See the current Perl documentation for symlink.
Here is our local, out-dated (pre-5.6) version:

symlink - create a symbolic link to a file

symlink OLDFILE,NEWFILE

Creates a new filename symbolically linked to the old filename. Returns 1 for success, 0 otherwise. On systems that don't support symbolic links, produces a fatal
error at run time. To check for that, use eval:
$symlink_exists = eval { symlink("",""); 1 };