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