The $( ) notation is a modern replacement for the ` ` (also called the "backtick") notation, both submit the contents to a subshell for execution and replace it with the output of that command. For example:
echo Today is $(date)
would produce the actual date in the string. Make sense? That’s what should be happening above.
The notation then translates step by step:
test $value < $(echo $string | wc -c)
then has the echo $string | wc -c replaced with the number of characters in the variable "string". That's going to be 15, so now we're testing:
test $value < 15
since the variable "value" has been set to 3, we're really testing
test 3 < 15
which should certainly be true!
I notice two additional things in your example, though. First, you have /bin/sh/ with the trailing slash, which might be a problem. But you also might not be finding that you have Bash as your default shell on your system too, so do you want to try
#!/bin/bash
and see if that works.
Let me know how it goes!
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please let me know ,we type script in editor, i am using vi editor after that at command line we type :wq save and quit enter, we'll go to $ prompt then how to to see output for perticular script? is it shell dependent if yes let me know for borne,c-shell.please