The Tcl library , a part of the Tcl core distribution, is a collection of procedures for commonly needed functions.
- official reference
- determines whether an executable file, or shell builtin, exists
- search for and load definitions for commands matching a specified patttern
- attempts to load the definition for a command
- generates an index suitable for use by auto_load, writing it to a file named tclIndex
- computes a list of fully-qualified names for a command
- destroys all the information cached by auto_execok and auto_load
- prints the names and values of the elments in an array
- a standard search procedure used by extensions during their initialization
- find the end of the specified word
- find the start of the next word
- find the start of the previous word
- find the beginning of word delimiter after the specified word
- find the beginning of the word delimiter before the specified word
The following global variables are defined or used by the procedures in the Tcl library.
- an array containing the names of commands that could not be located by auto_execok
- an array of names of commands known to auto_load
- If this variable is defined, unknown will not attempt to exec any unknown commands.
- If this variable is defined, unknown will not attempt to auto_load any commands
- a list of directories that package unknown searches to find package packages. The initial value of this variable aggregated from the value of the following sources, in order: $env(TCLLIBPATH), $tcl_library, the parent directory of $tcl_library, and $tcl_pkgPath.
- tcl_wordchars and tcl_nonwordchars
- Used by $tcl_endOfWord, tcl_startOfNextWord, tcl_startOfPreviousWord, tcl_wordBreakAfter, and tcl_wordBreakBefore commands. By default, these variables are not defined and the following rules apply: Under Unix, word characters are numbers, letters, and underscores ; under Windows, word characters are every character except space, tab, and newline.