script to edit config files - bash

Question

I'm working on a script that would allow me to add, remove, or edit config files. I have tested it a little and it seems like I got it to work at least with a single file, but I would like to be able to just do .config or fi.config and have it perform the desired action.
I would appreciate any help.
Config file looks looks similar to this just bigger
-- Config File
-- Environment DEV7
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
-- General properties
-------------------------------------------------------------------------------
com.x.yy.zz.version=2.0.2
com.x.yy.zz.instanceRole.ServerA=PRIMARY
com.x.yy.zz.instanceRole.ServerB=SECONDARY
com.x.yy.zz.StopDelay=30
com.x.yy.zz.sourceType=t
com.x.yy.zz.sNumberInc=20000
com.x.yy.zz.sNumberMin=20000
com.x.yy.zz.sNumberMax=9980000
so -a would allow me to add a line after something
ex. -a StopDealy New
com.x.yy.zz.StopDelay=30
New
#!/bin/bash
i=1
usage()
{
echo "test usage"
}
if [[ $# -gt 4 ]]
then
i=2
fi
while [[ $# -gt $i ]]
do
key="$1"
case $key in
-f|--file)
file="$2"
shift
;;
-a|--after)
sed -i "/$2/a $3" $file
#shift # past argument
;;
-b|--before)
sed -i "/$2/i $3" $file
#shift
;;
-d|--delete)
sed -i "/$2/d" $file
#shift
;;
-e|--edit)
sed -ie "s/$2/$3/g" $file
shift
;;
*)
usage
;;
esac
shift # past argument or value
done

Answer 1

I didn't test it yet, but this is the closest version to what I understand you want to achieve.
#!/bin/bash
usage() {
echo "Usage: $0 -f file1 -f *.txt -[abde] ... -f file3 ... -[abde] ... "
}
# Do all the required action on one file
do_work() {
file="$1" # 1st argument must be the file to work on
shift
while [[ $# -gt 0 ]]; do
case "$1" in
-f|--file) while [[ ! "$2" = -* && $# -gt 0 ]]; do shift; done ;; # Ignore any "file" since we have one to work on.
-a|--after) sed -i "/$2/a $3" $file; shift 2 ;;
-b|--before) sed -i "/$2/i $3" $file; shift 2 ;;
-d|--delete) sed -i "/$2/d" $file; shift ;;
-e|--edit) sed -ie "s/$2/$3/g" $file; shift 2 ;;
esac
shift # past argument or value
done
}
# Check the arguments for files and print the valid ones
# Other arguments will just be skipped
# Invalid arguments will be displayed.
identify_files() {
while [[ $# -gt 0 ]]; do
case "$1" in
-f|--file) # Validate the the file exists (just in case)
# check each following argument until next option
# ... or end of arguments
while [[ ! "$2" = -* && $# -gt 0 ]]; do
if [[ -f "$2" ]]; then
echo "$2"
else
echo "Error: Invalid file '$2'." >&2
fi
shift
done ;;
-[abe]) shift 2 ;;
-d) shift ;;
-h) usage >&2; exit ;;
*) echo "Invalid otpion '$1'" >&2 ;;
esac
shift
done
}
# Do the required actions on all files received in the options
for File in $(identify_files "$#"); do
do_work "$File" "$#"
done
## Alternative on predefined files (not the ones received as arguments)
## Usage: $0 -[abde] ...
#for File in $(ls *.config); do
# do_work "$File" "$#"
#done