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mmap_shared(3)        DragonFly 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)