look at the file tell() and seek() methods. They will tell you the current location and allow you to move to a specific location.
HTH, Alan G Author of the learn to program web tutor http://www.freenetpages.co.uk/hp/alan.gauld ----- Original Message ----- From: "Brian Gustin" <[EMAIL PROTECTED]> To: <tutor@python.org> Sent: Monday, February 20, 2006 12:18 AM Subject: [Tutor] File handling: open a file at specified byte? > HI. This is one I cant seem to find a solid answer on: > > First, some background: > I have a log file that I wrote a python parser for it, and it works > great , but in the interest of saving time and memory , and also to be > able to read the currently active log file, say every 10 minutes , and > update the static file, I was trying to find some way that I can get > python to do this: > > Open log file, read lines up to end of file, and *very important* make a > note of the bytes read, and stash this somewhere (I.E. "mark" the file) , > and then handle the parsing of said file, until all lines have been read > and parsed, write the new files, and close the handler. > say, 10 minutes later, for example, the script would then check the > bytes read , and *very important* start reading the file *from* the > point it marked (I.E. pick up at the point it bookmarked) and read from > that point. > Since the log file will be active (webserver log file) it will have new > data to be read, but I dont want to have to read through the *entire* > log file all over again, just to get to the new data- I want to be able > ot "bookmark" where the log file was read "up to" last time, and then > open the file later at that point. > > My current script works well, but only reads the "day old" log file > (post log rotate) , and it does very well, parsing as much as 3 GB in as > little as 2 minutes if the server isnt heavily loaded when the parser > runs. basically, the webserver runs Tux , which writes a log file for > *all* domains on a server, and the script takes the tux log, and parses > it, extracting the domain for which the log entry is for, and writes a > new line into the domain's apache format CLF log file (this way we are > able to run awstats on individual domains, and get relatively accurate > stats) > > So.. my question is- is there any way to do what I want ? > > Open a live log file, read lines to x bytes, (say 845673231 bytes) , > make a note of this, and 10 miutes later open the same file again *AT* > 845673232 bytes - starting with the next byte after the bookmarked > point, read to end of file, and update the bookmark. > > > Thanks for any pointers- Advice appreciated. > Bri! > > > _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
