UNIX for Dummies Questions & Answers

can any1 give me line by line explanation for the following perl script
as i dunno perl .. n i have searched in google .. but still thn i wanna confirm my findings fro perl experts

perl -e 'while (<>)
{
print;
$num = 2 if /fail_halt/i;
$num = 1 if (/failure/i && ($num < 1));
}
print $num
exit $num;'

wanna know this meaning .. as this perl script has been embedded in an unix script

help ASAP
thank you

perl -e 'while (<>)
{
print;
$num = 2 if /fail_halt/i;
$num = 1 if (/failure/i && ($num < 1));
}
print $num
exit $num;'

-e is a command line option
for example on terminal you can say perl -e 'print "Hello World\n";'

while(<>)
while is loop present in most languages u must be knowing and (<>) means it is reading standard input line by line

print;
meand it will standard input scalar i.e. $_ means the line itself which it reads

$num = 2 if /fail_halt/i;
setting the value of variable $num to 2 if line contains word "fail_halt" and i option is for ignoring the case of letters (FAIL_HALT or fail_HaLt)


$num = 1 if (/failure/i && ($num < 1));
setting the value of variable $num to 1 if line contains failure word

In last print $num and exit

hey jam_ali49
thnx a ton
i was not sure about the i option in if statement .. ur post clarified it