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Manual: dpkg-architecture

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.

If the command-string contains shell metacharacters, then it will be invoked through the system bourne shell.

-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 that itself will build (or run emulated) code for the target architecture.

Debian architecture
A Debian architecture describes a “machine” (considering it as an abstraction not necessarily tied to an actual
physical device) representing a specific execution environment, including its CPU and attributes (such as
endianness and bits), an operating system (usually a kernel, but other paradigms using userland services are
possible) and its interfaces towards userland including the executable format and their ABI, and a libc library
and its ABI.

The special architecture all denotes an architecture independent execution environment, used for things such as
shell and Perl scripts or documentation.

A Debian architecture is used in binary package metadata and filenames (which specifies the binary tree in a
package repository), and can appear in package relationships.

An architecture must start with an alphanumeric character (“0-9a-zA-Z”), and then gets followed by alphanumeric
or dash (“-”) characters.

Examples: amd64, i386, sparc64, hurd-amd64, musl-linux-riscv64.

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 that acts as a pattern and will match any ”machine”
architecture being part of it (except for all).

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
A GNU architecture specification string consisting of two parts separated by a hyphen: CPU and system.

The CPU part never contains a hyphen, while the system part might itself contain a hyphen to separate a kernel
from its general ABI, where the general ABI might contain both runtime (such as libc) and executable ABI
specifiers joined without a hyphen.

Examples: i586-linux-gnu, sparc64-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-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.

Note: If you are not building tools that need to run during the build, these are probably not the variables you
are looking for. Please see "TERMS" section for the meanings of these terms.

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).

Note: If you are not building cross-toolchains (or emulators), these are probably not the variables you are
looking for. Please see "TERMS" section for the meanings of these terms.

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-arm64

dpkg-architecture -ariscv64 -elinux-riscv64

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

dpkg-architecture -ilinux-any

dpkg-architecture -aamd64 -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),arm64)
[...]
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),arm64)
[...]
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.

Manual: dpkg-architecture

Related Commands: