Sets the starting position for the next xzread or xzwrite on the given compressed file. The offset represents a number of bytes in the uncompressed data stream. The whence parameter is defined as in lseek(2); the value SEEK_END is not supported.
If the file is opened for reading, this function is emulated but can be extremely slow. If the file is opened for writing, only forward seeks are supported; xzseek then compresses a sequence of zeroes up to the new starting position.
xzseek returns the resulting offset location as measured in bytes from the beginning of the uncompressed stream, or -1 in case of error, in particular if the file is opened for writing and the new starting position would be before the current position.
|
|
file/in "gz" filehandle from xzopen. |
|
|
offset |
|
|
whence |
|
|
Result |
|
|
file/out |
