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 an external call to dpkg(1), and can not 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. 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 eval.
-u, --print-unset
Print a similar command to --print-unset but to unset all
variables.
-c, --command command
Execute a command 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.
-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. This is only needed when
building a cross-toolchain, one that will be built on the build
architecture, to be run on the host architecture, and to build 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 wildcard
A Debian architecture wildcard is a special architecture string
that will match any real architecture being part of it. The general
form is <kernel>-<cpu>. Examples: linux-any, any-i386, hurd-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 set by dpkg-architecture:
DEB_BUILD_ARCH
The Debian architecture of the build machine.
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 CPU part of DEB_BUILD_GNU_TYPE.
DEB_BUILD_GNU_SYSTEM
The 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_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 CPU part of DEB_HOST_GNU_TYPE.
DEB_HOST_GNU_SYSTEM
The 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_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 CPU part of DEB_TARGET_GNU_TYPE (since dpkg 1.17.14).
DEB_TARGET_GNU_SYSTEM
The 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.
/usr/share/dpkg/cputable
Table of known CPU names and mapping to their GNU name.
/usr/share/dpkg/ostable
Table of known operating system names and mapping to their GNU
name.
/usr/share/dpkg/triplettable
Mapping between Debian architecture triplets and Debian
architecture names.
/usr/share/dpkg/abitable
Table of Debian architecture ABI attribute overrides.
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.
NOTES
All long command and option names available only since dpkg 1.17.17.
SEE ALSO
dpkg-buildpackage(1), dpkg-cross(1).
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