Perl: sorting by string

Shell Programming and Scripting
1

I have an array full of string values that need to be sorted, but if a value starts with (regex) 0^[SV] it should be at the beginning of the array. Otherwise the array should be sorted normally using ascii sort.

Please help me create the sub to pass to the sort function.

2

show some examples

3

It will look like this before:

and after

4

here's one idea
1) got through each element of the array, check for ^0[SV], if yes, push to array1. at the same time, those not ^0[SV] , push to array2
2) sort array1 ( using sort function), and array2
3) join the new arrays together, putting array2 behind array1

5

Write your own sort-sub, more in perldoc -f sort

6

Thanks. I figured it out.

sub Bysite {
    if ( $a =~ /^0[SV]/ ) {
        return -1;
    }
    elsif ( $b =~ /^0[SV]/ ) {
        return 1;
    }
    lc($a) cmp lc($b);
}

@array = sort Bysite @array;
7

Thats a good solution but it will not sort your sample array into what you posted:

0S09
0S22
0V54
0V72
0A13
0H98
0L43
EL24
STB45

it sorts a little differently:

0S22 <--
0S09 <--
0V54
0V72
0A13
0H98
0L43
EL24
STB45

but maybe close enough is OK :slight_smile:

8

Thanks. For this particular case, close enough is ok.