Handy for debugging and watching what's going on while it's going on. Use tail with the “f” option, which lets you read the end of a growing file. Examples:
$ tail -f /var/log/messages$ tail -f /var/log/syslog $ tail -f /var/log/mail.log $ tail -f /usr/local/httpd/logs/error_log
Need to capture some output to a terminal that can't be redirected easily to a file with “>”? Use script. At a command prompt type script, then do what ever you need to log and exit. The log of _ALL_ the stuff sent to your terminal finds its way into a file called typescript! Example:
tux@coollinuxbox:/home/tux$ scriptscript: WARNING: script session is not secure against eavesdropping/hijacking! script: read /usr/doc/bsdutils/README.script for details. Script started, output file is typescript tux@coollinuxbox:/home/tux$ python python commands control-D tux@coollinuxbox:/home/tux$ exit Script done, output file is typescript tux@coollinuxbox:/home/tux$ cat typescript Script started on Thu Oct 12 12:03:22 2000 tux@coollinuxbox:/home/tux$ python Python 1.5.2 (#1, Dec 15 1999, 11:15:06) [GCC 188.8.131.52] on linux2 Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam >>> 45+89+12.25+63.21 209.46 >>> 70/12 5 >>> 70%12 10 >>> tux@coollinuxbox:/home/tux$ exit Script done on Thu Oct 12 12:04:43 2000 tux@coollinuxbox:/home/tux$
Wanna make a clone of one hardisk to another? Use tar. Hook up your soon-to-be-cloned hardisk to your system (power off during this operation). Boot your box. As root, cd to /. Mount the new hard drive on /mnt. Then run the following command:
$ tar clf - . | ( umask 0; cd /mnt; tar xvf - )
c = createl = stay on local filesystem (don't cross filesystem boundaries)f = file (the next argument is the name of the tarfile or “-”)- = write to standard out or read from standard inx = extractv = verbose
“umask 0” ensures that the new files have the same permissions as the old ones.
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