Eclipse debugging with input from console

Question

I'm trying to debug a program I wrote in C++ using Eclipse. The program includes getting input from the user but when I enter the input to the console it won't ever continue running the code (it'll keep asking for input). I can't debug without fixing this and would appreciate some help. Thank you.

The code gets stuck on the while loop fgets:

int main(int argc, const char**argv) {
    FILE* inputFile = NULL;

    setlocale(LC_ALL, "");
    if(argc == 2){
        inputFile = fopen(argv[1], "r");
        if (inputFile == NULL){
            printf("Problem opening file %s, make sure correct path name is given.\n", argv[1]);
            return 0;
        }
    }
    else {
        inputFile = stdin;
    }

    char buffer[MAX_STRING_INPUT_SIZE];
    // Reading commands
    while ( fgets(buffer, MAX_STRING_INPUT_SIZE, inputFile) != NULL ) {
        fflush(stdout);
        if ( parser(buffer) == error ){
            printf("ERROR\n");
            break;
        }
    };
    fclose(inputFile);
    return 0;
}

Do you get the same problem running the program outside of Eclipse as a stand alone executable? — , Jan 14 '13 at 18:42
See if this helps: http://stackoverflow.com/questions/4711098/passing-end-of-transmission-ctrl-d-character-in-eclipse-cdt-console — queen3, Jan 14 '13 at 18:44
Did you check the debug configuration? AFAIR there's some option to assign a console to the executable being debugged. — πάντα ῥεῖ, Jan 14 '13 at 19:06

score 14 · Answer 1 · answered Nov 06 '13 at 23:09

The issue comes from Eclipse buffering the console inputs. One way to fix it is to force Eclipse to debug using a Windows/DOS native console.

The procedure is described in details here, but in brief :

Create your Hello World C++ command line project, from the Eclipse menu File > New > C++ Project
In your project folder, create a ".gdbinit" text file. It will contain your gdb debugger configuration
Edit ".gdbinit", and add the following line (without quotes) : "set new-console on"
In Eclipse, go to menu Run > "Debug Configurations", and select your application name in the left pane
In the "debugger" tab, ensure the "GDB command file" now points to your « .gdbinit » file. Else, input the path to your ".gdbinit" configuration file
Click « Apply » and « Debug ». You’re done ! A native DOS command line should be launched.

how to stop Eclipse buffering the console inputs while 'Running the Application As'(not dedugging) too? — Vikas Prasad, Apr 15 '17 at 15:18

score 0 · Answer 2 · edited May 23 '17 at 10:30

Well I know that Eclipse console buffer doesn't always work as it should - in my experiences, it's the worst when using C or C++.

If you want to run your compiled code in Eclipse, this will greatly help but not eliminate the display issues you might encounter in Eclipse:

setvbuf(stdout, NULL, 0, _IONBF);

However, I don't know how this affects debugging in Eclipse while using stdin. Your best option is to use Nicolas's answer to run through the DOS console. A bit more work, but it will suffice I believe.

And please note that the above line should only be used while running your code through Eclipse, in order to have some kind of sane output buffer without several messy in-code workarounds. This line needs to be commented out when compiling for actual use.

Eclipse debugging with input from console

2 Answers2

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