Unix/Linux Go Back    

CentOS 7.0 - man page for mmap2 (centos section 2)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

MMAP2(2)			    Linux Programmer's Manual				 MMAP2(2)

       mmap2 - map files or devices into memory

       #include <sys/mman.h>

       void *mmap2(void *addr, size_t length, int prot,
		    int flags, int fd, off_t pgoffset);

       This  is  probably  not	the  system  call you are interested; instead, see mmap(2), which
       describes the glibc wrapper function that invokes this system call.

       The mmap2() system call provides the same interface as  mmap(2),  except  that  the  final
       argument  specifies  the  offset into the file in 4096-byte units (instead of bytes, as is
       done by mmap(2)).  This enables applications that use a 32-bit off_t to	map  large  files
       (up to 2^44 bytes).

       On  success,  mmap2()  returns  a pointer to the mapped area.  On error -1 is returned and
       errno is set appropriately.

       EFAULT Problem with getting the data from user space.

       EINVAL (Various platforms where the page size is not 4096 bytes.)  offset * 4096 is not	a
	      multiple of the system page size.

       mmap2() can also return any of the errors described in mmap(2).

       mmap2() is available since Linux 2.3.31.

       This system call is Linux-specific.

       Nowadays,  the  glibc  mmap()  wrapper  function  invokes this system call rather than the
       mmap(2) system call.

       On ia64, the unit for offset is actually the system page size, rather than 4096 bytes.

       getpagesize(2), mmap(2), mremap(2), msync(2), shm_open(3)

       This page is part of release 3.53 of the Linux man-pages project.  A  description  of  the
       project,     and    information	  about    reporting	bugs,	 can	be    found    at

Linux					    2012-04-16					 MMAP2(2)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 07:29 PM.