sed in perl

[GauCho]

Hi All, i have a problem with using sed in a perl script. Requirement: Read a csv file (file1) containing certain pattern, match the pattern in another text file (file2) and delete it where ever its occurring.

file1:

abc/def
sde/dfg/htf

file2:

abc/def = 100
sde/dfg/htf = 230
dad/fry = 000

in the end only dad/fry = 000 should remain in file2.

I cannot install any package, so have to use the default perl options.

Since my file1 contains special character "/" , i have escaped it in my code.

my sed command is working fine if I try to run it without loop, i.e for one pattern only. As soon as I add it in loop, it fails.

my code:

my $var = "sde\\/dfg\\/htf";
`sed -i '/$var/d' ADT_DVEBMGS33_ldciadt`;

The above works fine.

i tried to encorporate in a loop

my $len = scalar @delete;
for ( my $i = 0; $i <=$len; $i++){
        my $first = $delete[$i];
        chomp $first;
        $first =~ s:/:\\\\/:g;
        `sed -i "/$first/d" file2`;
}

error

<c> sed: -e expression #1, char 10: extra characters after command sed: -e expression #1, char 0: no previous regular expression

[Corion]

Why are you using sed when you can use Perl directly?

open my $fh1, '<', "file1"
    or die "Couldn't read 'file1': $!";
my %delete = map { s/\s*$//; $_ => 1 } <$fh1>;

open my $fh2, '<', "file2"
    or die "Couldn't read 'file2': $!";
while( <$fh2>) {
    my( $key, $value ) = split /\s*=/;
    if( ! $delete{ $key }) {
        print $_;
    } else {
        # skip this key
    };
};

If you want to keep on using sed, my advice is to print all the commands you're launching and then inspecting them or running them from the command line separately.

[GauCho]

I tried printing the sed command and to my surprise, sed is not working as expected. i get "/d' <file2>" as command and sed is nowhere part of the command. i will try out the perl code!

[Anonymous Monk]

Hi. Why not write the whole enchilada in sed? I mean come on very much. ;). Csv is too complexed for sed. https://metacpan.org/pod/Text::CSV_XS#The-examples-folder, Basic debugging checklist, String::ShellQuote , sed isn't working within a perl script