Tcl Cheat Sheet

email Scott Turner

variables `$a` `set a {a string}` `global a` Use a global variable within a procedure.	comments `# a comment` `set a $b ;# not much to say about this`
generic expression `$a ? $b : $c`	arithmetic Basic arithmetic uses the `expr` command. `expr 44*4`
strings `{what ever}` `$a$b` concatenation `string length $a` `string compare $a $b` returns 1, 0, or -1.	numbers `$a + $b` `$a - $b` `- $a` `$a * $b` `$a / $b` `abs($a)` `exp($a)` `pow($base,$exp)` `sin($a)` [etc.]
lists `list $elem1 $elem2` `concat $list1 $list2` `lappend listvarname $newelem` `lindex $list $n` nth element `llength $list` `concat $list1 $list2`	functions [foo 1 {a b c}] proc foo {x y} { action1 action2 return ... $x ... }
sentences `0` false Anything but `0` is taken as true. `$a == $b` numeric `$a != $b` numeric `$a != $b` numeric `$a < $b` numeric `$a <= $b` numeric `$a >= $b` numeric `$a > $b` numeric `$a && $b` logical `$a \|\| $b` logical `! $a` logical	actions `set a 44` `foo 1 {a b c}` `proc` is an action. if {$s} { action1 } elseif {$t} { action2 } else { action3 } while {$s} { action } foreach user $users { action }

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