Thread: Moving around in functions

The newline from entering the input was left in the input buffer and then read by the next scanf call.

I was unsure of how to ignore the enter, so I've done it in a crude way

Code:

void prompt() {
    char command = '\0';
    int numScanned = 0;
    
    printf("? ");
    numScanned = scanf("%c", &command);
    printf("command = %c\n", command);
    
    while (numScanned == 1) {
        if (command == 'h') {
            helpCommand();
        }
        printf("? ");
        while (command == '\n' || command == ' ' || command == '\t') {
            numScanned = scanf("%c", &command);
        }
        numScanned = scanf("%c", &command);
    }
    
}

Yet it's still not working, and I'm already seeing a problem with this because later on I'm going to need to accept a newline from the user (as opposed to h or any other character I'll also be using). Also, I'm unsure with what other characters can be used besides new lines, spaces and tabs.

EDIT: What I've written clearly doesn't work either. It scans until it finds something other than those blank characters and then it waits to scan again.

EDIT2: Ok I have it working:

Code:

void prompt() {
    char command = '\0';
    int numScanned = 0;
    
    printf("? ");
    numScanned = scanf("%c", &command);
    printf("command = %c\n", command);
    
    while (numScanned == 1) {
        if (command == 'h') {
            helpCommand();
        }
        printf("? ");
        numScanned = scanf("%c", &command);
        while (command == '\n' || command == ' ' || command == '\t') {
            numScanned = scanf("%c", &command);
        }
    }
}

I still have the problem that I'll need to accept a newline character from the user at some point, but I guess I can cross that bridge when I get there.
Also, is it possible to make this more succinct? I find it hard to believe that I need 3 scanfs to just do the one task of scanning.

Here's a more 'concise' version

Code:

void prompt() 
{
    char command = '\0';
    
    printf("? ");
    command = getchar();
    printf("command = %c\n", command);
    
    while (command != exitcharacter)  
    {
        while (xx = getchar() != '\n') ;        // discard the rest of the buffer

        if (command == 'h') 
        {
            helpCommand();
            continue;                               // skip rest of the loop
        }
        // process other characters


        printf("? ");
        command = getchar();
    }
}