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library(n)		     Tcl Built-In Commands		    library(n)


       auto_execok,   auto_import,   auto_load,	  auto_mkindex,	 auto_qualify,
       auto_reset,	 tcl_findLibrary,	 parray,	tcl_endOfWord,
       tcl_startOfNextWord,    tcl_startOfPreviousWord,	   tcl_wordBreakAfter,
       tcl_wordBreakBefore - standard library of Tcl procedures

       auto_execok cmd
       auto_import pattern
       auto_load cmd
       auto_mkindex dir pattern pattern ...
       auto_qualify command namespace
       tcl_findLibrary basename version patch initScript enVarName varName
       parray arrayName
       tcl_endOfWord str start
       tcl_startOfNextWord str start
       tcl_startOfPreviousWord str start
       tcl_wordBreakAfter str start
       tcl_wordBreakBefore str start

       Tcl includes a library of Tcl procedures for commonly-needed functions.
       The procedures defined in the Tcl library are generic ones suitable for
       use by many different applications.  The location of the Tcl library is
       returned	 by the info library command.  In addition to the Tcl library,
       each application will normally have its own library of  support	proce‐
       dures  as  well;	 the location of this library is normally given by the
       value of the $app_library global variable, where app is the name of the
       application.   For  example,  the location of the Tk library is kept in
       the variable tk_library.

       To access the procedures in the	Tcl  library,  an  application	should
       source  the file init.tcl in the library, for example with the Tcl com‐

	      source [file join [info library] init.tcl]

       If the library procedure Tcl_Init  is  invoked  from  an	 application's
       Tcl_AppInit   procedure,	 this  happens	automatically.	 The  code  in
       init.tcl will define the unknown procedure and arrange  for  the	 other
       procedures to be loaded on-demand using the auto-load mechanism defined

       The following procedures are provided in the Tcl library:

       auto_execok cmd
	      Determines whether there is an executable file or shell  builtin
	      by  the  name  cmd.  If so, it returns a list of arguments to be
	      passed to exec to execute the executable file or	shell  builtin
	      named by cmd.  If not, it returns an empty string.  This command
	      examines the directories in the current search  path  (given  by
	      the  PATH	 environment variable) in its search for an executable
	      file named cmd.  On Windows platforms, the  search  is  expanded
	      with  the	 same directories and file extensions as used by exec.
	      Auto_execok remembers information about previous searches in  an
	      array  named  auto_execs;	 this avoids the path search in future
	      calls for the same cmd.  The command auto_reset may be  used  to
	      force auto_execok to forget its cached information.

       auto_import pattern
	      Auto_import  is  invoked	during	namespace import to see if the
	      imported commands specified by pattern reside in	an  autoloaded
	      library.	 If  so,  the commands are loaded so that they will be
	      available to the interpreter for creating the import links.   If
	      the commands do not reside in an autoloaded library, auto_import
	      does nothing.  The pattern matching is  performed	 according  to
	      the matching rules of namespace import.

       auto_load cmd
	      This  command  attempts to load the definition for a Tcl command
	      named cmd.  To do this, it searches an auto-load path, which  is
	      a	 list of one or more directories.  The auto-load path is given
	      by the global variable auto_path if it exists.  If there	is  no
	      auto_path	 variable, then the TCLLIBPATH environment variable is
	      used, if it exists.  Otherwise the auto-load  path  consists  of
	      just  the	 Tcl  library directory.  Within each directory in the
	      auto-load path there must be a file tclIndex that describes  one
	      or more commands defined in that directory and a script to eval‐
	      uate to load each of the commands.  The tclIndex file should  be
	      generated	 with the auto_mkindex command.	 If cmd is found in an
	      index file, then the appropriate script is evaluated  to	create
	      the  command.   The  auto_load command returns 1 if cmd was suc‐
	      cessfully created.  The command returns 0 if there was no	 index
	      entry for cmd or if the script did not actually define cmd (e.g.
	      because index information is out of date).  If an	 error	occurs
	      while  processing	 the  script,  then  that  error  is returned.
	      Auto_load only reads the index information once and saves it  in
	      the  array  auto_index;  future calls to auto_load check for cmd
	      in the array rather than re-reading the index files.  The cached
	      index  information  may  be deleted with the command auto_reset.
	      This will force the next auto_load command to reload  the	 index
	      database from disk.

       auto_mkindex dir pattern pattern ...
	      Generates	 an  index suitable for use by auto_load.  The command
	      searches dir for all files whose names match any of the  pattern
	      arguments (matching is done with the glob command), generates an
	      index of all the Tcl  command  procedures	 defined  in  all  the
	      matching files, and stores the index information in a file named
	      tclIndex in dir. If no pattern is given a pattern of *.tcl  will
	      be assumed.  For example, the command

		     auto_mkindex foo *.tcl

	      will  read all the .tcl files in subdirectory foo and generate a
	      new index file foo/tclIndex.

	      Auto_mkindex parses the Tcl scripts  by  sourcing	 them  into  a
	      slave interpreter and monitoring the proc and namespace commands
	      that  are	 executed.   Extensions	 can  use  the	(undocumented)
	      auto_mkindex_parser  package to register other commands that can
	      contribute to the auto_load index. You will have to read through
	      auto.tcl to see how this works.

	      Auto_mkindex_old	(which	has  the  same syntax as auto_mkindex)
	      parses the Tcl scripts in a relatively unsophisticated way:   if
	      any  line	 contains the word “proc” as its first characters then
	      it is assumed to be a procedure definition and the next word  of
	      the  line	 is  taken as the procedure's name.  Procedure defini‐
	      tions that do not appear in  this	 way  (e.g. they  have	spaces
	      before  the  proc) will not be indexed.  If your script contains
	      “dangerous” code, such as global initialization code  or	proce‐
	      dure  names  with	 special characters like $, *, [ or ], you are
	      safer using auto_mkindex_old.

	      Destroys	all  the  information  cached	by   auto_execok   and
	      auto_load.   This information will be re-read from disk the next
	      time it is  needed.   Auto_reset	also  deletes  any  procedures
	      listed in the auto-load index, so that fresh copies of them will
	      be loaded the next time that they are used.

       auto_qualify command namespace
	      Computes a list of fully qualified names for command.  This list
	      mirrors  the path a standard Tcl interpreter follows for command
	      lookups:	first it looks for the command in the  current	names‐
	      pace, and then in the global namespace.  Accordingly, if command
	      is relative and namespace is not ::, the list returned  has  two
	      elements:	  command scoped by namespace, as if it were a command
	      in the namespace namespace; and command as if it were a  command
	      in  the global namespace.	 Otherwise, if either command is abso‐
	      lute (it begins with ::), or namespace is ::, the list  contains
	      only command as if it were a command in the global namespace.

	      Auto_qualify is used by the auto-loading facilities in Tcl, both
	      for producing auto-loading indexes such as pkgIndex.tcl, and for
	      performing the actual auto-loading of functions at runtime.

       tcl_findLibrary basename version patch initScript enVarName varName
	      This is a standard search procedure for use by extensions during
	      their initialization.  They call	this  procedure	 to  look  for
	      their  script library in several standard directories.  The last
	      component of the name of the library directory is normally base‐
	      nameversion (e.g., tk8.0), but it might be “library” when in the
	      build hierarchies.  The initScript file will be sourced into the
	      interpreter  once it is found.  The directory in which this file
	      is found is stored into the global variable  varName.   If  this
	      variable	is already defined (e.g., by C code during application
	      initialization) then no searching is done.  Otherwise the search
	      looks  in these directories: the directory named by the environ‐
	      ment variable enVarName; relative to the Tcl library  directory;
	      relative to the executable file in the standard installation bin
	      or bin/arch directory; relative to the executable	 file  in  the
	      current  build tree; relative to the executable file in a paral‐
	      lel build tree.

       parray arrayName
	      Prints on standard output the names and values of all  the  ele‐
	      ments in the array arrayName.  ArrayName must be an array acces‐
	      sible to the caller of  parray.	It  may	 be  either  local  or

       tcl_endOfWord str start
	      Returns  the index of the first end-of-word location that occurs
	      after a starting index start in the string str.  An  end-of-word
	      location is defined to be the first non-word character following
	      the first word character after the starting point.   Returns  -1
	      if  there	 are  no more end-of-word locations after the starting
	      point.  See the description of  tcl_wordchars  and  tcl_nonword‐
	      chars below for more details on how Tcl determines which charac‐
	      ters are word characters.

       tcl_startOfNextWord str start
	      Returns the index	 of  the  first	 start-of-word	location  that
	      occurs after a starting index start in the string str.  A start-
	      of-word location is defined to be the first word character  fol‐
	      lowing  a	 non-word  character.  Returns -1 if there are no more
	      start-of-word locations after the starting point.

       tcl_startOfPreviousWord str start
	      Returns the index	 of  the  first	 start-of-word	location  that
	      occurs before a starting index start in the string str.  Returns
	      -1 if there are  no  more	 start-of-word	locations  before  the
	      starting point.

       tcl_wordBreakAfter str start
	      Returns  the index of the first word boundary after the starting
	      index start in the string str.  Returns -1 if there are no  more
	      boundaries  after	 the  starting point in the given string.  The
	      index returned refers to the second character of the  pair  that
	      comprises a boundary.

       tcl_wordBreakBefore str start
	      Returns the index of the first word boundary before the starting
	      index start in the string str.  Returns -1 if the