XPS-Q8
Tcl Manual
Table of Contents
1.0
TCP/IP Communication............................................................................... 1
2.0
Tool Command Language............................................................................ 2
2.1
Introduction ............................................................................................................................. 2
2.2
Tcl scripting language features ................................................................................................ 2
2.2.1
“Hello, World!” example ..................................................................................... 2
2.2.2
Variables .............................................................................................................. 3
2.2.3
Command Substitution ......................................................................................... 3
2.2.4
Math Expressions ................................................................................................. 4
2.2.5
Backslash Substitution ......................................................................................... 4
2.2.6
Grouping with Braces and Double Quotes ........................................................... 5
2.2.6.1
Square Brackets Do Not Group ................................................ 6
2.2.6.2
Grouping before Substitution ................................................... 6
2.2.6.3
Grouping Math Expressions with Braces ................................. 7
2.2.6.4
More Substitution Examples .................................................... 7
2.2.7
Procedures ............................................................................................................ 7
2.2.8
A Factorial Example ............................................................................................ 8
2.2.9
More about Variables ........................................................................................... 9
2.2.9.1
Funny Variable Names ............................................................10
2.2.9.2
The unset Command................................................................10
2.2.9.3
Using info exists to check whether a variable exists ...............11
2.2.10
More about Math Expressions ......................................................................... 11
2.2.11
Comments ........................................................................................................ 12
2.2.12
Substitution and Grouping Summary ............................................................... 12
2.2.13
Fine Points ....................................................................................................... 13
2.3
Reference ............................................................................................................................... 14
2.3.1
Backslash Sequences ......................................................................................... 14
2.3.2
Arithmetic Operators ......................................................................................... 14
3.0
Tcl Script Execution at Boot ...................................................................... 15
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