Misc Substitution

$(command) replace with the standard output of command
$((arithmetic-expression) replace with the result of arithmetic-expression
$(<file) replace with the contents of file
`command ` replace with the standard output of command
replace with $HOME
user replace with the home directory of user
∼– replace with $OLDPWD (previous directory)
∼+ replace with $PWD (current directory)

Get Korn Shell: Unix and Linux Programming Manual, Third Edition, The now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.