在TCL中匹配regexp的问题

Question

I am having following pattern

Notif[0]:
some text multiple line
Notif[1]:
multiple line text
Notif[2]:
text again
Notif[3]:
text again
Finish

I am writting following regexp

set notifList [regexp -inline -all -nocase {Notif\[\d+\].*?(?=Notif|Finish)} $var]

It is not giving desired output

Output needed

I need a list with each `Notif`block

Answer 1

The reason is that your .*? acts as a greedy subpattern (= .* matching 0+ any characters incl. a newline) because the first quantifier in the pattern was a greedy one (see \\d+ ). See this Tcl Regex reference :

A branch has the same preference as the first quantified atom in it which has a preference.

You need to just turn the first + quantified subpattern into a lazy one by adding a ? after it:

Notif\[\d+?\].*?(?=Notif|Finish)
          ^

This will prevent the .*? pattern to inherit the greediness from the \\d+ .

See the IDEONE demo