Since this is a Perl site, here's a Perl solution (see perlrun): 
tail -f access | perl -ne 'print if /mod/i and /del/i'

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In the future, please use code tags for your code. See Writeup Formatting Tips.

In reply to Re: what is grep command for and condition by toolic
in thread OT: what is grep command for and condition by anakin30

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