One way to do this is to use regular expressions, as in: 
#!/usr/local/bin/perl -w

use strict;
open FILE, "<input.txt" or die "Blerch: $!\n";
local $/=undef;
my $text=<FILE>;
close FILE;
print $text;
my @ands = $text =~/\b(and)\b/ig;
print scalar @ands;
__END__
But now I know that twenty centuries of stony sleep
were vexed to nightmare by a rocking cradle.
And what rough beast, it's hour come round at last,
slouches towards Betlehem to be born?

And the world turned around the sun.
2

[download]
Doing this for multiple files and multiple words is left as an exercise for the reader.

Have a look at perlre for more information on regular expressions.

CU
Robartes-

In reply to Re: How to count the total number of times the word 'the' and 'and' occur in 5 files i selected? by robartes
in thread How to count the total number of times the word 'the' and 'and' occur in 5 files i selected? by lingling

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