Equivalent of __FILE__ and __LINE__ in Bash

Question

Is there any variable in bash that contains the name of the .sh file executed? The line number would be great too.

I want to use it in error messages such as:

<

Answer 1

Here's how to do it in a reusable function. if the following is in a file named script:

#!/bin/bash
debug() {
  echo "${BASH_SOURCE[1]##*/}:${FUNCNAME[1]}[${BASH_LINENO[0]}]" > /dev/tty
}
debug

This produces the output:

script:main[5]    

Which indicates the line on which debug was called.

---

The following will print out the filename, function, line and an optional message.

Also works in zsh for extra goodness.

# Say the file, line number and optional message for debugging
# Inspired by bash's `caller` builtin
# Thanks to https://unix.stackexchange.com/a/453153/143394
function yelp () {
  # shellcheck disable=SC2154  # undeclared zsh variables in bash
  if [[ $BASH_VERSION ]]; then
    local file=${BASH_SOURCE[1]##*/} func=${FUNCNAME[1]} line=${BASH_LINENO[0]}
  else  # zsh
    emulate -L zsh  # because we may be sourced by zsh `emulate bash -c`
    # $funcfiletrace has format:  file:line
    local file=${funcfiletrace[1]%:*} line=${funcfiletrace[1]##*:}
    local func=${funcstack[2]}
    [[ $func =~ / ]] && func=source  # $func may be filename. Use bash behaviour
  fi
  echo "${file##*/}:$func:$line $*" > /dev/tty
}