NAME

       mmap_shared - memory map a file for reading and writing

SYNTAX

       #include <mmap.h>

       char* mmap_shared(const char* filename,size_t* filesize);

DESCRIPTION

       mmap_shared  opens  filename  for  reading  and  writing, maps the whole file into memory,
       closes the file, writes the length of the file to filesize and returns a  pointer  to  the
       mapped file.

       The  file is mapped shared.  Changes done to the mapped region are written to disk and are
       visible to other processes reading from the file or mapping the same file into memory.

       The file is unmapped by the operating system if the process terminates.  It  can  also  be
       manually unmapped by calling munmap from <sys/mman.h>.

       To write changes to disk immediately, you can use msync from <sys/mman.h>.

       If the file could not be opened or mapped, (void*)0 is returned.

SEE ALSO

       mmap_unmap(3), msync(2)

                                                                                   mmap_shared(3)