Manipulating text files

Word count
 [root]# wc readme.txt
 [root]# wc -l readme.txt  --> number of lines
 [root]# wc -w readme.txt  --> number of words

Command substitution
 [root]# rm `cat garbage-files.list.txt` 

Combining commands
 [root]# cp file1 file2; rm file3 
 [root]# grep Austin cities.txt && vi cities.txt
                                      ---------- 
                                           |_ executes vi if grep succeeds
 
 [root]# grep Florida states.txt || grep Missisipi states.txt
 [root]# grep -E '^abc$ ^def$'
 [root]# grep -F -x 'abc def'
 [root]# find joomla/ -type f -print0 | xargs -0 grep "font" 

 [root]# dmesg | grep ^Blue*
 [root]# ifconfig -a | more
 [root]# grep -c '^processor' /proc/cpuinfo
 [root]# grep -i 'orange' /proc/cpuinfo  ---------------------> ignore case
 [root]# grep -B 0 -A 1 --color '^bind' /etc/redis.conf ------> show lines before and after

Grep only uncommented line of configuration
 [root@thermalite ~]# cat /var/lib/pgsql/data/postgresql.conf | awk '{$1=$1;print}' | grep -v "^#" | awk 'NF'