Thread: Returning to Main Menu after modifying variable(s) and/or "Error!"

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Hopefully this posts correctly. I'm looking to return to the main menu (see comments below). Thank you

Code:

#include <stdio.h>
#include <string.h>


char pswd[20] = "password"; // Password
char inpt[20] = "_";        // User Input
char ysno[3]  = "yes";      // Yes or No? (menu || exit)
int choice;                 // Main Menu Selection
int lenInpt;                // User Input Length
int lenPswd;                // Password Length
int result;                 // Result of strcmp(1,2)


/* Looking for an option to return to main menu when a process is completed or the user input has an error */


// Changing Password
int chngePswd(){
    printf("\n\tEnter your new password\t(max 20 characters)\n\n\tPassword: ");
    scanf("%s", inpt);
    int lenInpt = strlen(inpt); if(lenInpt > 20){
        printf("\tError! Your password must have less than 20 charachters\n\nLogging off…\n");
        // ‹Return to MAIN MENU›
        return 1;
    }
    strcpy(pswd, inpt); printf("\nYour password has been updated\n");
    // ‹Return to MAIN MENU›
    return 0;
}


// Displaying Password
int dsplyPswd(){
    printf("\n\tYour password is \"%s\"\n", pswd);
    int lenPswd = strlen(pswd);
    printf("\tThe length of your password is %d charachters\n\n", lenPswd);
    printf("Return to the main menu?\tEnter |yes| or |no|\n"); scanf("%s", inpt);
    int result = strcmp(ysno, inpt);
    if(result == 0){
        // ‹Return to MAIN MENU›
    }else{
        printf("Logging off…\n");
        return 1;
    }
    return 0;
}


// Login & Main Menu
int main(){
    printf("Password: ");
    scanf("%s", inpt);
    int result = strcmp(pswd,inpt);
    if(result == 0){
        printf("\n\tYou are now logged in\n\n「Main Menu」\n1\tChange Password\n2\tDisplay Password\n3\tLog Out\n\nSelection: ");
        scanf( "%d", &choice);
        switch(choice){
            case 1:
                chngePswd();
                break;
            case 2:
                dsplyPswd();
                break;
            case 3:
                printf("Logging off…\n\n\tThank you for using this app!\n");
                break;
            default:
                printf("Invalid Input!\n\nLogging out…\n");
                // ‹Return to MAIN MENU›
                 }
}
    else{
        printf("\n\tIncorrect Password!\n\n");
        // ‹Return to MAIN MENU›
        return 1;
    }
    return 0;
}

You should now try to do this with appropriate loops, not using goto's.

> if(lenInput > 20)
You never get to do this.
Sure, you can type in more than 21 characters, but your program is crippled from the moment the user enters the 21st character.
Ideally, use
char buff[BUFSIZ];
fgets(buff,BUFSIZ,stdin);

BUFSIZ is usually large (defined in stdio.h), and fgets() ensures you never have a buffer overflow.
Now use strlen() to determine if the input meets your other requirements.

But a word of warning, if you're going to use fgets(), beware that it doesn't play nice with scanf functions.
It's generally best to use fgets() for ALL input, then use sscanf, strlen, strcpy, strtod, ... to do the necessary validation and conversion on an in-memory string.