# dpkg-architecture

## 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
               The Debian architecture string, used in binary packages, which
               specifies the binary tree in a package repository.
    
               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.
    
               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, 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.
    
               **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/local/share/dpkg/cputable_
               Table of known CPU names and mapping to their GNU name.
               Format version 1.0 (since dpkg 1.13.2).
    
           _/usr/local/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/local/share/dpkg/tupletable_
               Mapping between Debian architecture tuples and Debian
               architecture names.  Format version 1.0 (since dpkg 1.18.11).
    
           _/usr/local/share/dpkg/abitable_
               Table of Debian architecture ABI attribute overrides.  Format
               version 2.0 (since dpkg 1.18.11).
    
       **Packaging support**
           _/usr/local/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/local/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/local/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.
    


* * *