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Module: IO
Function: hSeek
Type: Handle -> SeekMode -> Integer -> IO ()
Description:

Computation hSeek hdl mode i sets the position of handle hdl depending on mode. If mode is: 

 * AbsoluteSeek: the position of hdl is 
                 set to i.
 * RelativeSeek: the position of hdl is 
                 set to offset i from the current position.
 * SeekFromEnd:  the position of hdl is set 
                 to offset i from the end of the file.

The offset is given in terms of 8-bit bytes.

Error reporting: the hSeek computation may fail with: isPermissionError if a system resource limit would be exceeded.

Related:

Example 1
File: /tmp/foo.txt : 

Hello, world!
Good bye!

Program source: 

import IO

main = do hdl <- openFile "/tmp/foo.txt" ReadMode
	  a <- hGetChar hdl
	  hSeek hdl AbsoluteSeek 4 
	  b <- hGetChar hdl
	  print (a,b)
	  c <- hGetChar hdl
	  hSeek hdl RelativeSeek 3
	  d <- hGetChar hdl
	  print (c,d)
	  e <- hGetChar hdl
	  hSeek hdl SeekFromEnd (-3)
	  f <- hGetChar hdl
	  print (e,f)

Output: ('H','o')

Output: (',','r')

Output: ('l','y')