Rather than try to work directly with /etc/shadow have you considered using Perl to interface with PAM (pluggable authentication module for Linux)? There are several modules available on CPAN: PAM.

By going to etc/shadow directly you are bypassing whatever additional checks and validations or security alternatives have been configured for your system's users via PAM.

In reply to Re: Authentication with /etc/shadow by ELISHEVA
in thread Authentication with /etc/shadow by fluffyvoidwarrior

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