dc:tldr:61f90

The command "dc" is a reverse-polish notation calculator used in Unix-like systems. It evaluates mathematical expressions by operating on a stack.

In the given command: dc --expression='${10} k ${5 3 -} p'

• dc: It is the command that invokes the reverse-polish notation calculator.
• --expression=: It specifies that the following argument will be the expression to be evaluated.
• ${10}: It pushes the value 10 onto the stack.
• k: It duplicates the value at the top of the stack.
• ${5 3 -}: It subtracts 3 from 5 and pushes the result (2) onto the stack.
• p: It pops the top value from the stack and prints it.

So, the command, when executed, will push the value 10 on the stack, duplicate it, subtract 3 from 5, and finally print the result (2).