LSEEK(S) XENIX System V LSEEK(S)
Name
lseek - Moves read/write file pointer.
Syntax
long lseek (fildes, offset, whence)
int fildes;
long offset;
int whence;
Description
fildes is a file descriptor returned from a creat, open,
dup, or fcntl system call. lseek sets the file pointer
associated with fildes as follows:
If whence is 0, the pointer is set to offset bytes.
If whence is 1, the pointer is set to its current location
plus offset.
If whence is 2, the pointer is set to the size of the file
plus offset.
Upon successful completion, the resulting pointer location
as measured in bytes from the beginning of the file is
returned.
lseek will fail and the file pointer will remain unchanged
if one or more of the following are true:
fildes is not an open file descriptor. [EBADF]
fildes is associated with a pipe or fifo. [ESPIPE]
whence is not 0, 1 or 2. [EINVAL and SIGSYS signal]
The resulting file pointer would be negative. [EINVAL]
Some devices are incapable of seeking. The value of the
file pointer associated with such a device is undefined.
Return Value
Upon successful completion, a nonnegative integer indicating
the file pointer value is returned. Otherwise, a value of
-1 is returned and errno is set to indicate the error.
See Also
creat(S), dup(S), fcntl(S), open(S)
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