Python Tutorial ( PDFDrive )

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!!
os.ftruncate(fd, length)
Description
The method ftruncate() truncates the file corresponding to file descriptor fd, so that it is at most length bytes in
size.
Syntax
Following is the syntax for ftruncate() method:
os.ftruncate(fd, length)
Parameters
• fd -- This is the file descriptor, which needs to be truncated.
• length -- This is the length of the file where file needs to be truncated.
Return Value
This method does not return any value.
Example
The following example shows the usage of ftruncate() method.
#!/usr/bin/python
import os, sys
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