expr (1) Linux Manual Page
expr – evaluate expressions Synopsisexpr ,EXPRESSION/ expr ,OPTION/ Description–help display this help and exit –version output version information and exit Print the value of EXPRESSION to standard output. A blank line below separates increasing precedence groups. EXPRESSION may be: ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2 ARG1 & ARG2…
