dpkg-architecture - set and determine the architecture for package
building
dpkg-architecture [option...] [command]
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 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. 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.
- -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-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.
- 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
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/.
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).
- /usr/share/dpkg/architecture.mk
- Makefile snippet that properly sets and exports all the variables that
dpkg-architecture outputs (since dpkg 1.16.1).
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
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.
- 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).
All long command and option names available only since dpkg
1.17.17.