#!/bin/bash

## parseline [-n|-e] <LINE> 
## This function must be defined in the sourcing script
##
##  [-n|-e] :  If linefeeder is called with -n every line is passed
##             to parseline with either -n or -e as first parameter
##             -n  Line has a newline
##             -e  Line has no newline


## linefeeder [OPTION] [FILE...]
## Read input line by line and behaves parameter-wise like cat
## 
##  [OPTION]
##      -n   : Provide information to parseline if current line
##             has a newline at the end (parseline -n "$line") 
##             or no newline at the end (parseline -e "$line")
##
##  [FILE]
##      -    : Is treadted as /dev/stdin
##
linefeeder() {
  local newLine=

  for arg in "$@"; do
    case "$1" in 
      -) # treat - as input stream
        break;;
      --) # treat -- as end of parameter
        shift
        break;;
      -n) # Newline detection
        newLine="-n"
        shift;;
      -*) # Ignore other options
        shift;;
    esac
  done

  local file= 
  local line=
  local args=("$@")

  # Use standard input if no files are present
  [ $# -eq 0 ] && args[0]="/dev/stdin"
  
  for file in "${args[@]}"; do
    [ "$file" == "-" ] && file="/dev/stdin"
    newLine=${newLine/"-e"/"-n"}
    while IFS= read -r line; do
      parseline $newLine "$line"
    done <"${file}"
    # If last line in a file has no newline, read ends but still populates $line
    [ -n "$line" ] && parseline ${newLine/"-n"/"-e"} "$line"
  done
}