1LLSEEK(2) Linux Programmer's Manual LLSEEK(2)
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6 _llseek - reposition read/write file offset
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9 #include <sys/syscall.h> /* Definition of SYS_* constants */
10 #include <unistd.h>
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12 int syscall(SYS__llseek, unsigned int fd, unsigned long offset_high,
13 unsigned long offset_low, loff_t *result,
14 unsigned int whence);
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16 Note: glibc provides no wrapper for _llseek(), necessitating the use of
17 syscall(2).
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20 Note: for information about the llseek(3) library function, see
21 lseek64(3).
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23 The _llseek() system call repositions the offset of the open file de‐
24 scription associated with the file descriptor fd to the value
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26 (offset_high << 32) | offset_low
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28 This new offset is a byte offset relative to the beginning of the file,
29 the current file offset, or the end of the file, depending on whether
30 whence is SEEK_SET, SEEK_CUR, or SEEK_END, respectively.
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32 The new file offset is returned in the argument result. The type
33 loff_t is a 64-bit signed type.
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35 This system call exists on various 32-bit platforms to support seeking
36 to large file offsets.
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39 Upon successful completion, _llseek() returns 0. Otherwise, a value of
40 -1 is returned and errno is set to indicate the error.
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43 EBADF fd is not an open file descriptor.
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45 EFAULT Problem with copying results to user space.
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47 EINVAL whence is invalid.
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50 This function is Linux-specific, and should not be used in programs in‐
51 tended to be portable.
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54 You probably want to use the lseek(2) wrapper function instead.
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57 lseek(2), open(2), lseek64(3)
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60 This page is part of release 5.13 of the Linux man-pages project. A
61 description of the project, information about reporting bugs, and the
62 latest version of this page, can be found at
63 https://www.kernel.org/doc/man-pages/.
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67Linux 2021-03-22 LLSEEK(2)