platform

Name

platform — System identification support code and utilities

Synopsis

package require platform ?1.0.10?
platform::generic
platform::identify
platform::patterns identifier

Description

The platform package provides several utility commands useful for the identification of the architecture of a machine running Tcl.

Whilst Tcl provides the tcl_platform array for identifying the current architecture (in particular, the platform and machine elements) this is not always sufficient. This is because (on Unix machines) tcl_platform reflects the values returned by the uname command and these are not standardized across platforms and architectures. In addition, on at least one platform (AIX) the tcl_platform(machine) contains the CPU serial number.

Consequently, individual applications need to manipulate the values in tcl_platform (along with the output of system specific utilities) - which is both inconvenient for developers, and introduces the potential for inconsistencies in identifying architectures and in naming conventions.

The platform package prevents such fragmentation - i.e., it establishes a standard naming convention for architectures running Tcl and makes it more convenient for developers to identify the current architecture a Tcl program is running on.

Commands

platform::identify

This command returns an identifier describing the platform the Tcl core is running on. The returned identifier has the general format OS-CPU. The OS part of the identifier may contain details like kernel version, libc version, etc., and this information may contain dashes as well. The CPU part will not contain dashes, making the preceding dash the last dash in the result.

platform::generic

This command returns a simplified identifier describing the platform the Tcl core is running on. In contrast to platform::identify it leaves out details like kernel version, libc version, etc. The returned identifier has the general format OS-CPU.

platform::patterns identifier

This command takes an identifier as returned by platform::identify and returns a list of identifiers describing compatible architectures.

Example

This can be used to allow an application to be shipped with multiple builds of a shared library, so that the same package works on many versions of an operating system. For example:

package require platform
# Assume that app script is .../theapp/bin/theapp.tcl
set binDir [file dirname [file normalize [info script]]]
set libDir [file join $binDir .. lib]
set platLibDir [file join $libDir [platform::identify]]
load [file join $platLibDir support[info sharedlibextension]]