My regexp is not working - regex

Question

I want to extract the error_name, Severity and Occurrences.
Here is the snippet of my report:
error_name: xxxxxxxxxx
Severity: Warning Occurrence: 2
error_name2:xxxxxxxxxxx.
Severity: Warning Occurrence: 16
error_name3:xxxxxxxxxxxxx
Severity: Warning Occurrence: 15
I am trying
while { [ gets $fp line ] >= 0 } {
if { [ regexp {^([^:\s]):.+^Severity:\s+Warning\s+Occurrence:\s+\d+} $line match errName count] } {
puts $errName
puts $count
incr errCount $count
}
But it does not write anything.

Answer 1

I would write this:
set fid [open filename r]
while {[gets $fid line] != -1} {
foreach {match label value} [regexp -inline -all {(\w+):\s*(\S*)} $line] {
switch -exact -- $label {
Severity {set sev $value}
Occurrence {set count $value}
default {set err $label}
}
}
if {[info exists err] && [info exists sev] && [info exists count]} {
puts $err
puts $count
incr errCount $count
unset err count sev
}
}
puts $errCount
error_name
2
error_name2
16
error_name3
15
33

Answer 2

If you can hold the entire file in memory at once (depends on how big it is relative to how much memory you've got) then you can use a piece of clever RE trickery to pick everything out:
# Load the whole file into $data
set f [open $filename]
set data [read $f]
close $f
# Store the RE in its own variable for clarity
set RE {^(\w+):.*\nSeverity: +(\w+) +Occurrence: +(\d+)$}
foreach {- name severity occur} [regexp -all -inline -line $RE $data] {
# Do something with each thing found
puts "$name - $severity - $occur"
}
OK, now to explain. The key is that we're parsing the whole string at once, but we're using the -line option so that ^ and $ become line-anchors and . won't match a newline. Apart from that, the -all -inline does what it says: returns a list of everything found, matches and submatches. We then iterate over that with foreach (the - is an odd variable name, but it's convenient for a “dummy discard”). This keeps the majority of the complicated string parsing in the RE engine rather than trying to do stuff in script.
You'll get better performance if you can constrain the start of the RE better than “word starting at line start” (as you can stop parsing a line sooner and continue to the next one) but if that's what your data is, that's what your data is.