In Linux you have mmap which is a system function built just for that purpose,of course there are wrappers in Perl that do that for you,like the one mentioned above. 
MMAP(2)                                                          Linux
+ Programmerâs Manual                                                 
+        MMAP(2)

NAME
       mmap, munmap - map or unmap files or devices into memory

DESCRIPTION
       mmap()  creates  a new mapping in the virtual address space of 
+the calling process.  The starting address for the new mapping is spe
+cified in addr.
       The length argument specifies the length of the mapping.

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In reply to Re^2: Most efficient way to load file contents into scalar? by spx2
in thread Most efficient way to load file contents into scalar? by smallwalrus

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