分类: LINUX
2009-05-23 22:23:12
Tcl
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IntroductionAlthough
Tcl scripts/procedures can be controlled via graphical user interfaces
(GUI's) that have been implemented with the Tk toolkit, it is often
easier to use traditional command line techniques. Another tutorial, , gave a simple example of invoking a Tcl script from the command line. argumentsItems of data passed to a script from the command line are known as arguments. For example, take the simple script presented in tutorial. puts [expr 3 + 2] Lets assume the script has been saved as add.tcl and that the present working directory of the shell window in which we are working matches the directory in which the script has been saved. We know the script can be run using the following command, tclsh add.tcl Of course the output is always the same because the values being added are hard-coded into the script. The script would be more useful if we could pass values to the script from the command line. tclsh add.tcl 23 15
The method by which numbers can be passed into, and used by a script, is as follows. |
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argc argv argv0All Tcl scripts have access to three predefined variables. if { $argc != 2 } { The lindex command returns the first and second items from the list of arguments entered at the command line. Items in a list are counted from zero. |