IT for operating businesses

Using the $ Command

13 January 2026

Expand a Bash variable. More information: <https://gnu.org/software/bash/manual/bash.html#Shell-Variables>.

Print a variable:

echo $*VARIABLE*

Run variable contents as a command:

$*VARIABLE*

Print the PID or the exit status of the previous command:

echo *$!|$?*

Print a random number between 0 and 32767:

echo $RANDOM

Print one of the prompt strings:

echo $*PS0|PS1|PS2|PS3|PS4*

Expand with the output of command and run it. Same as enclosing command in backticks:

$(*command*)

List how many arguments the current context has:

echo $#

Print out a Bash array:

echo $*{array_name[@]*}

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