cmake_host_system_information¶

Query various host system information.

Synopsis¶

Query host system specific information
  cmake_host_system_information(RESULT <variable> QUERY <key> ...)

Query Windows registry
  cmake_host_system_information(RESULT <variable> QUERY WINDOWS_REGISTRY <key> ...)

Query host system specific information¶

cmake_host_system_information(RESULT <variable> QUERY <key> ...)

Queries system information of the host system on which cmake runs. One or more <key> can be provided to select the information to be queried. The list of queried values is stored in <variable>.

<key> can be one of the following values:

NUMBER_OF_LOGICAL_CORES

Number of logical cores

NUMBER_OF_PHYSICAL_CORES

Number of physical cores

HOSTNAME

Hostname

FQDN

Fully qualified domain name

TOTAL_VIRTUAL_MEMORY

Total virtual memory in MiB 1

AVAILABLE_VIRTUAL_MEMORY

Available virtual memory in MiB 1

TOTAL_PHYSICAL_MEMORY

Total physical memory in MiB 1

AVAILABLE_PHYSICAL_MEMORY

Available physical memory in MiB 1

IS_64BIT

New in version 3.10.

One if processor is 64Bit

HAS_FPU

New in version 3.10.

One if processor has floating point unit

HAS_MMX

New in version 3.10.

One if processor supports MMX instructions

HAS_MMX_PLUS

New in version 3.10.

One if processor supports Ext. MMX instructions

HAS_SSE

New in version 3.10.

One if processor supports SSE instructions

HAS_SSE2

New in version 3.10.

One if processor supports SSE2 instructions

HAS_SSE_FP

New in version 3.10.

One if processor supports SSE FP instructions

HAS_SSE_MMX

New in version 3.10.

One if processor supports SSE MMX instructions

HAS_AMD_3DNOW

New in version 3.10.

One if processor supports 3DNow instructions

HAS_AMD_3DNOW_PLUS

New in version 3.10.

One if processor supports 3DNow+ instructions

HAS_IA64

New in version 3.10.

One if IA64 processor emulating x86

HAS_SERIAL_NUMBER

New in version 3.10.

One if processor has serial number

PROCESSOR_SERIAL_NUMBER

New in version 3.10.

Processor serial number

PROCESSOR_NAME

New in version 3.10.

Human readable processor name

PROCESSOR_DESCRIPTION

New in version 3.10.

Human readable full processor description

OS_NAME

New in version 3.10.

See CMAKE_HOST_SYSTEM_NAME

OS_RELEASE

New in version 3.10.

The OS sub-type e.g. on Windows Professional

OS_VERSION

New in version 3.10.

The OS build ID

OS_PLATFORM

New in version 3.10.

See CMAKE_HOST_SYSTEM_PROCESSOR

DISTRIB_INFO

New in version 3.22.

Read /etc/os-release file and define the given <variable> into a list of read variables

DISTRIB_<name>

New in version 3.22.

Get the <name> variable (see man 5 os-release) if it exists in the /etc/os-release file

Example:

cmake_host_system_information(RESULT PRETTY_NAME QUERY DISTRIB_PRETTY_NAME)
message(STATUS "${PRETTY_NAME}")

cmake_host_system_information(RESULT DISTRO QUERY DISTRIB_INFO)

foreach(VAR IN LISTS DISTRO)
  message(STATUS "${VAR}=`${${VAR}}`")
endforeach()

Output:

-- Ubuntu 20.04.2 LTS
-- DISTRO_BUG_REPORT_URL=`https://bugs.launchpad.net/ubuntu/`
-- DISTRO_HOME_URL=`https://www.ubuntu.com/`
-- DISTRO_ID=`ubuntu`
-- DISTRO_ID_LIKE=`debian`
-- DISTRO_NAME=`Ubuntu`
-- DISTRO_PRETTY_NAME=`Ubuntu 20.04.2 LTS`
-- DISTRO_PRIVACY_POLICY_URL=`https://www.ubuntu.com/legal/terms-and-policies/privacy-policy`
-- DISTRO_SUPPORT_URL=`https://help.ubuntu.com/`
-- DISTRO_UBUNTU_CODENAME=`focal`
-- DISTRO_VERSION=`20.04.2 LTS (Focal Fossa)`
-- DISTRO_VERSION_CODENAME=`focal`
-- DISTRO_VERSION_ID=`20.04`

If /etc/os-release file is not found, the command tries to gather OS identification via fallback scripts. The fallback script can use various distribution-specific files to collect OS identification data and map it into man 5 os-release variables.

Fallback Interface Variables¶

CMAKE_GET_OS_RELEASE_FALLBACK_SCRIPTS¶: In addition to the scripts shipped with CMake, a user may append full paths to his script(s) to the this list. The script filename has the following format: NNN-<name>.cmake, where NNN is three digits used to apply collected scripts in a specific order.

CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname>¶: Variables collected by the user provided fallback script ought to be assigned to CMake variables using this naming convention. Example, the ID variable from the manual becomes CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID.

CMAKE_GET_OS_RELEASE_FALLBACK_RESULT¶: The fallback script ought to store names of all assigned CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname> variables in this list.

Example:

# Try to detect some old distribution
# See also
# - http://linuxmafia.com/faq/Admin/release-files.html
#
if(NOT EXISTS "${CMAKE_SYSROOT}/etc/foobar-release")
  return()
endif()
# Get the first string only
file(
    STRINGS "${CMAKE_SYSROOT}/etc/foobar-release" CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT
    LIMIT_COUNT 1
  )
#
# Example:
#
#   Foobar distribution release 1.2.3 (server)
#
if(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT MATCHES "Foobar distribution release ([0-9\.]+) .*")
  set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME Foobar)
  set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME "${CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT}")
  set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID foobar)
  set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION ${CMAKE_MATCH_1})
  set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID ${CMAKE_MATCH_1})
  list(
      APPEND CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
      CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME
      CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME
      CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID
      CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION
      CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID
    )
endif()
unset(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT)

Footnotes

1(1,2,3,4): One MiB (mebibyte) is equal to 1024x1024 bytes.

Query Windows registry¶

New in version 3.24.

cmake_host_system_information(RESULT <variable>
                              QUERY WINDOWS_REGISTRY <key> [VALUE_NAMES|SUBKEYS|VALUE <name>]
                              [VIEW (64|32|64_32|32_64|HOST|TARGET|BOTH)]
                              [SEPARATOR <separator>]
                              [ERROR_VARIABLE <result>])

Performs query operations on local computer registry subkey. Returns a list of subkeys or value names that are located under the specified subkey in the registry or the data of the specified value name. The result of the queried entity is stored in <variable>.

Note

Querying registry for any other platforms than Windows, including CYGWIN, will always returns an empty string and sets an error message in the variable specified with sub-option ERROR_VARIABLE.

<key> specify the full path of a subkey on the local computer. The <key> must include a valid root key. Valid root keys for the local computer are:

HKLM or HKEY_LOCAL_MACHINE
HKCU or HKEY_CURRENT_USER
HKCR or HKEY_CLASSES_ROOT
HKU or HKEY_USERS
HKCC or HKEY_CURRENT_CONFIG

And, optionally, the path to a subkey under the specified root key. The path separator can be the slash or the backslash. <key> is not case sensitive. For example:

cmake_host_system_information(RESULT result QUERY WINDOWS_REGISTRY "HKLM")
cmake_host_system_information(RESULT result QUERY WINDOWS_REGISTRY "HKLM/SOFTWARE/Kitware")
cmake_host_system_information(RESULT result QUERY WINDOWS_REGISTRY "HKCU\\SOFTWARE\\Kitware")

VALUE_NAMES

Request the list of value names defined under <key>. If a default value is defined, it will be identified with the special name (default).

SUBKEYS

Request the list of subkeys defined under <key>.

VALUE <name>

Request the data stored in value named <name>. If VALUE is not specified or argument is the special name (default), the content of the default value, if any, will be returned.

# query default value for HKLM/SOFTWARE/Kitware key
cmake_host_system_information(RESULT result
                              QUERY WINDOWS_REGISTRY "HKLM/SOFTWARE/Kitware")

# query default value for HKLM/SOFTWARE/Kitware key using special value name
cmake_host_system_information(RESULT result
                              QUERY WINDOWS_REGISTRY "HKLM/SOFTWARE/Kitware"
                              VALUE "(default)")

Supported types are:

REG_SZ.
REG_EXPAND_SZ. The returned data is expanded.
REG_MULTI_SZ. The returned is expressed as a CMake list. See also SEPARATOR sub-option.
REG_DWORD.
REG_QWORD.

For all other types, an empty string is returned.

VIEW

Specify which registry views must be queried. When not specified, BOTH view is used.

64

Query the 64bit registry. On 32bit Windows, returns always an empty string.

32

Query the 32bit registry.

64_32

For VALUE sub-option or default value, query the registry using view 64, and if the request failed, query the registry using view 32. For VALUE_NAMES and SUBKEYS sub-options, query both views (64 and 32) and merge the results (sorted and duplicates removed).

32_64

For VALUE sub-option or default value, query the registry using view 32, and if the request failed, query the registry using view 64. For VALUE_NAMES and SUBKEYS sub-options, query both views (32 and 64) and merge the results (sorted and duplicates removed).

HOST

Query the registry matching the architecture of the host: 64 on 64bit Windows and 32 on 32bit Windows.

TARGET

Query the registry matching the architecture specified by CMAKE_SIZEOF_VOID_P variable. If not defined, fallback to HOST view.

BOTH

Query both views (32 and 64). The order depends of the following rules: If CMAKE_SIZEOF_VOID_P variable is defined. Use the following view depending of the content of this variable:

8: 64_32
4: 32_64

If CMAKE_SIZEOF_VOID_P variable is not defined, rely on architecture of the host:

64bit: 64_32
32bit: 32

SEPARATOR

Specify the separator character for REG_MULTI_SZ type. When not specified, the character \0 is used.

ERROR_VARIABLE <result>

Returns any error raised during query operation. In case of success, the variable holds an empty string.

cmake_host_system_information¶

Synopsis¶

Query host system specific information¶

Fallback Interface Variables¶

Query Windows registry¶

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