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mmap2() - Unix, Linux System Call


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NAME

mmap2 - map files or devices into memory

SYNOPSIS

#include <sys/mman.h> 

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

DESCRIPTION

The mmap2() system call operates in exactly the same way as mmap(2), except that the final argument specifies the offset into the file in 4kB units (instead of bytes). This enables applications that use a 32-bit off_t to map larger files (typically up to 2^44 bytes).

RETURN VALUE

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

ERRORS

TagDescription
EFAULT Problem with getting the data from userspace.

CONFORMING TO

This system call is Linux specific.

NOTES

Glibc does not provide a wrapper for this system call; call it using syscall(2).

mmap2() is available since Linux 2.3.31. It is Linux specific, and should be avoided in portable applications. On 32-bit systems, mmap2() is used to implement the mmap64() function that is part of the LFS (Large File Summit).

SEE ALSO



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