man2/mmap2.2

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  25 .\" Modified 31 Jan 2002, Michael Kerrisk <mtk-manpages@gmx.net>
  26 .\"     Added description of mmap2
  27 .\" Modified, 2004-11-25, mtk -- removed stray #endif in prototype
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  29 .TH MMAP2 2 2002-01-31 "Linux 2.3.31" "Linux Programmer's Manual"
  30 .SH NAME
  31 mmap2 \- map files or devices into memory
  32 .SH SYNOPSIS
  33 .B #include <sys/mman.h>
  34 .br
  35 .B #include <syscall.h>
  36 .br
  37 .B #include <errno.h>
  38 .sp
  39 .BI "_syscall6(void *, " mmap2 ", void *, " start ", size_t, " length ,
  40 .BI "int, " prot ", int, " flags ", int, " fd ", off_t, " pgoffset )
  41 .sp
  42 .BI "void * mmap2(void *" start ", size_t " length ", int " prot ,
  43 .BI "int " flags ", int " fd ", off_t " pgoffset );
  44 .SH DESCRIPTION
  45 The function
  46 .B mmap2
  47 operates in exactly the same way as
  48 .BR mmap (2),
  49 except that the final argument specifies the offset into the
  50 file in units of the system page size (instead of bytes).
  51 This enables applications that use a 32-bit
  52 . I off_t
  53 to map
  54 larger files (typically up to 2^44 bytes).
  55 .SH "RETURN VALUE"
  56 On success,
  57 .B mmap2
  58 returns a pointer to the mapped area. On error \-1 is returned
  59 and
  60 .I errno
  61 is set appropriately.
  62 .SH ERRORS
  63 .TP
  64 .SH EFAULT
  65 Problem with getting the
  66 data from userspace.
  67 .SH NOTES
  68 The function
  69 .B mmap2
  70 is available since Linux 2.3.31.
  71 It is Linux specific, and should be avoided in portable applications.
  72 See also the
  73 .I mmap64()
  74 function that is part of the LFS (Large File Summit).
  75 .SH "SEE ALSO"
  76 .BR getpagesize (2),
  77 .BR mmap (2),
  78 .BR mremap (2),
  79 .BR msync (2),
  80 .BR shm_open (2)