I have a text file named t1.txt, it contains:300400500600Now I want to find how many numbers in this text are less than 450And I give the following code:b=0for i in $(cat t1.txt)do  if [$i -lt 450]  then    ((b=b+1))  fidoneecho bbut it doesn't work.What should I do?Thank you.
how can I do calculation of numbers from text file in shell script
linux;bash;shell script;shell