Some cool one liners..

sum numbers in first column of a file
$ cat filename | awk 'BEGIN { tot=0 } { tot+=$1 } END { print tot }'

only print certain lines in a file, eq 20 - 30
$ sed -n -e 20,30p filename

Search all files in and below for a string xyz:
$ find . -exec egrep xyz {} \; -print

Remove all files name ".log.tmp"
$ find . -name .log.tmp -exec rm {} \;

search a file for any of three strings:
$ egrep 'abc|xyz|or' filename

ELIMINATING MULTIPLE SPACES

Here is a simple script whichhelps in eliminating multiplespaces when one wants toextract a particular columnin a set of records from afile.

Here is an example to provethe same:

ps -u $LOGNAME tr -s " " : cut -d: -f

The above script line can beused to extract a column fromthe output of a ps command for a particular user ($LOGNAME).