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 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.

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-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.

       -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 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 set by dpkg-architecture:

       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 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_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 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_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 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.   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>>.

NOTES

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

SEE ALSO

       dpkg-buildpackage(1).

1.19.0.5							    2018-04-16						      dpkg-architecture(1)