Tutorials Point


  Python Basics
  Python Advanced
  Python Useful References
  Python Useful Resources
  Selected Reading

© 2011 TutorialsPoint.COM


  Home     References     Discussion Forums     About TP  

Python os.lseek() Method


previous next AddThis Social Bookmark Button


Description:

This method sets the current position of file descriptor fd to the given position pos, modified by how as explained below.

Syntax:

os.lseek(fd, pos, how)

Parameters:

Here is the detail of parameters:

  • fd: This is the file descriptor which needs to be processed.

  • pos: This is the position in the file with respect to given parameter how. You give os.SEEK_SET or 0 to set the position relative to the beginning of the file, os.SEEK_CUR or 1 to set it relative to the current position; os.SEEK_END or 2 to set it relative to the end of the file.

  • fd: This is the reference point with-in the file. os.SEEK_SET or 0 means beginning of the file, os.SEEK_CUR or 1 means the current position and os.SEEK_END or 2 means end of the file.

Example:

#!/usr/bin/python

import os, sys

# Open a file
fd = os.open( "foo.txt", os.O_RDWR|os.O_CREAT )

# Write one string
os.write(fd, "This is test")

# Now you can use fsync() method.
# Infact here you would not be able to see its effect.
os.fsync(fd)

# Now read this file from the beginning
os.lseek(fd, 0, 0)
str = os.read(fd, 100)
print "Read String is : ", str

# Close opened file
os.close( fd )

print "Closed the file successfully!!"

This would produce following result:

Read String is :  This is test
Closed the file successfully!!


previous next Printer Friendly



  

Advertisement

Online Image Processing

Indian Baby Names