Shell Programming and Scripting

awk -v var="name" -F"," ' $0 ~ var { for (i=1;i<=NF;i++) if ($i==var) idx=i} $0 !~ var { print $idx} ' file

#!/bin/ksh
IAm=${0##*/}
if [ $# -ne 2 ]
then    printf "Usage: %s input_file column_heading\n" "$IAm" >&2
        exit 1
fi
ef=_"$IAm$$"
if [ ! -f "$1" ] || [ ! -r "$1" ]
then
    printf "%s: input_file \"%s\" must be a readable regular file.\n" \
                "$IAm" "$1" >&2
        exit 2
fi
if ! awk -F, -v ch="$2" -v IAm="$IAm" -v ef="$ef" '
FNR == 1 {
        for(i = 1; i <= NF; i++)
                if($i == ch) break
        if(i > NF) {
                printf("%s: column_heading %s not found\n", IAm, ch) > ef
                exit 3
        }
        next
}
{       print $i}' "$1"
then    cat "$ef" >&2
        rm -f "$ef"
        exit 3
fi

chmod +x getf

getf input.csv marks

80
56
78

#!/usr/bin/perl -w
use strict;

my $cur_dir = $ENV{PWD};
my $filename = "$cur_dir/$ARGV[0]";

my ($record,@fields,$index);

open(FILE,"<$filename") or die"open: $!";
while( defined( $record = <FILE> ) ) {
  chomp $record;
  if ( $record =~ $ARGV[1] ) {
    @fields=split(/,/,$record);
    ($index) = grep { $fields[$_] eq $ARGV[1] } 0..$#fields;
    last
  }
}
close(FILE);

open(FILE,"<$filename") or die"open: $!";
while( defined( $record = <FILE> ) ) {
  chomp $record;
  if ( $record !~ $ARGV[1] ) {
    @fields=split(/,/,$record);
    print "$fields[$index]\n";
  }
}
close(FILE);

%./file018.pl file018 name
kevin
Satch
Meena

%./file018.pl file018 section
A
B
C