1_llseek(2) System Calls Manual _llseek(2)
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6 _llseek - reposition read/write file offset
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9 Standard C library (libc, -lc)
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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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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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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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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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53 You probably want to use the lseek(2) wrapper function instead.
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56 Linux.
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59 lseek(2), open(2), lseek64(3)
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63Linux man-pages 6.04 2023-03-30 _llseek(2)