CLion standard input while debugging

Question

What I'm trying to do is basically:

./myProgram < myData.txt

While I'm debugging with CLion IDE. I just can't find the option to do so.

A similar question - but product-specific to MSVS

Answer 1

I had the same problem and it seems that CLion is not handling standard inputs yet.

I got around this problem by changing the input stream before running my program.

As an example if you want to input a file stream inside your stdin you can write in your main:

std::ifstream in("ABSOLUTE_PATH_TO_YOUR_FILE");
std::cin.rdbuf(in.rdbuf());

Then you can find a way to toggle this stream change when you want. Note that for files you will need to provide absolute path since the application is run from a different directory than the current one.

I hope this can help until CLion provides a real solution.

Answer 2

Assuming your input file is myData.txt, you can reopen/reuse the stdin stream using freopen

freopen("myData.txt","r",stdin);

if you want to do the same with your output:

freopen("myOutput.txt","w",stdout);

this will work for std::cin, printf, etc...

You can find more information about this here: http://www.cplusplus.com/reference/cstdio/freopen/

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By the way, there is already a feature request for this. If you are interested, you can vote here so it gets prioritized: https://youtrack.jetbrains.com/issue/CPP-3153

Answer 3

As of CLion 2020.1 this feature is built in:

Input redirection

If you need to redirect input from a file to the stdin of your application, you can now do that. Use a new field in the configuration called Redirect input from. Enter:

• A relative path (CLion will prepend with the Working directory path).
• An absolute path (will be remapped for remote configurations).
• Or macros (like FilePrompt).