Manpages - PerlIO_scalar.3perl

PerlIO::scalar - in-memory IO, scalar IO

my $scalar = ; … open my $fh, “<”, \$scalar or die; open my $fh, “>”, \$scalar or die; open my $fh, “>>”, \$scalar or die;

or

my $scalar = ; … open my $fh, “<:scalar”, \$scalar or die; open my $fh, “>:scalar”, \$scalar or die; open my $fh, “>>:scalar”, \$scalar or die;

A filehandle is opened but the file operations are performed in-memory on a scalar variable. All the normal file operations can be performed on the handle. The scalar is considered a stream of bytes. Currently fileno($fh) returns -1.

Attempting to open a read-only scalar for writing will fail, and if warnings are enabled, produce a warning.

PerlIO::scalar only exists to use XSLoader to load C code that provides support for treating a scalar as an in memory file. One does not need to explicitly use PerlIO::scalar.