tail -f in python with no time.sleep

Question

I need to emulate "tail -f" in python, but I don't want to use time.sleep in the reading loop. I want something more elegant like some kind of blocking read, or select.select with timeout, but python 2.6 "select" documentation specifically says: "it cannot be used on regular files to determine whether a file has grown since it was last read." Any other way? In a few days if no solution is given I will read tail's C source code to try to figure it out. I hope they don't use sleep, hehe Thanks.

MarioR

Answer 1

(update) Either use FS monitors tools

• For linux
• For Windows
• For Mac

Or a single sleep usage (which I would you consider as much more elegant).

import time
def follow(thefile):
    thefile.seek(0,2)      # Go to the end of the file
    while True:
         line = thefile.readline()
         if not line:
             time.sleep(0.1)    # Sleep briefly
             continue
         yield line

logfile = open("access-log")
loglines = follow(logfile)
for line in loglines:
    print line