Perl first day
Perl acts like glue, gluing all languages together.
It's light and convenient, and it's very suitable for writing small scripts (I haven't written more than 1000 lines of perl code yet).
What I admire most is its powerful regular computing power, especially the "capture" operation, which is really amazing!
Based on the above characteristics, I think perl is very suitable for:
1. Text processing-- > powerful regular expressions
two。 Bonding between systems-- > glue language
For regular expressions, there are already many tutorials online, and I'll give you a few examples of my own practice:
1.
Open (my $in, ". / template.txt") or die "open error: $!"; / / Open a file
My @ lines
While () / / read in a line
{
For ($_) {/ / actually here practice using for is often implemented with foreach
/ apn_oi_replacement/ and do / / if apn_oi_replacement is matched, do something
{
Push (@ lines, scalar) for (1.. 3); / / read three lines
& processing_apn_oi_replacement (@ lines); / / A process these three lines
Print "* *" x 40. "\ n"
Last; / / jumps out of the loop, which is equivalent to break in C (don't do it later if you have a judgment)
}
}
two。
Foreach (@ _) / / traverses the entire array
{
If (/ FQDN:\ s + (. *?)\ nUniverse) / / here? The function of non-greedy matching / s is to make it possible to match.
{
$fqdn_apn_oi_replacement = $1
}
If (/ requested APN:\ s + (. *?)\ nUniverse)
{
$requestedapn_apn_oi_replacement = $1
}
}
NOTE: now I've only learned some very basic text processing methods, and I need to strengthen my practice so as not to forget!
