$_ = "one\ttwo\nthree four five\r";

s/(\t)|(\n)|(\r)|(\f)/
    ($1 && '\t' || '')
    . ($2 && '\n' || '')
    . ($3 && '\r' || '')
    . ($4 && '\f' || '')
/ge;

[download]
Update: 
$_ = "one\ttwo\nthree four five\r";

s/(\t)|(\n)|(\r)|(\f)/
    $1 ? '\t' :
    $2 ? '\n' :
    $3 ? '\r' :
    $4 ? '\f' :
    ''
/ge;

[download]

Makeshifts last the longest.

In reply to Re: Can this be a 1 line or simpler regex? by Aristotle
in thread Can this be a 1 line or simpler regex? by smackdab

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