remove all carriage returns

cat file | tr -d '\n'

url encoding and decoding

echo 'http://example.com' | nkf -WwMQ | sed 's/=$//g' | tr = % | tr -d '\n'

echo http%3A%2F%2Fexample%2Ecom | nkf -w --url-input

handle files which name may include spaces

find dirname -print0 | xargs -0 ls

convert character code from sjis to UTF8

iconv -f SJIS -t UTF8 oldfile > newfile

set positional parameter

$ set -a -b foo bar
$ echo $# $@
2 foo bar

$ set -- -a -b foo bar
$ echo $# $@
4 -a -b foo bar

w | awk '$1~/'$(whoami)'/{print}' | while read line; do
  set ${line}; echo USER:$1 TTY:$2 FROM:$3 LOGIN@:$4 IDLE:$5 JCPU:$6 PCPU:$7 WHAT:${*:8}
done

color text

esc=$(printf '\033')

color="${esc}[36m" # cyan
bold="${esc}[1m"
underline="${esc}[4m"
colorbold="${esc}[1;36m"
colorunderline="${esc}[4;36m"
reset="${esc}[0m"

echo "${color}color text${reset}"
echo "${bold}bold text${reset}"
echo "${underline}underline text${reset}"
echo "${colorbold}color bold text${reset}"
echo "${colorunderline}color underline text${reset}"
echo normal text