if statement in TCL
set x 1
if {$x == 2} {puts "$x is 2"} else {puts "$x is not 2"}
if {$x != 1} {
puts "$x is != 1"
} else {
puts "$x is 1"
}
if $x==1 {puts "GOT 1"}
#
# Be careful, this is just an example
# Usually you should avoid such constructs,
# it is less than clear what is going on and it can be dangerous
#
set y x
if "$$y != 1" {
puts "$$y is != 1"
} else {
puts "$$y is 1"
}
#
# A dangerous example: due to the extra round of substitution,
# the script stops
#
set y {[exit]}
if "$$y != 1" {
puts "$$y is != 1"
} else {
puts "$$y is 1"
}