recv SOCKET,SCALAR,LENGTH,FLAGS Receives a message on a socket. Attempts to receive LENGTH characters of data into variable SCALAR from the specified SOCKET filehandle. SCALAR will be grown or shrunk to the length actually read. Takes the same flags as the system call of the same name. Returns the address of the sender if SOCKET's protocol supports this; returns an empty string otherwise. If there's an error, returns the undefined value. This call is actually implemented in terms of recvfrom(2)

NAME SYNOPSIS DESCRIPTION'taint' mode 'eval' mode 'strict' mode '/flags' mode 'debug' mode 'Debug' mode Exportable Functions SEE ALSO NAME re - Perl pragma to alter regular expression behaviour SYNOPSIS use re 'taint'; ($x) = ($^X =~ /^(.*)$/s); # $x is tainted here $pat = '(?{ $foo = 1 })'; use re 'eval'; /foo${pat}bar/; # won't fail (when not under -T # switch) { no re 'taint'; # the default ($x) = ($^X =~ /^(.*)$/s); # $x

readdir DIRHANDLE Returns the next directory entry for a directory opened by opendir. If used in list context, returns all the rest of the entries in the directory. If there are no more entries, returns the undefined value in scalar context and the empty list in list context. If you're planning to filetest the return values out of a readdir, you'd better prepend the directory in question. Otherwise, because we didn't chdir there, it would have been testing the wrong file. opendir(my $dh, $some_

read FILEHANDLE,SCALAR,LENGTH,OFFSET read FILEHANDLE,SCALAR,LENGTH Attempts to read LENGTH characters of data into variable SCALAR from the specified FILEHANDLE. Returns the number of characters actually read, 0 at end of file, or undef if there was an error (in the latter case $! is also set). SCALAR will be grown or shrunk so that the last character actually read is the last character of the scalar after the read. An OFFSET may be specified to place the read data at some place in the string o

Range Operators Binary ".." is the range operator, which is really two different operators depending on the context. In list context, it returns a list of values counting (up by ones) from the left value to the right value. If the left value is greater than the right value then it returns the empty list. The range operator is useful for writing foreach (1..10) loops and for doing slice operations on arrays. In the current implementation, no temporary array is created when the range operator is

qx/STRING/ Generalized quotes. See Quote-Like Operators in perlop.

qw/STRING/

rand EXPR rand Returns a random fractional number greater than or equal to 0 and less than the value of EXPR. (EXPR should be positive.) If EXPR is omitted, the value 1 is used. Currently EXPR with the value 0 is also special-cased as 1 (this was undocumented before Perl 5.8.0 and is subject to change in future versions of Perl). Automatically calls srand unless srand has already been called. See also srand. Apply int() to the value returned by rand() if you want random integers instead of rand

quotemeta EXPR quotemeta Returns the value of EXPR with all the ASCII non-"word" characters backslashed. (That is, all ASCII characters not matching /[A-Za-z_0-9]/ will be preceded by a backslash in the returned string, regardless of any locale settings.) This is the internal function implementing the \Q escape in double-quoted strings. (See below for the behavior on non-ASCII code points.) If EXPR is omitted, uses $_ . quotemeta (and \Q ... \E ) are useful when interpolating strings into regul

Quote and Quote-like Operators While we usually think of quotes as literal values, in Perl they function as operators, providing various kinds of interpolating and pattern matching capabilities. Perl provides customary quote characters for these behaviors, but also provides a way for you to choose your quote character for any of them. In the following table, a {} represents any pair of delimiters you choose. Customary Generic Meaning Interpolates '' q{} Literal no ""