practcl(n) 0.16.4 practcl "The The Proper Rational API for C to Tool Command Language Module"


practcl - The Practcl Module

Table Of Contents


  • package require TclOO 1.0


The Practcl module is a tool for integrating large modules for C API Tcl code that requires custom Tcl types and TclOO objects.

The concept with Practcl is that is a single file package that can assist any tcl based project with distribution, compilation, linking, VFS preparation, executable assembly, and installation. Practcl also allows one project to invoke the build system from another project, allowing complex projects such as a statically linked basekit to be assembled with relative ease.

Practcl ships as a single file, and aside from a Tcl 8.6 interpreter, has no external dependencies.

Making a practcl project


proc practcl::cat fname

Concatenate a file

proc practcl::docstrip text

Strip the global comments from tcl code. Used to prevent the documentation markup comments from clogging up files intended for distribution in machine readable format.

proc putb ?map? text

Append a line of text to a variable. Optionally apply a string mapping.

proc Proc name arglist body

Generate a proc if no command already exists by that name

proc noop ?args?

A command to do nothing. A handy way of negating an instruction without having to comment it completely out. It's also a handy attachment point for an object to be named later

proc practcl::debug ?args?
proc practcl::doexec ?args?

Drop in a static copy of Tcl

proc practcl::doexec_in path ?args?
proc practcl::dotclexec ?args?
proc practcl::domake path ?args?
proc practcl::domake.tcl path ?args?
proc practcl::fossil path ?args?
proc practcl::fossil_status dir
proc practcl::os
proc practcl::mkzip exename barekit vfspath

Build a zipfile. On tcl8.6 this invokes the native Zip implementation on older interpreters this invokes zip via exec

proc practcl::sort_dict list

Dictionary sort a key/value list. Needed because pre tcl8.6 does not have lsort -stride 2

proc practcl::local_os

Returns a dictionary describing the local operating system. Fields return include:

  • download - Filesystem path where fossil repositories and source tarballs are downloaded for the current user

  • EXEEXT - The extension to give to executables. (i.e. .exe on windows)

  • fossil_mirror - A URI for a local network web server who acts as a fossil repository mirror

  • local_install - Filesystem path where packages for local consumption by the current user are installed

  • prefix - The prefix as given to the Tcl core/TEA for installation to local_install in ./configure

  • sandbox - The file location where this project unpacks external projects

  • TEACUP_PROFILE - The ActiveState/Teacup canonical name for this platform (i.e. win32-ix86 macosx10.5-i386-x86_84)

  • TEACUP_OS - The local operating system (windows, macosx, openbsd, etc). Gives the same answer as tcl.m4, except that macosx is given as macosx instead of Darwin.

  • TEA_PLATFORM - The platform returned by uname -s-uname -r (on Unix), or "windows" on Windows

  • TEACUP_ARCH - The processor architecture for the local os (i.e. ix86, x86_64)

  • TEACUP_ARCH - The processor architecture for the local os (i.e. ix86, x86_64)

  • teapot - Filesystem path where teapot package files are downloaded for the current user

  • userhome - File path to store localized preferences, cache download files, etc for the current user

This command uses a combination of local checks with Exec, any file that is resident, autoconf data where already computed, and data gleaned from a file named practcl.rc in userhome. The location for userhome varies by platform and operating system:

  • Windows: ::env(LOCALAPPDATA)/Tcl

  • Macos: ~/Library/Application Support/Tcl

  • Other: ~/tcl

proc practcl::config.tcl path

A transparent call to ::practcl::read_configuration to preserve backward compadibility with older copies of Practcl

proc practcl::read_configuration path

Detect local platform. This command looks for data gleaned by autoconf or autosetup in the path specified, or perform its own logic tests if neither has been run. A file named present in the location indicates that this project is cross compiling, and the data stored in that file is used for the compiler and linker.

This command looks for information from the following files, in the following order:

  • config.tcl - A file generated by autoconf/configure in newer editions of TEA, encoded as a Tcl script.

  • - A file containing cross compiler information, encoded as a SH script

  • ::env(VisualStudioVersion) - On Windows, and environmental value that indicates MS Visual Studio is installed

This command returns a dictionary containing all of the data cleaned from the sources above. In the absence of any guidance this command returns the same output as ::practcl::local_os. In this mode, if the environmental variable VisualStudioVersion exists, this command will provide a template of fields that are appropriate for compiling on Windows under Microsoft Visual Studio. The USEMSVC flag in the dictionary is a boolean flag to indicate if this is indeed the case.

proc practcl::tcllib_require pkg ?args?

Try to load a package, and failing that retrieve tcllib

proc practcl::platform::tcl_core_options os

Return the string to pass to ./configure to compile the Tcl core for the given OS.

  • windows: --with-tzdata --with-encoding utf-8

  • macosx: --enable-corefoundation=yes --enable-framework=no --with-tzdata --with-encoding utf-8

  • other: --with-tzdata --with-encoding utf-8

proc practcl::platform::tk_core_options os
proc practcl::read_rc_file filename ?localdat ?

Read a stylized key/value list stored in a file

proc practcl::read_sh_subst line info

Converts a file into a series of Tcl variables

proc practcl::read_sh_file filename ?localdat ?
proc filename

A simpler form of read_sh_file tailored to pulling data from (tcl|tk)

proc practcl::read_Makefile filename

A simpler form of read_sh_file tailored to pulling data from a Makefile

proc practcl::cputs varname ?args?

Append arguments to a buffer The command works like puts in that each call will also insert a line feed. Unlike puts, blank links in the interstitial are suppressed

proc practcl::tcl_to_c body
proc practcl::_tagblock text ?style tcl? ?note ?
proc practcl::de_shell data
proc practcl::grep pattern ?files ?

Search for the pattern pattern amongst $files

proc practcl::file_lexnormalize sp
proc practcl::file_relative base dst

Calculate a relative path between base and dst


  ::practcl::file_relative ~/build/tcl/unix ~/build/tcl/library
  > ../library
proc practcl::findByPattern basedir patterns
proc practcl::log fname comment

Record an event in the practcl log

proc practcl::_pkgindex_simpleIndex path
proc practcl::_pkgindex_directory path

Return true if the pkgindex file contains any statement other than "package ifneeded" and/or if any package ifneeded loads a DLL

proc practcl::_pkgindex_path_subdir path

Helper function for ::practcl::pkgindex_path

proc practcl::pkgindex_path ?args?

Index all paths given as though they will end up in the same virtual file system

proc practcl::installDir d1 d2

Delete the contents of d2, and then recusively Ccopy the contents of d1 to d2.

proc practcl::copyDir d1 d2 ?toplevel 1?

Recursively copy the contents of d1 to d2

proc practcl::buildModule modpath
proc practcl::installModule modpath DEST

Install a module from MODPATH to the directory specified. dpath is assumed to be the fully qualified path where module is to be placed. Any existing files will be deleted at that path. If the path is symlink the process will return with no error and no action. If the module has contents in the build/ directory that are newer than the .tcl files in the module source directory, and a build/build.tcl file exists, the build/build.tcl file is run. If the source directory includes a file named index.tcl, the directory is assumed to be in the tao style of modules, and the entire directory (and all subdirectories) are copied verbatim. If no index.tcl file is present, all .tcl files are copied from the module source directory, and a pkgIndex.tcl file is generated if non yet exists. I a folder named htdocs exists in the source directory, that directory is copied verbatim to the destination.

proc practcl::trigger ?args?

Trigger build targets, and recompute dependencies


  ::practcl::LOCAL make trigger {*}$args
  foreach {name obj} [::practcl::LOCAL make objects] {
    set ::make($name) [$obj do]
proc practcl::depends ?args?

Calculate if a dependency for any of the arguments needs to be fulfilled or rebuilt.


  ::practcl::LOCAL make depends {*}$args
proc practcl::target name info ?action ?

Declare a build product. This proc is just a shorthand for ::practcl::LOCAL make task $name $info $action

Registering a build product with this command will create an entry in the global array, and populate a value in the global array.


  set obj [::practcl::LOCAL make task $name $info $action]
  set ::make($name) 0
  set filename [$obj define get filename]
  if {$filename ne {}} {
    set ::target($name) $filename


Class practcl::doctool

{ set authors {
   {John Doe} {}
   {Tom RichardHarry} {}
 # Create the object
 ::practcl::doctool create AutoDoc
 set fout [open [file join $moddir module.tcl] w]
 foreach file [glob [file join $srcdir *.tcl]] {
   set content [::practcl::cat [file join $srcdir $file]]
    # Scan the file
    AutoDoc scan_text $content
    # Strip the comments from the distribution
    puts $fout [::practcl::docstrip $content]
 # Write out the manual page
 set manout [open [file join $moddir] w]
 dict set args header [string map $modmap [::practcl::cat [file join $srcdir manual.txt]]]
 dict set args footer [string map $modmap [::practcl::cat [file join $srcdir footer.txt]]]
 dict set args authors $authors
 puts $manout [AutoDoc manpage {*}$args]
 close $manout

Tool for build scripts to dynamically generate manual files from comments in source code files


method constructor
method argspec ?args?

Process an argument list into an informational dict. This method also understands non-positional arguments expressed in the notation of Tip 471

The output will be a dictionary of all of the fields and whether the fields are positional, mandatory, and whether they have a default value.


   my argspec {a b {c 10}}
   > a {positional 1 mandatory 1} b {positional 1 mandatory 1} c {positional 1 mandatory 0 default 10}
method comment block

Convert a block of comments into an informational dictionary. If lines in the comment start with a single word ending in a colon, all subsequent lines are appended to a dictionary field of that name. If no fields are given, all of the text is appended to the description field.


 my comment {Does something cool}
 > description {Does something cool}
 my comment {
 title : Something really cool
 author : Sean Woods
 author : John Doe
 description :
 This does something really cool!
 > description {This does something really cool!}
   title {Something really cool}
   author {Sean Woods
   John Doe}
method keyword.Annotation resultvar commentblock type name body
method keyword.Class resultvar commentblock name body

Process an oo::objdefine call that modifies the class object itself

method keyword.class resultvar commentblock name body

Process an oo::define, clay::define, etc statement.

method keyword.Class_Method resultvar commentblock name ?args?

Process a statement for a clay style class method

method keyword.method resultvar commentblock name ?args?

Process a statement for a tcloo style object method

method keyword.proc commentblock name ?args?

Process a proc statement

method reset

Reset the state of the object and its embedded coroutine

method Main

Main body of the embedded coroutine for the object

method section.method keyword method minfo

Generate the manual page text for a method or proc

method section.annotation type name iinfo
method section.class class_name class_info

Generate the manual page text for a class

method section.command procinfo

Generate the manual page text for the commands section

method manpage ?header value? ?footer value? ?authors list?

Generate the manual page. Returns the completed text suitable for saving in .man file. The header argument is a block of doctools text to go in before the machine generated section. footer is a block of doctools text to go in after the machine generated section. authors is a list of individual authors and emails in the form of AUTHOR EMAIL ?AUTHOR EMAIL?...

method scan_text text

Scan a block of text

method scan_file filename

Scan a file of text

Class practcl::toolset

Ancestor-less class intended to be a mixin which defines a family of build related behaviors that are modified when targetting either gcc or msvc

Class Methods

classmethod select object

Perform the selection for the toolset mixin



find or fake a key/value list describing this project

method BuildDir PWD

Compute the location where the product will be built

method MakeDir srcdir

Return where the Makefile is located relative to srcdir. For this implementation the MakeDir is always srcdir.

method read_configuration

Read information about the build process for this package. For this implementation, data is sought in the following locations in the following order: config.tcl (generated by practcl.) The Makefile

If the Makefile needs to be consulted, but does not exist, the Configure method is invoked

method build-cflags PROJECT DEFS namevar versionvar defsvar

method DEFS This method populates 4 variables: name - The name of the package version - The version of the package defs - C flags passed to the compiler includedir - A list of paths to feed to the compiler for finding headers

method critcl ?args?

Invoke critcl in an external process

Class practcl::toolset.msvc

ancestors: practcl::toolset


method BuildDir PWD

MSVC always builds in the source directory

method make {} autodetect

Do nothing

method make {} clean
method make {} compile
method make {} install DEST
method MakeDir srcdir

Detect what directory contains the Makefile template

method NmakeOpts

Class practcl::make_obj

ancestors: practcl::metaclass

A build deliverable object. Normally an object file, header, or tcl script which must be compiled or generated in some way


method constructor module_object name info ?action_body ?
method do
method check
method output
method reset
method triggers

Class practcl::object

ancestors: practcl::metaclass

A generic Practcl object


method constructor parent ?args?
method child method
method go

Class practcl::dynamic

Dynamic blocks do not generate their own .c files, instead the contribute to the amalgamation of the main library file


method cstructure name definition ?argdat ?

Parser functions

method include header
method include_dir ?args?
method include_directory ?args?
method c_header body
method c_code body
method c_function header body ?info ?
method c_tcloomethod name body ?arginfo ?
method cmethod name body ?arginfo ?

Alias to classic name

method c_tclproc_nspace nspace
method c_tclcmd name body ?arginfo ?
method c_tclproc_raw name body ?arginfo ?

Alias to classic name

method tcltype name argdat
method project-compile-products

Module interactions

method implement path
method initialize

Practcl internals

method linktype
method generate-cfile-constant
method generate-cfile-header
method generate-cfile-tclapi

Generate code that provides implements Tcl API calls

method generate-loader-module

Generate code that runs when the package/module is initialized into the interpreter

method Collate_Source CWD
method select

Once an object marks itself as some flavor of dynamic, stop trying to morph it into something else

Class practcl::product.cheader

ancestors: practcl::product

A product which generated from a C header file. Which is to say, nothing.


method project-compile-products
method generate-loader-module

Class practcl::product.csource

ancestors: practcl::product

A product which generated from a C source file. Normally an object (.o) file.


method project-compile-products

Class practcl::product.clibrary

ancestors: practcl::product

A product which is generated from a compiled C library. Usually a .a or a .dylib file, but in complex cases may actually just be a conduit for one project to integrate the source code of another


method linker-products configdict

Class practcl::product.dynamic

ancestors: practcl::dynamic practcl::product

A product which is generated from C code that itself is generated by practcl or some other means. This C file may or may not produce its own .o file, depending on whether it is eligible to become part of an amalgamation


method initialize

Class practcl::product.critcl

ancestors: practcl::dynamic practcl::product

A binary product produced by critcl. Note: The implementation is not written yet, this class does nothing.

Class practcl::module

ancestors: practcl::object practcl::product.dynamic

In the end, all C code must be loaded into a module This will either be a dynamically loaded library implementing a tcl extension, or a compiled in segment of a custom shell/app


variable make_object


method _MorphPatterns
method add ?args?
method install-headers ?args?
method make {} _preamble
method make {} pkginfo
method make {} objects

Return a dictionary of all handles and associated objects

method make {} object name

Return the object associated with handle name

method make {} reset

Reset all deputy objects

method make {} trigger ?args?

Exercise the triggers method for all handles listed

method make {} depends ?args?

Exercise the check method for all handles listed

method make {} filename name

Return the file name of the build product for the listed handle

method make {} task name Info ?body ?
method make {} todo

Return a list of handles for object which return true for the do method

method make {} do

For each target exercise the action specified in the action definition if the do method returns true

method child which
method generate-c

This methods generates the contents of an amalgamated .c file which implements the loader for a batch of tools

method generate-h

This methods generates the contents of an amalgamated .h file which describes the public API of this module

method generate-loader
method initialize
method implement path
method linktype

Class practcl::project

ancestors: practcl::module

A toplevel project that is a collection of other projects


method _MorphPatterns
method constructor ?args?
method add_object object
method add_project pkg info ?oodefine ?
method add_tool pkg info ?oodefine ?
method build-tclcore

Compile the Tcl core. If the define tk is true, compile the Tk core as well

method child which
method linktype
method project pkg ?args?

Exercise the methods of a sub-object

method tclcore
method tkcore
method tool pkg ?args?

Class practcl::library

ancestors: practcl::project

A toplevel project that produces a library


method clean PATH
method project-compile-products
method go
method generate-decls pkgname path
method implement path
method generate-make path

Backward compadible call

method linktype
method package-ifneeded ?args?

Create a "package ifneeded" Args are a list of aliases for which this package will answer to

method shared_library ?filename ?
method static_library ?filename ?

Class practcl::tclkit

ancestors: practcl::library

A toplevel project that produces a self-contained executable


method build-tclkit_main PROJECT PKG_OBJS
method Collate_Source CWD
method wrap PWD exename vfspath ?args?

Wrap an executable

Class practcl::distribution.snapshot

ancestors: practcl::distribution

A file distribution from zip, tarball, or other non-scm archive format

Class Methods

classmethod claim_object object
classmethod claim_option
classmethod claim_path path


method ScmUnpack

Class practcl::distribution.fossil

ancestors: practcl::distribution

A file distribution based on fossil

Class Methods

classmethod claim_object obj

Check for markers in the metadata

classmethod claim_option
classmethod claim_path path

Check for markers in the source root


method scm_info
method ScmClone

Clone the source

method ScmTag
method ScmUnpack
method ScmUpdate

Class practcl::subproject

ancestors: practcl::module

A subordinate project


method _MorphPatterns
method BuildDir PWD
method child which
method compile
method go
method install ?args?

Install project into the local build system

method linktype
method linker-products configdict
method linker-external configdict
method linker-extra configdict
method env-bootstrap

Methods for packages/tools that can be downloaded possibly built and used internally by this Practcl process Load the facility into the interpreter

method env-exec

Return a file path that exec can call

method env-install

Install the tool into the local environment

method env-load

Do whatever is necessary to get the tool into the local environment

method env-present

Check if tool is available for load/already loaded

method sources
method update
method unpack

Class practcl::subproject.source

ancestors: practcl::subproject practcl::library

A project which the kit compiles and integrates the source for itself


method env-bootstrap
method env-present
method linktype

Class practcl::subproject.critcl

ancestors: practcl::subproject


method install DEST

Class practcl::subproject.tea

ancestors: practcl::subproject.binary

A subordinate TEA based binary package

Class practcl::subproject.library

ancestors: practcl::subproject.binary practcl::library

A subordinate C library built by this project


method install DEST

Class practcl::subproject.external

ancestors: practcl::subproject.binary

A subordinate external C library


method install DEST

Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category practcl of the Tcllib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

When proposing code changes, please provide unified diffs, i.e the output of diff -u.

Note further that attachments are strongly preferred over inlined patches. Attachments can be made by going to the Edit form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar.