Bash for manipulating curly bracket delimited config files [closed] - regex

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Currently I have a config file of the following form:
under Time {
TimeStep = 0.001;
MaxTime = 0.2;
MaxIts = 400;
Type = Implicit;
under Implicit {
Type = ForwardEuler;
Jacobian = FiniteDifference;
under Newton {
MaxIts = 20;
Eps = 0.01;
}
}
}
First Question: I want to write a set of bash scripts that can
set property = value in a file; add it if it is not there.
get property from such a file.
line-by-line editting is not suitable here: take MaxIts for example, the script needs to distinguish between Time.MaxIts and Time.Implicit.MaxIts.
Second Question: I want to write a bash script that transforms above into:
Time.TimeStep = 0.001;
Time.MaxTime = 0.2;
Time.MaxIts = 400;
Time.Type = Implicit;
Time.Implicit.Type = ForwardEuler;
Time.Implicit.Jacobian = FiniteDifference;
Time.Implicit.Newton.MaxIts = 20;
Time.Implicit.Newton.Eps = 0.01;
so that sed or awk can do the job simply.

Answer 1

Here's how to do the 2nd part:
$ cat tst.awk
function descend(name) {
while ( (getline > 0) && !/}/ ) {
if ( /{/ ) {
descend(name "." $2)
}
else {
sub(/^[[:space:]]+/,"")
print name "." $0
}
}
}
{ descend($2) }
$ awk -f tst.awk file
Time.TimeStep = 0.001;
Time.MaxTime = 0.2;
Time.MaxIts = 400;
Time.Type = Implicit;
Time.Implicit.Type = ForwardEuler;
Time.Implicit.Jacobian = FiniteDifference;
Time.Implicit.Newton.MaxIts = 20;
Time.Implicit.Newton.Eps = 0.01;
I'm sure you can write a script to do the reverse mapping and then you can just do all the manipulation related to your first question on the flat format above.