debian man page for mmap_shared

mmap_shared(3)						     Library Functions Manual						    mmap_shared(3)

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)