Perl Programming/Keywords/read

The read keyword
read is a function that attempts to read LENGTH characters of data into variable SCALAR from the specified FILEHANDLE. If OFFSET is specified, it skips the number of OFFSET characters. It returns the number of characters actually read. If the end of file is reached, 0 is returned. On an error <tt>undef</tt> is returned and <tt>$!</tt> is also set.

<tt>read</tt> is unfortunately  not  the opposite of <tt>write</tt>.