UGU: Unix Guru Universe - Unix Tip #4350- February 7, 2014
- Home : Help
: Today's Tip
Unix Tip #4350- February 7, 2014
THE BAD AND THE GOOD
I cringe anytime I see someone code inefficiently. Here are
three of the most common mistakes, followed by a better way to
do the same thing.
Bad: cat somefile | grep something
Better: grep something somefile
Why: You're running one program (grep) instead of two (cat
Bad: ps -ef | grep something | grep -v grep
Better: ps -ef | grep [s]omething
Why: You’re running two commands (grep) instead of three (ps
and two greps).
Bad: cat /dev/null > somefile
Better: > somefile
Why: You're running a command (cat) with I/O redirection,
instead of just redirection.
Although the bad way will have the same result, the good way is
far faster. This may seem trivial, but the benefits will really
show when dealing with large files or loops.
This tip generously supported by: email@example.com
NOTE: All tips provided are USE AT YOUR OWN RISK. Tips are submitted
by various unix admins around the globe. UGU suggest you read and
test each tip in a non-volitile environment before placing into
LAST 5 TIPS
- SUSPEND A VI SESSION FOR SHELL
- BC AND NOT BEFORE AD
- LISTING FILES BY SIZE
- WHERE AM I ALWAYS
- WHO SENT ME MAIL
I want to
and get a UGU Tip everyday.
I want to
and NOT get a UGU Tip everyday.
If you have a UNIX TIP let us know, we just may use it:
(All tips become the property of the Unix Guru Universe)
Copyright 1994-2011 Unix Guru Universe