Table of Contents
The source command will load a file
and execute it. This allows a program to be broken up into multiple
files, with each file defining procedures and variables for a
particular area of functionality. For instance, you might have a
file called database.tcl that contains all the
procedures for dealing with a database, or a file called
gui.tcl that handles creating a graphical user
interface with Tk. The main script can then simply include each
file using the source command. More
powerful techniques for program modularization are discussed in the
next lesson on packages.
This command can be used to:
separate a program into multiple files.
make a library file that contains all the procs for a particular set of functions.
configure programs.
load data files.
source fileNameReads the script in fileName and
executes it. If the script executes successfully, source returns the value of the last statement in
the script.
If there is an error in the script, source will return that error.
If there is a return (other than within a proc definition) then source will return immediately, without executing
the remainder of the script.
If fileName starts with a tilde
(~) then $env(HOME) will substituted for
the tilde, as is done in the file
command.