use-case

let say there is one long command you often use, may be ssh to server with certificate ip and user

so either you go from history to connect or you type every time.

for history, that may be clean some time or you working on multiple terminal window at once and close them.

so what is the good alternative?

use alias , type once, and use every time from anywhere

like

1) command : /usr/bin/php7.0 -d memory_limit=-1 /var/www/html/bin/phar/php7cc.phar

either I type every time this command or can make an alias like

>>> /usr/bin/php7.0 -d memory_limit=-1 /var/www/html/bin/phar/php7cc.phar

make an entry in ~/.bash_aliases

alias php7cc='/usr/bin/php7.0 -d memory_limit=-1 /var/www/html/bin/phar/php7cc.phar'

reload it with

>>> source ~/.bashrc

now i just need to type php7cc inn command prompt to run this whole command

>>> php7cc

if [ -f ~/.bash_aliases ]; then
. ~/.bash_aliases
fi

2)     alias sdu=’du -hs * | sort -hr’