pos

See the current Perl documentation for pos.

Here is our local, out-dated (pre-5.6) version:

pos - find or set the offset for the last/next m//g search

pos SCALAR

pos

Returns the offset of where the last m//g search left off for the variable is in question ($_ is used when the variable is not specified). May be modified to change that offset. Such modification will also influence the \G zero-width assertion in regular expressions. See the perlre manpage and the perlop manpage.