Note that you can't modify your caller's environment variables directly. If you write this in perl:

$ENV{PATH} = "/home/abc/xyz/bin:$ENV{PATH}";
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It will only affect programs you call from that perl script.

The standard way of altering your caller's environment is to emit shell code, and evaluate that:

# my_env.pl
#!/usr/bin/perl
print q{export PATH=/home/abc/xyz/bin:$PATH}, "\n";

# and this is how you call it:
$ eval `./my_env.pl`
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