Anirban Adhikary wrote:
> Dear list
> I want to sort a file which contains the following data.
>
> SUDIP,PQR,OFFICER,15000
> DIPAK,ABC,CLERK,7500
> CHANDAN,MNP,MANAGER,12000
> WASIM,PQR,CLERK,12000
> PROTIK,XYZ,MANAGER,14000
> DIPAK,XYZ,ADMIN,17000
>
>
> now I have written a program which will sort the file based on column 1,
> column 2 and column 3
>
> use strict;
> use warnings;
> my $fname="/USERS/anadhikary/test_prog/sort.txt";
> open my $DATA,'<',$fname;
> my @a = map { [ split "," ] } <$DATA>;
> close($DATA);
>
> print map { join ",", @$_ } sort {
> $a->[0] cmp $b->[0] or
> $a->[1] cmp $b->[1] or
> $a->[2] cmp $b->[2]
> } @a;
>
> This program works fine. But my question is the columns on which I am
> sorting is hard coded. But I want to make the program dynamic.
> This file has 4 columns but It can always happen that file has 15 columns
> and I need to sort on 8 columns among the 15 columns.
> Suppose the user who runs the program is passing the number of column names
> as an program argument (for example ./sort.pl 4 5 7 8 12 13 15).
>
> So this condition how can be implemented through this program?
>
> I have tried in the following way
> [anadhik...@strawberry test_prog]$ ./sort.pl 1 2 3
> the code is as follows(changed part)
>
>
> for(my $i=0;$i<=$#ARGV;$i++){
> my $val=$ARGV[$i];
> $str_name.="\$a->[".$val."] cmp \$b->[".$val."] or"."\n";;
> }
> $str_name=substr($str_name,0,-3);
>
> print map { join ",", @$_ } sort {
> "$str_name"
> }...@a;
>
> ## the $str_name prints#####
> $a->[1] cmp $b->[1] or
> $a->[2] cmp $b->[2] or
> $a->[3] cmp $b->[3]
> ########################
> But when I run the program this gives following error
>
> Sort subroutine didn't return a numeric value at test1.pl line 28
>
> Please Suggest....................
This will do what you reguire. I hope it helps.
Rob
print
map { join ',', @$_ }
sort {
my $cmp = 0;
foreach (@ARGV) {
my $i = $_ - 1;
last if $cmp= $a->[$i] cmp $b->[$i];
}
$cmp;
}
map { [ split /,/ ] } <$DATA>;
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