library man page on DigitalUNIX

Man page or keyword search:  
man Server   12896 pages
apropos Keyword Search (all sections)
Output format
DigitalUNIX logo
[printable version]

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

______________________________________________________________________________

NAME
       library - standard library of Tcl procedures

SYNOPSIS
       auto_execok cmd
       auto_load cmd
       auto_mkindex dir pattern pattern ...
       auto_mkindex_old dir pattern pattern ...
       auto_reset
       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					       │
_________________________________________________________________

INTRODUCTION
       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‐
       mand
	      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
       below.

COMMAND PROCEDURES
       The following procedures are provided in the Tcl library:

       auto_execok cmd
	      Determines  whether there is an executable file by the name cmd.
	      This command examines the directories in the current search path
	      (given  by  the PATH environment variable) to see if there is an
	      executable file named cmd in any of those directories.   If  so,
	      it  returns 1;  if not it returns 0.  Auto_exec remembers infor‐
	      mation 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  for‐
	      get its cached information.

       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 didn't 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 init.tcl to see how this works.

	      Auto_mkindex_old	parses	the  Tcl scripts in a relatively unso‐
	      phisticated 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	 definitions  that don't appear in this way (e.g. they
	      have spaces before the proc) will not be indexed.

       auto_reset
	      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're used.

       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
	      global.

       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 there are no more │
	      boundaries before the starting point in the given	 string.   The │
	      index  returned  refers to the second character of the pair that │
	      comprises a boundary.

VARIABLES
       The following global variables are defined or used by the procedures in
       the Tcl library:

       auto_execs
	      Used by auto_execok to record information about whether particu‐
	      lar commands exist as executable files.

       auto_index
	      Used by auto_load to save the index information read from disk.

       auto_noexec
	      If set to any value, then unknown will not attempt to  auto-exec
	      any commands.

       auto_noload
	      If  set to any value, then unknown will not attempt to auto-load
	      any commands.

       auto_path
	      If set, then it must contain a valid Tcl list giving directories
	      to  search  during  auto-load operations.	 This variable is ini‐
	      tialized during startup to contain, in  order:  the  directories
	      listed  in  the  TCLLIBPATH  environment variable, the directory
	      named by the $tcl_library	 variable,  the	 parent	 directory  of
	      $tcl_library,  the  directories listed in the $tcl_pkgPath vari‐
	      able.

       env(TCL_LIBRARY)
	      If set, then it specifies the location of the directory contain‐
	      ing library scripts (the value of this variable will be assigned
	      to the tcl_library variable and therefore returned by  the  com‐
	      mand  info  library).  If this variable isn't set then a default
	      value is used.

       env(TCLLIBPATH)
	      If set, then it must contain a valid Tcl list giving directories
	      to  search  during  auto-load operations.	 This variable is only
	      used when initializing the auto_path variable.

       tcl_nonwordchars
	      This variable contains a regular expression that is used by rou‐ │
	      tines like tcl_endOfWord to identify whether a character is part │
	      of a word or not.	 If the pattern matches a character, the char‐ │
	      acter  is	 considered  to	 be  a non-word character.  On Windows │
	      platforms, spaces, tabs, and newlines  are  considered  non-word │
	      characters.   Under  Unix,  everything  but numbers, letters and │
	      underscores are considered non-word characters.		       │

       tcl_wordchars							       │
	      This variable contains a regular expression that is used by rou‐ │
	      tines like tcl_endOfWord to identify whether a character is part │
	      of a word or not.	 If the pattern matches a character, the char‐ │
	      acter  is	 considered  to be a word character.  On Windows plat‐ │
	      forms, words are comprised of any character that is not a space, │
	      tab,  or	newline.   Under Unix, words are comprised of numbers, │
	      letters or underscores.

       unknown_active
	      This variable is set by unknown to indicate that it  is  active.
	      It is used to detect errors where unknown recurses on itself in‐
	      finitely.	 The variable is unset before unknown returns.

KEYWORDS
       auto-exec, auto-load, library, unknown, word, whitespace

Tcl				      8.0			    library(n)
[top]

List of man pages available for DigitalUNIX

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net