dpkg-architecture(1) dpkg suite dpkg-architecture(1)

NAME
dpkg-architecture - set and determine the architecture for package building

SYNOPSIS
dpkg-architecture [option...] [command]

DESCRIPTION
dpkg-architecture provides a facility to determine and set the build and host architecture for package building.

The build architecture is always determined by either the DEB_BUILD_ARCH variable if set (and --force not being specified)
or by an external call to dpkg(1), and cannot be set at the command line.

You can specify the host architecture by providing one or both of the options --host-arch and --host-type, otherwise the
DEB_HOST_ARCH variable is used if set (and --force not being specified). The default is determined by an external call to
gcc(1), or the same as the build architecture if CC or gcc are both not available. One out of --host-arch and --host-type is
sufficient, the value of the other will be set to a usable default. Indeed, it is often better to only specify one, because
dpkg-architecture will warn you if your choice does not match the default.

COMMANDS
-l, --list
Print the environment variables, one each line, in the format VARIABLE=value. This is the default action.

-e, --equal architecture
Check for equality of architecture (since dpkg 1.13.13). It compares the current or specified Debian host architecture
against architecture, to check if they are equal. This action will not expand the architecture wildcards. Command
finishes with an exit status of 0 if matched, 1 if not matched.

-i, --is architecture-wildcard
Check for identity of architecture (since dpkg 1.13.13). It compares the current or specified Debian host architecture
against architecture-wildcard after having expanded it as an architecture wildcard, to check if they match. Command
finishes with an exit status of 0 if matched, 1 if not matched.

-q, --query variable-name
Print the value of a single variable.

-s, --print-set
Print an export command. This can be used to set the environment variables using the POSIX shell or make eval, depending
on the output format.

-u, --print-unset
Print a similar command to --print-set but to unset all variables.

-c, --command command-string
Execute a command-string in an environment which has all variables set to the determined value.

-L, --list-known
Print a list of valid architecture names. Possibly restricted by one or more of the matching options --match-wildcard,
--match-bits or --match-endian (since dpkg 1.17.14).

-?, --help
Show the usage message and exit.

--version
Show the version and exit.

OPTIONS
-a, --host-arch architecture
Set the host Debian architecture.

-t, --host-type gnu-system-type
Set the host GNU system type.

-A, --target-arch architecture
Set the target Debian architecture (since dpkg 1.17.14).

-T, --target-type gnu-system-type
Set the target GNU system type (since dpkg 1.17.14).

-W, --match-wildcard architecture-wildcard
Restrict the architectures listed by --list-known to ones matching the specified architecture wildcard (since dpkg
1.17.14).

-B, --match-bits architecture-bits
Restrict the architectures listed by --list-known to ones with the specified CPU bits (since dpkg 1.17.14). Either 32 or
64.

-E, --match-endian architecture-endianness
Restrict the architectures listed by --list-known to ones with the specified endianness (since dpkg 1.17.14). Either
little or big.

--print-format format
Sets the output format for --print-set and --print-unset (since dpkg 1.20.6), to either shell (default) or make.

-f, --force
Values set by existing environment variables with the same name as used by the scripts are honored (i.e. used by dpkg-
architecture), except if this force flag is present. This allows the user to override a value even when the call to
dpkg-architecture is buried in some other script (for example dpkg-buildpackage(1)).

TERMS
build machine
The machine the package is built on.

host machine
The machine the package is built for.

target machine
The machine the compiler is building for, or the emulator will run code for. This is only needed when building a cross-
toolchain (or emulator), one that will be built on the build architecture, to be run on the host architecture, and to
build (or run emulated) code for the target architecture.

Debian architecture
The Debian architecture string, which specifies the binary tree in the FTP archive. Examples: i386, sparc, hurd-i386.

Debian architecture tuple
A Debian architecture tuple is the fully qualified architecture with all its components spelled out. This differs with
Debian architectures in that at least the cpu component does not embed the abi. The current tuple has the form
abi-libc-os-cpu. Examples: base-gnu-linux-amd64, eabihf-musl-linux-arm.

Debian architecture wildcard
A Debian architecture wildcard is a special architecture string that will match any real architecture being part of it.
The general form is a Debian architecture tuple with four or less elements, and with at least one of them being any.
Missing elements of the tuple are prefixed implicitly as any, and thus the following pairs are equivalent:

any-any-any-any = any
any-any-os-any = os-any
any-libc-any-any = libc-any-any

Examples: linux-any, any-i386, hurd-any, eabi-any-any-arm, musl-any-any.

GNU system type
An architecture specification string consisting of two parts separated by a hyphen: cpu and system. Examples:
i586-linux-gnu, sparc-linux-gnu, i686-gnu, x86_64-netbsd.

multiarch triplet
The clarified GNU system type, used for filesystem paths. This triplet does not change even when the baseline ISA gets
bumped, so that the resulting paths are stable over time. The only current difference with the GNU system type is that
the CPU part for i386 based systems is always i386. Examples: i386-linux-gnu, x86_64-linux-gnu. Example paths:
/lib/powerpc64le-linux-gnu/, /usr/lib/i386-kfreebsd-gnu/.

VARIABLES
The following variables are read from the environment (unless --force has been specified) and set by dpkg-architecture (see
the TERMS section for a description of the naming scheme):

DEB_BUILD_ARCH
The Debian architecture of the build machine.

DEB_BUILD_ARCH_ABI
The Debian ABI name of the build machine (since dpkg 1.18.11).

DEB_BUILD_ARCH_LIBC
The Debian libc name of the build machine (since dpkg 1.18.11).

DEB_BUILD_ARCH_OS
The Debian system name of the build machine (since dpkg 1.13.2).

DEB_BUILD_ARCH_CPU
The Debian CPU name of the build machine (since dpkg 1.13.2).

DEB_BUILD_ARCH_BITS
The pointer size of the build machine (in bits; since dpkg 1.15.4).

DEB_BUILD_ARCH_ENDIAN
The endianness of the build machine (little / big; since dpkg 1.15.4).

DEB_BUILD_GNU_CPU
The GNU CPU part of DEB_BUILD_GNU_TYPE.

DEB_BUILD_GNU_SYSTEM
The GNU system part of DEB_BUILD_GNU_TYPE.

DEB_BUILD_GNU_TYPE
The GNU system type of the build machine.

DEB_BUILD_MULTIARCH
The clarified GNU system type of the build machine, used for filesystem paths (since dpkg 1.16.0).

DEB_HOST_ARCH
The Debian architecture of the host machine.

DEB_HOST_ARCH_ABI
The Debian ABI name of the host machine (since dpkg 1.18.11).

DEB_HOST_ARCH_LIBC
The Debian libc name of the host machine (since dpkg 1.18.11).

DEB_HOST_ARCH_OS
The Debian system name of the host machine (since dpkg 1.13.2).

DEB_HOST_ARCH_CPU
The Debian CPU name of the host machine (since dpkg 1.13.2).

DEB_HOST_ARCH_BITS
The pointer size of the host machine (in bits; since dpkg 1.15.4).

DEB_HOST_ARCH_ENDIAN
The endianness of the host machine (little / big; since dpkg 1.15.4).

DEB_HOST_GNU_CPU
The GNU CPU part of DEB_HOST_GNU_TYPE.

DEB_HOST_GNU_SYSTEM
The GNU system part of DEB_HOST_GNU_TYPE.

DEB_HOST_GNU_TYPE
The GNU system type of the host machine.

DEB_HOST_MULTIARCH
The clarified GNU system type of the host machine, used for filesystem paths (since dpkg 1.16.0).

DEB_TARGET_ARCH
The Debian architecture of the target machine (since dpkg 1.17.14).

DEB_TARGET_ARCH_ABI
The Debian ABI name of the target machine (since dpkg 1.18.11).

DEB_TARGET_ARCH_LIBC
The Debian libc name of the target machine (since dpkg 1.18.11).

DEB_TARGET_ARCH_OS
The Debian system name of the target machine (since dpkg 1.17.14).

DEB_TARGET_ARCH_CPU
The Debian CPU name of the target machine (since dpkg 1.17.14).

DEB_TARGET_ARCH_BITS
The pointer size of the target machine (in bits; since dpkg 1.17.14).

DEB_TARGET_ARCH_ENDIAN
The endianness of the target machine (little / big; since dpkg 1.17.14).

DEB_TARGET_GNU_CPU
The GNU CPU part of DEB_TARGET_GNU_TYPE (since dpkg 1.17.14).

DEB_TARGET_GNU_SYSTEM
The GNU system part of DEB_TARGET_GNU_TYPE (since dpkg 1.17.14).

DEB_TARGET_GNU_TYPE
The GNU system type of the target machine (since dpkg 1.17.14).

DEB_TARGET_MULTIARCH
The clarified GNU system type of the target machine, used for filesystem paths (since dpkg 1.17.14).

FILES
Architecture tables
All these files have to be present for dpkg-architecture to work. Their location can be overridden at runtime with the
environment variable DPKG_DATADIR. These tables contain a format Version pseudo-field on their first line to mark their
format, so that parsers can check if they understand it, such as "# Version=1.0".

/usr/share/dpkg/cputable
Table of known CPU names and mapping to their GNU name. Format version 1.0 (since dpkg 1.13.2).

/usr/share/dpkg/ostable
Table of known operating system names and mapping to their GNU name. Format version 2.0 (since dpkg 1.18.11).

/usr/share/dpkg/tupletable
Mapping between Debian architecture tuples and Debian architecture names. Format version 1.0 (since dpkg 1.18.11).

/usr/share/dpkg/abitable
Table of Debian architecture ABI attribute overrides. Format version 2.0 (since dpkg 1.18.11).

Packaging support
/usr/share/dpkg/architecture.mk
Makefile snippet that properly sets and exports all the variables that dpkg-architecture outputs (since dpkg 1.16.1).

EXAMPLES
dpkg-buildpackage accepts the -a option and passes it to dpkg-architecture. Other examples:

CC=i386-gnu-gcc dpkg-architecture -c debian/rules build

eval $(dpkg-architecture -u)

Check if the current or specified host architecture is equal to an architecture:

dpkg-architecture -elinux-alpha

dpkg-architecture -amips -elinux-mips

Check if the current or specified host architecture is a Linux system:

dpkg-architecture -ilinux-any

dpkg-architecture -ai386 -ilinux-any

Usage in debian/rules
The environment variables set by dpkg-architecture are passed to debian/rules as make variables (see make documentation).
However, you should not rely on them, as this breaks manual invocation of the script. Instead, you should always initialize
them using dpkg-architecture with the -q option. Here are some examples, which also show how you can improve the cross
compilation support in your package:

Retrieving the GNU system type and forwarding it to ./configure:

DEB_BUILD_GNU_TYPE ?= $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
DEB_HOST_GNU_TYPE ?= $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
[...]
ifeq ($(DEB_BUILD_GNU_TYPE), $(DEB_HOST_GNU_TYPE))
confflags += --build=$(DEB_HOST_GNU_TYPE)
else
confflags += --build=$(DEB_BUILD_GNU_TYPE) \
--host=$(DEB_HOST_GNU_TYPE)
endif
[...]
./configure $(confflags)

Doing something only for a specific architecture:

DEB_HOST_ARCH ?= $(shell dpkg-architecture -qDEB_HOST_ARCH)

ifeq ($(DEB_HOST_ARCH),alpha)
[...]
endif

or if you only need to check the CPU or OS type, use the DEB_HOST_ARCH_CPU or DEB_HOST_ARCH_OS variables.

Note that you can also rely on an external Makefile snippet to properly set all the variables that dpkg-architecture can
provide:

include /usr/share/dpkg/architecture.mk

ifeq ($(DEB_HOST_ARCH),alpha)
[...]
endif

In any case, you should never use dpkg --print-architecture to get architecture information during a package build.

ENVIRONMENT
DPKG_DATADIR
If set, it will be used as the dpkg data directory, where the architecture tables are located (since dpkg 1.14.17).
Defaults to «/usr/share/dpkg».

DPKG_COLORS
Sets the color mode (since dpkg 1.18.5). The currently accepted values are: auto (default), always and never.

DPKG_NLS
If set, it will be used to decide whether to activate Native Language Support, also known as internationalization (or
i18n) support (since dpkg 1.19.0). The accepted values are: 0 and 1 (default).

NOTES
All long command and option names available only since dpkg 1.17.17.