#!/bin/bashusage () {echo run with 1st argument       -mux2 or mux4 or mux8 or default(mux2) or all ( all the 3 mux) echo 2nd argument       -struct or ifs or cases or asgn or default(struct) or all(all the        conditions)echo 3rd argument     -on (waveform) or off (no wave) or default(off)'echo run       - should take mux2 struct off as arguments}if [ $1 == mux2 -o $1 == mux4 -o $1 == mux8 ]; thenif [ $2 == struct -o $2 == ifs -o $2 == cases -o $2==asgn ]; then  if [ $3 == on ]; then  iverilog -o mux $1.v  $1TB.v -D $2   vvp mux  gtkwave T.vcd  elif [ $3 == off -o $3 ==  ]; then  iverilog -o mux $1.v  $1TB.v -D $2   vvp mux  else  usage  fi elif [ $2 == all ]; then $0 $1 struct $3 $0 $1 ifs $3 $0 $1 cases $3 $0 $1 asgn $3 elif [ $2 == ]; then $0 $2 struct $3 else usage fielif [ $1 == all ]; then$0 mux2 $2 $3$0 mux4 $2 $3$0 mux8 $2 $3elif [ $1 ==  ]; then$0 mux2 stuctelseusagefiThe usage is displaying more than once when I run script with the following arguments:run all jhjjkrun all all kjkjHow can I make usage to print only once?
How can i make usage to print only once
shell script