hello,
i wanna ask you about a program that he save the password that you have entered the last time and he ask you to entered it again if you want to continue and open it, so the most important part is to save the password that you have entered.
thanks.
Save it in an external database, file, or inside the program memory itself?
Post your code.
this is my code, and i want to save the name that i have entered
Code:#include<stdio.h>
#include<string.h>
int main (void)
{
char answer1[100];
char answer2[100];
printf("what's your name?\n");
scanf("%s",&answer1);
printf("what's your name?\n");
scanf("%s",&answer2);
if(strcmp(answer1,answer2)==0)
{
printf("good\n");
}
else
{
printf("not good\n");
}
return 0;
Is this just a beginner exercise? If so, you can just save the password in a file as plain-text, and read it from the file when it's time to do the comparison.
If you want real password protection, it will be more complicated.
Once again, do you want to save it to an external file/database or inside the programs memory?
First things first. When your scanf needs to take a pointer to your char array. As of right now you have a pointer to a pointer. The name of the array is essentially a pointer to the first element in the array, meaning that scanf will suffice with the following
Code:scanf("%s",answer1); //notice how the '&' was removed
i want to save it inside the programs memoryQuote:
Once again, do you want to save it to an external file/database or inside the programs memory?
Do what you are doing with the "answers", except make sure you apply the change I mention in the scanf.
i didn't understand anything , i'm asking about saving the name taht the user choise, like when a simple program ask you to enter your password and when you forget it he tell you that your password is not valid, i'm sure that my question is clear, but i don't know why the answers is not clear!:confused:
You can only do two things:
1) Save the input onto the disk.(Requires that you create a text-file.)
2) Save the program to RAM.(Data will disappear once the program has terminated.)
To save data to a file first you need to create a file pointer to point to a file we will use to save user input.
Also, we will use fgets() function instead of the scanf() function.Code:FILE fp;
Full program to save user data:
Code:#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NAMECAP 15
//Holds user data.
struct data {
char *password;
char *username;
}info;
/*
***********************
*****Program Start*****
***********************
*/
int main(void)
{
//File pointer.
FILE *fp;
/*
**********************
********MENU**********
**********************
*/
//Get username.
printf("\nWhat is your username?: ");
info.username = (char*)malloc(NAMECAP * sizeof(char)); //Dynamically allocate memory.
if(info.username == NULL)
{
printf("\nError: Out of memory.\n");
exit(0);
}
fgets(info.username, NAMECAP, stdin);
info.username[strlen(info.username)-1] = '\0'; //Remove '\n' from input.
//Get password.
printf("What is your password?: ");
info.password = (char*)malloc(NAMECAP * sizeof(char)); //Dynamically allocate memory.
if(info.password == NULL)
{
printf("\nError: Out of memory.\n"); //If failed.
exit(0);
}
fgets(info.password, NAMECAP, stdin);
info.password[strlen(info.password)-1] = '\0'; //Remove '\n' from input.
//Open file for appending, create a new one if it doesn't already exist.
if((fp = fopen("data.txt", "a+")) == NULL)
{
printf("\nCould not open file.\n\n"); //If failed.
exit (0);
}
fprintf(fp,"%s\n%s",info.username,info.password); //Write to file with fprintf().
printf("%s\n%s\n",info.username,info.password); //Output to screen.
//Close file.
fclose(fp);
//Free up memory.
free(info.password);
free(info.username);
//Exit program.
exit(0);
}
Correction for the first code snippet - pointer declaration should have a star to create a file pointer:
Code:FILE *fp;
he don't save the password, i can enter every password i want:(!
Post your updated code.