How i use a variable name to do a fid=fopen?

Hi,

I execute a program in this way program('Untitled')

and i wan't that

if exist ('file','var')
    input_file = ('Untitled.inp');
    fid = fopen(input_file);

where the name of file it's what i write, if i call "program('test')" the is input_file = ('test.inp');

I tried this:

if exist ('file','var')
    input_file = ('file.inp');
    fid = fopen(input_file);

but doesn't work.

Any help?

Answer 1

[Walter Roberson]

input_file = [file '.inp'];

[Marco]

Thank you very much!!

Answer 2

[Jos (10584)]

Create a function m-file, where you can use a variable.

function MyProgram (MyInputFile)
% MYPROGRAM (FILE) opens the file with the name FILE, if it exists.
% Use it like this: >> MyProgram('test.dat')
if exist (MyInputFile, 'file')
  fid = fopen(MyInputFile,'rt') 
  % do something useful here
  fclose(fid) ;
else
  disp(['The file ' MyInputfile ' does not exist.']) ;
end

[Marco]

Thank you!