Needed to do this and after a bit of looking around (Bash scripting) came up with this:
#!/bin/bash FILE_LIST_SOURCE=listoffiles.txt DEFAULT_FILE="some.default.file" [ -f $FILE_LIST_SOURCE ] && LIST_OF_FILES=$(cat $FILE_LIST_SOURCE) LIST_OF_FILES=${LIST_OF_FILES:-$DEFAULT_FILE} #echo -e "\\nLIST_OF_FILES:\\n$LIST_OF_FILES" echo "List of files:" for i in $LIST_OF_FILES; do echo $i done