Super Specific UNIX Commands + Other Stuff

echo -n

will cause the command not to output a trailing line

echo -e

enable interpretation of backslash escapes

\a

bell

\b

backspace

\c

prevents a new line following the command

\f

form feed

\n

new line

\r

carriage return

\t

horizontal tab

\v

vertical tab

HOME

home dir

PS1

string used as prompt sign

PS2

prompt sign when [return] is pressed

CDPATH

abs pathnames - affects cd command

SHELL

pathname of bash

TERM

terminal type

TZ

time zone

cat -n

number all output lines

cat -A

display non printing chars

cat -b

number output lines skipping empty lines

wc -w

word count

wc -l

line count

cut -c

print chars by position

cut -d

print chars by delimiter

ps -a

displays the status of all active processes

ps -f

displays a full list of info

grep -c

count matching lines

grep -i

ignore case

grep -l

Displays list of a filenames only.

grep -n

include line number in output

grep -v

displays non-matching lines.

sort -b

ignore leading blanks

sort -d

sorts in alphanumeric or dictionary order

sort -f

ignore case

sort -n

sort numerically

sort -o

writes results to file specified

sort -r

sort in reverse order

shell script: $0

name of script

shell script: $1 ... $9

parameters 1 through parameters 9

shell script: $#

number of parameters

shell script: $@

all parameters

shell script: $?

exit status of prev command

shell script: $*

all parameters

shell script: $$

contains PID (process id)

testing files: test -r fileName

fileName exist and readable?

testing files: test -w fileName

fileName exist and writable?

testing files: test -s fileName

fileName exist and nonzero length?

testing files: test -f fileName

fileName exist and not dir?

testing files: test -d fileName

fileName exist and is dir?

sh -n

reads commands of a shell script but doesn't execute

sh -v

displays the lines of code while executing a shell script

sh -x

displays the command and arguments as a shell script is run

ps -a

displays the status of all active processes