Programming Perl, 4th Edition

chomp

chomp VARIABLE
chomp LIST
chomp

This function (normally) deletes a trailing newline from the end of a string contained in a variable. This is a slightly safer version of chop (described next) in that it has no effect on a string that doesn’t end in a newline. More specifically, it deletes the terminating string corresponding to the current value of $/, and not just any last character.

Unlike chop, chomp returns the number of characters deleted. If $/ is "" (in paragraph mode), chomp removes all trailing newlines from the selected string (or strings, if chomping a LIST). When in slurp mode ($/ = undef) or fixed-length record mode ($/ is a reference to an integer), chomp does nothing. You cannot chomp a literal, only a variable. Chomping a hash chomps only the values, not the keys.

For example:

while (<PASSWD>) {
    chomp;   # avoid \n on last field
    @array = split /:/;
    ...
}

I/O layers are allowed to override the value of the $/ variable and mark how strings should be chomped. This has the advantage that an I/O layer can recognize more than one variety of line terminator (like the Unicode paragraph and line separators), but still safely chomp whatever terminates the current line.

The chomp function is not currently smart enough to handle Unicode linebreak sequences, whose regex metacharacter ...