Python os.lseek() Method
The method lseek() sets the current position of file descriptor fd to the given position pos, modified by how.
Following is the syntax for lseek() method
os.lseek(fd, pos, how)
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.
how -- 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.
This method does not return any value.
The following example shows the usage of lseek() method.
#!/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!!"
Let us compile and run the above program, this will produce the following result:
Read String is : This is test Closed the file successfully!!