[EMAIL PROTECTED] wrote:
>
> Dear Perl experts,
>
> I'm trying to find the right regular expressions to do some simple (?)
> string processing. Can anyone tell me how to do these?
#!/usr/bin/perl -lw
use strict;
> 1. Given a string consisting of substrings delimited by colons, such as
> :B520:L201:M:M260:8:G607:, how can I
> a. remove the single-character and all-numeric substrings (M and 8 in
> this example), leaving the rest alone?
my $aa = ':B520:L201:M:M260:8:G607:';
my @bb = split /:/, $aa; #split on :
shift @bb; # remove the andef from before the first colon
my @answer1a = grep {!/^\w$|^\d+$/} @bb;
> b. remove all but the single-character and all-numeric substrings and
> leave the rest alone?
my @answer1b = grep { /^\w$|^\d+$/} @bb;
> c. remove all but single- or double-character substrings and
> all-numeric substrings and leave the rest alone?
> The string will never have regex metacharacters in it, just mixed alpha
> and numeric, all-alpha, or all-numeric. The colons can stay.
my @answer1c = grep { !/.|..|^\d+$/} @bb;
> 2. Is there an easy way to count the number of substrings (the "chunks"
> between colons)?
my $answer2 = @bb;
print "@[EMAIL PROTECTED]@bb\n$answer2\n";
> 3. This one is probably a bit difficult. I don't need to have it, but it
> would save me lots of effort if I had it. Given two strings of the same
> form as in no. 1, is there a regular expression which can compare the two
> and return the number of substring positions which have exact matches?
> I.e., given string 1 = :L000:W000:M:M260:G607: and string 2
> = :L001:W000:M:M261:M260: can match the substrings and their positions and
> return the result "2" in this case? The M260 substring is present in both
> but in different positions and shouldn't be counted as a match.
my @array;
while(<DATA>){
chomp;
@bb = split /:/, $_; #split on :
shift @bb; # remove the andef from before the first colon
push @array, [EMAIL PROTECTED];
}
my @answer;
foreach my $i (0..$#array){
foreach my $j ($i+1 .. $#array){
my $nr = 0;
my $k = 0;
while (exists $array[$i][$k] and exists $array[$j][$k]){
$nr++ if $array[$i][$k] eq $array[$j][$k];
$k++;
}
print "row $i and $j have $nr equal fields";
}
}
__DATA__
:L000:W000:M:M260:G607:
:L001:W000:M:M261:M260:
/Stefan
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