Awk Equivalent in perl

Question

I am understanding perl in command line, please help me

what is equivalent in perl

awk '{for(i=1;i<=NF;i++)printf i < NF ? $i OFS : $i RS}' file

awk '!x[$0]++' file

awk 'FNR==NR{A[$0];next}($0 in A)' file1 file2

awk 'FNR==NR{A[$1]=$5 OFS $6;next}($1 in A){print $0,A[$1];delete A[$1]}' file1 file1

Please someone help me...

Answer 1

Try the awk to perl translator. For example:

$ echo awk '!x[$0]++' file | a2p
#!/usr/bin/perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
    if $running_under_some_shell;
            # this emulates #! processing on NIH machines.
            # (remove #! line above if indigestible)

eval '$'.$1.'$2;' while $ARGV[0] =~ /^([A-Za-z_0-9]+=)(.*)/ && shift;
            # process any FOO=bar switches

while (<>) {
    chomp;  # strip record separator
    print $_ if $awk;print $_ if !($X{$_}++ . $file);
}

You can ignore the boiler plate at the beginning and see the meat of the perl in the while loop. The translation is seldom perfect (even in this simple example, the perl code omits newlines), but it usually provides a reasonable approximation.

Another example (the one Peter is having trouble with in the comments):

$ echo '{for(i=1;i<=NF;i++)printf( i < NF ? ( $i OFS ) : ($i RS))}'  | a2p
#!/usr/bin/perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
    if $running_under_some_shell;
            # this emulates #! processing on NIH machines.
            # (remove #! line above if indigestible)

eval '$'.$1.'$2;' while $ARGV[0] =~ /^([A-Za-z_0-9]+=)(.*)/ && shift;
            # process any FOO=bar switches

$, = ' ';       # set output field separator

while (<>) {
    chomp;  # strip record separator
    @Fld = split(' ', $_, -1);
    for ($i = 1; $i <= ($#Fld+1); $i++) {
    printf (($i < ($#Fld+1) ? ($Fld[$i] . $,) : ($Fld[$i] . $/)));
    }
}