String(3) User Contributed Perl Documentation String(3)
IO::String - Emulate file interface for in-core strings
$io = IO::String->new;
$io = IO::String->new($var);
tie *IO, 'IO::String';
# read data
read($io, $buf, 100);
# write data
print $io "string
syswrite($io, $buf, 100);
printf "Some text %s
$pos = $io->getpos;
$io->setpos(0); # rewind
seek($io, 0, 0);
The "IO::String" module provides the "IO::File" interface for in-core strings. An "IO::String" object can be attached to a string, and
makes it possible to use the normal file operations for reading or writing data, as well as for seeking to various locations of the string.
This is useful when you want to use a library module that only provides an interface to file handles on data that you have in a string
Note that perl-5.8 and better has built-in support for "in memory" files, which are set up by passing a reference instead of a filename to
the open() call. The reason for using this module is that it makes the code backwards compatible with older versions of Perl.
The "IO::String" module provides an interface compatible with "IO::File" as distributed with IO-1.20, but the following methods are not
available: new_from_fd, fdopen, format_write, format_page_number, format_lines_per_page, format_lines_left, format_name, format_top_name.
The following methods are specific to the "IO::String" class:
$io = IO::String->new
$io = IO::String->new( $string )
The constructor returns a newly-created "IO::String" object. It takes an optional argument, which is the string to read from or write
into. If no $string argument is given, then an internal buffer (initially empty) is allocated.
The "IO::String" object returned is tied to itself. This means that you can use most Perl I/O built-ins on it too: readline, <>, getc,
print, printf, syswrite, sysread, close.
$io->open( $string )
Attaches an existing IO::String object to some other $string, or allocates a new internal buffer (if no argument is given). The
position is reset to 0.
Returns a reference to the string that is attached to the "IO::String" object. Most useful when you let the "IO::String" create an
internal buffer to write into.
$io->pad( $char )
Specifies the padding to use if the string is extended by either the seek() or truncate() methods. It is a single character and
defaults to "