I have following code:
set variable1 "5"
set variable2 "6-7"
if {[regexp {md+M} $variable1 matchall]} {
puts "only a number has been provided and that is $matchall"
}
if {[regexp {md+M} $variable2 matchall]} {
puts "only a number has been provided and that is $matchall"
}
Basically, i want to only match variable1 which is just a number. variable2 does have a hyphen inside which should not match because i am using the m and M which are basically doing the same as b in normal regex which indicates word boundaries. So when i run the code i get:
only a number has been provided and that is 5
only a number has been provided and that is 6
can anyone give me tip in the right direction? I am stuck with TCL 8.3 and cannot upgrade. But regex should basically work the same way as with never versions.
2
You need to anchor the regexp to make it match the entire string, not a part of the string.
if {[regexp {^d+$} $variable2 matchall]} {
puts "only a number has been provided and that is $matchall"
}
There’s no need for word boundaries since the ends of the strings are also boundaries.
In addition to Barmar’s answer, it is worth noting that you do not need a regular expression here. Just test with the string command:
string is integer -strict $s
This permits leading and trailing whitespace, though. If that is significant, you can trim it away with
string trim $s
before using it anywhere. To wit:
if {[string is integer -strict $variable1]} {
puts "only a number has been provided and that is [string trim $variable1]"
}