Find a line in a header of an IMG file

Hi

I have these IMG files (an example is attached resaved as a txt) where I'm looking to extract specific lines (namely the 38th line, PLANET_DAY_NUMBER = [value]) from many of these files.

I would like to start out by making a code that finds the specified value in a given IMG file and outputs it (so basically grabbing the value of planet day number and showing me what that number is). I can figure out how to expand upon this basic idea so I can apply the code to a batch of files, but I'm not sure what to use to grab the string I want in the first place.

Can anyone help?

Also, I will give any clarification necessary, this might not have been super clear.

Answer 1

[Walter Roberson]

filestring = fileread('1n128464653ffl0200p1516l0m1.txt');
pdn = regexp(filestring, '^(?<=PLANET_DAY_NUMBER\s*=\s*).*$', 'match', 'lineanchors', 'dotexceptnewline');