llseek(2)

1_llseek(2)                    System Calls Manual                   _llseek(2)
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NAME

6       _llseek - reposition read/write file offset
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #include <sys/syscall.h>      /* Definition of SYS_* constants */
13       #include <unistd.h>
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15       int syscall(SYS__llseek, unsigned int fd, unsigned long offset_high,
16                   unsigned long offset_low, loff_t *result,
17                   unsigned int whence);
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19       Note: glibc provides no wrapper for _llseek(), necessitating the use of
20       syscall(2).
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DESCRIPTION

23       Note:  for  information  about  the  llseek(3)  library  function,  see
24       lseek64(3).
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26       The  _llseek()  system call repositions the offset of the open file de‐
27       scription associated with the file descriptor fd to the value
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29              (offset_high << 32) | offset_low
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31       This new offset is a byte offset relative to the beginning of the file,
32       the  current  file offset, or the end of the file, depending on whether
33       whence is SEEK_SET, SEEK_CUR, or SEEK_END, respectively.
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35       The new file offset is returned in  the  argument  result.   The   type
36       loff_t is a 64-bit signed type.
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38       This  system call exists on various 32-bit platforms to support seeking
39       to large file offsets.
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RETURN VALUE

42       Upon successful completion, _llseek() returns 0.  Otherwise, a value of
43       -1 is returned and errno is set to indicate the error.
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ERRORS

46       EBADF  fd is not an open file descriptor.
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48       EFAULT Problem with copying results to user space.
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50       EINVAL whence is invalid.
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VERSIONS

53       You probably want to use the lseek(2) wrapper function instead.
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STANDARDS

56       Linux.
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