How to read required information from particular line

Hi, I want to read from particular line as follows:

From the text file I want to read after the below line:

Additional information:
Alarm:100567
system error alarm:5480

I want to save information above the line where it appears 5480. The line above this is "Alarm:100567" Finally I want to note 100567 in my output.

Please help me how to do this. (I tried with strtok, but not successes).

Many thanks in advance

Answer 1

[Azzi Abdelmalek]

fid=fopen('file.txt')
a=fgetl(fid)
k=0
while ischar(a)
  k=k+1
  r{k,1}=a
  a=fgetl(fid)
end
fclose(fid)
id=find(~cellfun(@isempty,regexp(r,'5480')))
c=regexp(r(id-1),'\d+','match')
out=str2double(c{1})

If this repeats in your file

id=find(~cellfun(@isempty,regexp(r,'5480')))
for k=1:numel(id)
  c=regexp(r(id(k)-1),'\d+','match')
  out(k)=str2double(c{1})
end