|
Command
|
Use
|
Example
|
| # |
Comment |
# One line
# Another one
|
| append |
append to end of variable value |
set foo "Hello "
append foo "World" |
| break |
exit loops |
|
| catch |
used to recover from errors |
catch {procedure} [var] |
| eval |
build and evaluate a Tcl command
before it is performed |
set fred "set flintstone
40"
eval $fred
40 |
| exec |
execute subprocesses, includes
external commands |
exec /usr/bin/ls -l |
| exit |
End a process |
|
| expr |
evaluate an expression, normally
arithmetic |
expr 2 + 2
expr 10 * 2 + $var
|
| file |
file I/O commands
Syntax: file keyword args
Includes commands such as read, write, etc. |
|
| for |
Definite looping construct |
for {set i 1} {$i <= 10} {incr i}
{
coded statements here
}
|
| foreach |
iterate over a list |
set var [list ferrari porsche skoda]
foreach car $var {
coded statements here
}
|
| format |
|
|
| global |
makes a global variable |
global domination
set domination "we will" |
|
Command
|
Use
|
Example
|
if
if/else |
conditional statement |
if { $var == 1 }
{
set iable 4
}
else
{
set iable 10
}
|
| incr |
increment value by one |
set bob 1
incr bob
# bob is now 2 |
| info |
various uses, but handy for checking
if variables already exist |
if { [info exists somevar]
} |
| join |
Joins a list of values together
given a punctuation character. |
|
| lappend |
Append a list of values to the
end of a variable |
set var1 [ list
5 ]
set var2 [ 10 15 20 ]
lappend var1 var2 |
| lindex |
extract an element from a list
given its position |
lindex $list_var 3 |
| linsert |
insert an element into a list |
|
| list |
take values and make a list |
set some_var [list
1 2 3] |
| llength |
list length |
llength $somelist |
| lrange |
|
|
| lreplace |
|
|
| lsort |
sort the list. Use flags to change
order and stuff |
|
| proc |
create a procedure |
proc thename { values }
{
somecode
}
|
