Provided by: dpkg-dev_1.16.1.2ubuntu7_all bug

NAME

       dpkg-architecture  -  set  and  determine  the architecture for package
       building

SYNOPSIS

       dpkg-architecture [option...] [command]

DESCRIPTION

       dpkg-architecture does provide 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  -a  and  -t.  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 -a and -t 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     Print the environment variables, one each line,  in  the  format
              VARIABLE=value. This is the default action.

       -edebian-architecture
              Check   for   equality   of  architecture.  By  default  debian-
              architecture   is   compared   against   the   current    Debian
              architecture,  being  the host.  This action will not expand the
              architecture wildcards. Command finishes with an exit status  of
              0 if matched, 1 if not matched.

       -iarchitecture-wildcard
              Check  for  identity  of architecture by expanding architecture-
              wildcard as an architecture wildcard and comparing  against  the
              current  Debian  architecture.  Command  finishes  with  an exit
              status of 0 if matched, 1 if not matched.

       -qvariable-name
              Print the value of a single variable.

       -s     Print an export command. This can be used to set the environment
              variables using eval.

       -u     Print a similar command to -s but to unset all variables.

       -c command
              Execute  a command in an environment which has all variables set
              to the determined value.

       -L     Print a list of valid architecture names.

       --help Show the usage message and exit.

       --version
              Show the version and exit.

OPTIONS

       -adebian-architecture
              Set the Debian architecture.

       -tgnu-system-type
              Set the GNU system type.

       -f     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.

       Debian architecture
           The  Debian architecture string, which specifies the binary tree in
           the FTP archive. Examples: i386, sparc, hurd-i386.

       architecture wildcard
           An 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  dash:  cpu  and system. Examples: i386-linux-gnu,
           sparc-linux-gnu, i386-gnu, x86_64-netbsd.

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.

       DEB_BUILD_ARCH_CPU
           The Debian cpu name of the build machine.

       DEB_BUILD_ARCH_BITS
           The pointer size of the build machine (in bits).

       DEB_BUILD_ARCH_ENDIAN
           The endianness of the build machine (little / big).

       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.

       DEB_HOST_ARCH
           The Debian architecture of the host machine.

       DEB_HOST_ARCH_OS
           The Debian system name of the host machine.

       DEB_HOST_ARCH_CPU
           The Debian cpu name of the host machine.

       DEB_HOST_ARCH_BITS
           The pointer size of the host machine (in bits).

       DEB_HOST_ARCH_ENDIAN
           The endianness of the host machine (little / big).

       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.

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:

       Instead of:

              ARCH=`dpkg --print-architecture`
              configure $(ARCH)-linux

       please use the following:

              DEB_BUILD_GNU_TYPE := $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
              DEB_HOST_GNU_TYPE := $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)

              configure --build=$(DEB_BUILD_GNU_TYPE) --host=$(DEB_HOST_GNU_TYPE)

       Instead of:

              ARCH=`dpkg --print-architecture`
              ifeq ($(ARCH),alpha)
                ...
              endif

       please use:

              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.

       In  general,  calling  dpkg  in  the  rules  file  to  get architecture
       information  is  deprecated  (unless  you  want  to  provide   backward
       compatibility,  see below).  Especially the --print-architecture option
       is unreliable since we have Debian architectures which  don't  equal  a
       processor name.

BACKWARD COMPATIBILITY

       The  DEB_*_ARCH_BITS and DEB_*_ARCH_ENDIAN variables were introduced in
       dpkg-dev 1.15.4. Using them in  debian/rules  thus  requires  a  build-
       dependency on dpkg-dev (>= 1.15.4).

       The DEB_HOST_ARCH_CPU and DEB_HOST_ARCH_OS variables were introduced in
       dpkg-dev 1.13.2. Before this debian/rules files  tended  to  check  the
       values  of  the  DEB_HOST_GNU_CPU  or DEB_HOST_GNU_TYPE variables which
       have been subject to change.

       Where debian/rules files check these variables to decide how or what to
       compile,  this  should  be updated to use the new variables and values.
       You may wish to retain backwards compatibility with  older  version  of
       dpkg-dev by using the following code:

              DEB_HOST_ARCH_CPU := $(shell dpkg-architecture -qDEB_HOST_ARCH_CPU 2>/dev/null)
              DEB_HOST_ARCH_OS := $(shell dpkg-architecture -qDEB_HOST_ARCH_OS 2>/dev/null)

              # Take account of old dpkg-architecture output.
              ifeq ($(DEB_HOST_ARCH_CPU),)
                DEB_HOST_ARCH_CPU := $(shell dpkg-architecture -qDEB_HOST_GNU_CPU)
                ifeq ($(DEB_HOST_ARCH_CPU),x86_64)
                  DEB_HOST_ARCH_CPU := amd64
                endif
              endif
              ifeq ($(DEB_HOST_ARCH_OS),)
                DEB_HOST_ARCH_OS := $(subst -gnu,,$(shell dpkg-architecture -qDEB_HOST_GNU_SYSTEM))
                ifeq ($(DEB_HOST_ARCH_OS),gnu)
                  DEB_HOST_ARCH_OS := hurd
                endif
              endif

       And similarly for DEB_BUILD_ARCH_CPU and DEB_BUILD_ARCH_OS.

       If  you still wish to support versions of dpkg-dev that did not include
       dpkg-architecture, the following does the job:

              DEB_BUILD_ARCH := $(shell dpkg --print-architecture)
              DEB_BUILD_GNU_CPU := $(patsubst hurd-%,%,$(DEB_BUILD_ARCH))
              ifeq ($(filter-out hurd-%,$(DEB_BUILD_ARCH)),)
                DEB_BUILD_GNU_SYSTEM := gnu
              else
                DEB_BUILD_GNU_SYSTEM := linux-gnu
              endif
              DEB_BUILD_GNU_TYPE=$(DEB_BUILD_GNU_CPU)-$(DEB_BUILD_GNU_SYSTEM)

              DEB_HOST_ARCH := $(DEB_BUILD_ARCH)
              DEB_HOST_GNU_CPU := $(DEB_BUILD_GNU_CPU)
              DEB_HOST_GNU_SYSTEM := $(DEB_BUILD_GNU_SYSTEM)
              DEB_HOST_GNU_TYPE := $(DEB_BUILD_GNU_TYPE)

       Put a subset of these lines at the top of your debian/rules file; these
       default values will be overwritten if dpkg-architecture is used.

       You don't need the full set. Choose a consistent set which contains the
       values you use in the rules file. For example, if  you  only  need  the
       host  Debian  architecture, `DEB_HOST_ARCH=`dpkg --print-architecture`'
       is sufficient (this is indeed the  Debian  architecture  of  the  build
       machine, but remember that we are only trying to be backward compatible
       with native compilation).

       The -e and  -i  options  were  only  introduced  in  relatively  recent
       versions of dpkg-architecture (since dpkg 1.13.13).

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 an architecture is equal to  the  current  architecture  or  a
       given one:

              dpkg-architecture -elinux-alpha

              dpkg-architecture -amips -elinux-mips

       Check  if  the current architecture or an architecture provided with -a
       are Linux systems:

              dpkg-architecture -ilinux-any

              dpkg-architecture -ai386 -ilinux-any

FILES

       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.

SEE ALSO

       dpkg-buildpackage(1), dpkg-cross(1).

AUTHOR

       dpkg-architecture and this man page were initially  written  by  Marcus
       Brinkmann <brinkmd@debian.org>.