readBytes

readBytes(fileHandle, sizeInByte)

fileHandle is the handle of the file to read.

sizeInByte is an integer indicating the number of bytes to read.

Read the given number of bytes from the handle. If the file reaches the end or an IO error occurs, an IOException will be raised; otherwise a buffer containing the given number of bytes will return. We must know the exact number of bytes to read before calling this function.

This example defines a function to copy a file:

def fileCopy(source, target){
s = file(source)
len = s.seek(0,TAIL)
s.seek(0,HEAD)
t = file(target,"w")
if(len==0) return
do{
  buf = s.readBytes(min(len,1024))
  t.writeBytes(buf)
  len -= buf.size()
}while(len)
};
fileCopy("test.txt","testcopy.txt");