LSEEK.2
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- LSEEK(2) Minix Programmer's Manual LSEEK(2)
- NAME
- lseek - move read/write pointer
- SYNOPSIS
- #include <sys/types.h>
- #include <unistd.h>
- #define SEEK_SET 0 /* offset is absolute */
- #define SEEK_CUR 1 /* relative to current position */
- #define SEEK_END 2 /* relative to end of file */
- off_t lseek(int d, off_t offset, int whence)
- DESCRIPTION
- The descriptor d refers to a file or device open for reading and/or
- writing. Lseek sets the file pointer of d as follows:
- If whence is SEEK_SET, the pointer is set to offset bytes.
- If whence is SEEK_CUR, the pointer is set to its current location
- plus offset.
- If whence is SEEK_END, the pointer is set to the size of the file
- plus offset.
- Upon successful completion, the resulting pointer location as measured in
- bytes from beginning of the file is returned. Some devices are incapable
- of seeking. The value of the pointer associated with such a device is
- undefined.
- NOTES
- Seeking far beyond the end of a file, then writing, creates a gap or
- "hole", which occupies no physical space and reads as zeros.
- RETURN VALUE
- Upon successful completion, the current file pointer value is returned.
- Otherwise, a value of -1 is returned and errno is set to indicate the
- error.
- ERRORS
- Lseek will fail and the file pointer will remain unchanged if:
- [EBADF] Fildes is not an open file descriptor.
- [ESPIPE] Fildes is associated with a pipe or a socket.
- [EINVAL] Whence is not a proper value.
- 4BSD February 24, 1986 1
-
- LSEEK(2) Minix Programmer's Manual LSEEK(2)
- SEE ALSO
- fcntl(2), open(2).
- BUGS
- This document's use of whence is incorrect English, but maintained for
- historical reasons.
- 4BSD February 24, 1986 2
English
