Conditions in shell script not working

Question

My shell program is:

  testname=methun
  echo "Please enter your name:"
  read username
  if [ "$username" == "$testname"]; then
   age=20
   echo " you are $age years old."
  else
    echo "How old are you?"
    read Age
    if [ "$Age" -le 20]; then
      echo "you are too young."
   else
    if["$Age" -ge 100]; then
      echo " You are old."
    else 
      echo "you are young."
  fi  fi fi

Now when I run my program, it's able to take user input and it shows an error. The error is given below:

./filename line linenumber:sysntax error near unexpected token 'then'
./filename line linenumber: 'if["$username" -eq "$testname"]; then'

Answer 1

You are missing some spaces inside your brackets. It needs to be like this:

if [ "$username" -eq "$testname" ]; then

Then you will realize you have a second problem, which is -eq is for numbers, not strings. So:

if [ "$username" = "$testname" ]; then

Answer 2

You are missing some whitespaces:

#!/bin/bash
testname=methun
echo "Please enter your name:"
read username

if [ "$username" == "$testname" ]; then
  age=20
  echo " you are $age years old."
else
  echo "How old are you?"
  read Age
  if [ "$Age" -le 20 ]; then
    echo "you are too young."
  else
    if [ "$Age" -ge 100 ]; then
      echo " You are old."
    else
      echo "you are young."
    fi
  fi
fi

Answer 3

You need to add a few whitespaces:

if [ "$username" == "$testname" ] ; then
                               ^
                               |
                             here

Or else the string to compare to will be the value of $testname plus an ] . Then the ] will be missing and thus a syntax error.

The same is true for every if in your script.

The space between ] and ; is not strictly needed, but I like it anyway.