Shorten "ERROR line $LINENO: ..."

leniviy · 10-02-2012, 07:07 AM

Hi. Does anyone know a way to shorten the error message prefix with the $LINENO variable in shell scripts?

I would like to have

Code:

$fatal "FILE not specified"

instead of

Code:

    echo "ERROR line $LINENO: FILE not specified" >&2
    exit 1

But to expand $LINENO one needs to use 'eval' and I don't want to pass the other arguments to eval:

Code:

_fatal() {
  ... "$@"
}
fatal='eval _fatal $LINENO'

ntubski · 10-02-2012, 08:38 AM

If you are using bash, BASH_LINENO gives you an array of all the line numbers in the call stack:

Code:

fatal() {
  echo "ERROR line ${BASH_LINENO[0]}: $@" >&2
  exit 1
}

David the H. · 10-04-2012, 08:49 AM

I'm not following the request here. Why do you need to use eval? Why doesn't $LINENO expand on its own?

Is it because you're trying to call the function this way?

Code:

fatal='eval _fatal $LINENO'

Shouldn't you be using this instead?

Code:

fatal=$( _fatal "$LINENO" )

...which captures the stdout of the _fatal function into the variable $fatal.

How about giving us some more context, and the actual contents of the function, so we can more easily know what you're trying to do?

(As an additional point, having both a variable and a function with almost the same name is rather confusing. )

leniviy · 10-05-2012, 01:24 AM

Quote:

Originally Posted by ntubski

If you are using bash, BASH_LINENO gives you an array of all the line numbers in the call stack:

Code:

fatal() {
  echo "ERROR line ${BASH_LINENO[0]}: $@" >&2
  exit 1
}

Thanks