available patches.

Options

--help (-h)

Print a short help message about the command.

status [options]

Prints the status of the given patches - whether they are applied to the working tree or not.

Options

--stampdir=directory, -s=directory

Use stamp files in directory instead of the default debian/patched.

--help (-h)

Print a short help message about the command.

--quiet (-q)

Forces the command to not print anything.

log [options]

Displays the log of the given patching attempts.

Options

--stampdir=directory, -s=directory

Use stamp files in directory instead of the default debian/patched.

--help (-h)

Print a short help message about the command.

--quiet (-q)

Forces the command to not print anything, but the logs without extra sugar on top.

call [options]

Call a dpatch with a user-specified argument. All arguments with a pkg- prefix is guaranteed to be unused by dpatch itself, and are reserved for use with this very command.

This command is most useful for extracting custom meta-information from dpatch scriptlets.

Options

--argument=arg (-a=arg)

Call patches with arg as argument.

--help (-h)

Print a short help message about the command.

--quiet (-q)

Forces the command to not print anything.

Miscellaneous commands

patch-template [options] [patchname] [description]

Print a quasi-standard dpatch script template, based on the information give on the command-line. If a description given, it will be folded at about 72 characters into multiple lines appropriately.

When prepending the template to STDIN, the contents of the standard input will be printed right after the template.

Options

--prepend (-p)

Prepend the template to STDIN.

--help (-h)

Print a short help message about the command.

help (--help, -h) [command]

Attempt to give a little more detailed help about dpatch itself, or about a given dpatch command.

version

Prints the dpatch version number and exits.

DPATCH IN DEBIAN PACKAGES

There are two different ways to use dpatch in debian/rules: calling it directly, or including dpatch.make(7). Only the former method will be described here - the latter has its own manual page.

NOTE: The following examples also require adding the .NOTPARALLEL flag to the head of debian/rules since the dependency lists rely on the order of the execution. Without .NOTPARALLEL, they execution order may be wrong with multiple make threads (the -j option).

In most situations, one will want to run dpatch as soon during the build process, as possible. How that can be accomplished depends heavily on the existing debian/rules. However, in common practice most packages have a build (or build-stamp), config.status, or configure (or configure-stamp) target. The easiest way to make dpatching the very first thing, one only has to write a rule that calls dpatch, and add it to the list of prerequisites for the appropriate target (see above).

Deapplying dpatches can be easy or a bit more tricky. If nothing in the clean rule touches files modified by dpatches (creating incompatible changes), you can safely add unpatch to the list of the clean rules dependencies.

If the patches might affect the build system, they should be deapplied after the source tree has been cleaned. To do this, rename the clean target to, say, clean-patched, write a rule that calls dpatch to deapply the dpatches, and make a new clean rule that has clean-patched and unpatch as its prerequisites.

Let us look at an example! First, let us look at the relevant parts of the original debian/rules of our imaginary package:

config.status: configure
        ./configure --prefix=/usr --mandir=/usr/share
build: config.status
        ${MAKE}
clean:
        $(testdir)
        $(testroot)
        ${MAKE} distclean
        rm -rf debian/imaginary-package debian/files debian/substvars

After dpatchifying, this would look like this:

config.status: patch configure
        ./configure --prefix=/usr --mandir=/usr/share
build: config.status
        ${MAKE}
clean: clean-patched unpatch
clean-patched:
        $(testdir)
        $(testroot)
        ${MAKE} distclean
        rm -rf debian/imaginary-package debian/files debian/substvars
patch: patch-stamp
patch-stamp:
        dpatch apply-all
        dpatch cat-all >patch-stamp
unpatch:
        dpatch deapply-all
        rm -rf patch-stamp debian/patched

Adding dpatch scriptlets to a package

When using dpatch, one surely wants to tell the system what dpatches to apply, and which ones to discard. In the most common situation, one only needs to list the names of the dpatches (the filenames relative to debian/patches) in debian/patches/00list. They usually have the extension .dpatch and the extension can be omitted, thus a file debian/patches/01_one_patch.dpatch is written as 01_one_patch inside debian/patches/00list

However, there may be situations where something more flexible is needed, like applying the same patch on only two architectures, say, m68k and powerpc. One solve this in at least two very different ways: One is to list the same patch in both debian/patches/00list.m68k and debian/patches/00list.powerpc, the other is to use DPATCH_OPTION_CPP=1 in debian/patches/00options. 00list file is passed through cpp command with DEB_BUILD_ARCH variable set to the architecture, and DEB_BUILD_ARCH_architecture being set to 1. With cpp, our sample debian/patches/00list might look like this:

01_manpage_typo
#if defined(DEB_BUILD_ARCH_m68k) || defined(DEB_BUILD_ARCH_powerpc)
/* This patch fixes a random build-time breakage on Macintosh boxen. */
02_macintosh_foo
#endif

Creating dpatch scriptlets

There are many ways to create dpatch scriptlets. They are simple, executable files, which follow a standardised calling convention (documented in dpatch(7)).

You can fire up your $EDITOR, or use dpatch-edit-patch, and you should be all set.

For most cases, where the dpatch file is only to apply a simple patch, there is an even easier way:

dpatch patch-template -p "01_some_patch" "A random patch" \
        <random.diff >debian/patches/01_some_patch.dpatch

FILES

debian/patches/00list

The list of patches to apply, deapply, or otherwise fiddle with.

debian/patches/00list.arch

List of patches to work with - additionally to the common list in debian/patches/00list -, when building on the arch architecture.

/etc/dpatch.conf

System-wide configuration file for dpatch, for setting global options permanently.

~/.dpatch.conf

Per-user configuration file, for setting global options permanently.

AUTHORS

dpatch was written by Joerg Jaspert, David B Harris, Gergely Nagy, Junichi Uekawa and others.

This manual page was written by Gergely Nagy, and updated by Junichi Uekawa