Question: I have a simple bash script:

```
#!/bin/bash

counter=0
while [ $counter < 100 ]; do
   echo $counter
   counter=$((counter+1))
done

```

However, when I try to execute this, I get this error:

```
./test: line 4: 100: No such file or directory

```

Answer: 
In bash, `<` redirects standard input, so you're telling bash to read from the file called `100`, which doesn't exist. Instead use `-lt` for comparing numbers.

```
#!/bin/bash

counter=0
while [ $counter -lt 100 ]; do
   echo $counter
   counter=$((counter+1))
done

```

Does what you want.
The "less than" operator is `-lt`, not `<`.

`<` will redirect the file contents to the command on the left. That's why you have this error: the file `100` does not exist.