Question

I need this code to be written in C language. Also, I'm using Xcode on mac so I need the steps in order to know how to do it.

Please save the program with the name 'files.c' Write a program that merges two files as follows. The two files are in the docsharing which you can download it. One file will contain usernames (usernames.txt): foster001 smith023 nyuyen002 The other file will contain passwords (passwords.txt): x34rdf3e P43e4rdd w32eds22 The program should create a third file matching username and passwords (usernamesPasswords.txt): fostero01 smith023 nyuyen002 x34rdf3e P43e4rdd w32eds22 Give the user of your programs the option of displaying you output file.

Answer 1

The completed C program is given below. I've added comments to explain what each line of code does. In the first section I have added the Source Code and Sample Output. In the next section I have added instructions for creating a C project on XCode:

Source Code:

#include <stdio.h>

//we define a maximum length for our strings as

#define MAX_LEN 500

int main() {

    //Declare three file pointers. We will use fp1 and fp2 to read our files

    //and fp3 to write the merged content into another file

    FILE *fp1, *fp2, *fp3;

    //define two strings (character arrays) for input of username and password from input files

    char username[MAX_LEN];

    char password[MAX_LEN];

    //try to open users.txt for reading

    fp1 = fopen("users.txt","r");

    //if fopen returns NULL, file couldn't be opened. Show an error message and return

    if(fp1 == NULL) {

        printf("File Read Error. Aborting....");

        return 1;

    }

    //try to open passwords.txt for reading

    fp2 = fopen("passwords.txt","r");

    //if fopen returns NULL, file couldn't be opened. Show an error message and return

    if(fp2 == NULL) {

        printf("File Read Error. Aborting....");

        return 2;

    }

    //try to open usernamesPasswords.txt for writing

    fp3 = fopen("usernamesPasswords.txt","w");

    //if fopen returns NULL, file couldn't be opened. Show an error message and return

    if(fp3 == NULL) {

        printf("File Read Error. Aborting....");

        return 3;

    }

    //use a while loop to read the files till we reach EOF (End of File character) in either of the'

    //two input files

    while(!feof(fp1) && !feof(fp2)) {

        //read username from users.txt

        fscanf(fp1,"%s",username);

        //read password from passwords.txt

        fscanf(fp2,"%s",password);

        //merge both and write them to usernamesPasswords.txt

        fprintf(fp3,"%s\t%s\n",username,password);

    }

    //close the open files

    fclose(fp1);

    fclose(fp2);

    fclose(fp3);

    //Ask the user if they want to see the merged fies

    char ch;

    printf("Do you want to view the Output files? (Y/N) ");

    scanf("%c",&ch);

    //if they enter y, we print the output file

    if(ch == 'Y' || ch == 'y') {

        //try to open usernamesPasswords.txt for reading

        FILE *fp4 = fopen("usernamesPasswords.txt","r");

        //if fopen returns NULL, file couldn't be opened. Show an error message and return

        if(fp4 == NULL) {

            printf("File Read Error. Aborting....");

            return 4;

        }

        //use a while loop to read the files till we reach EOF (End of File character)

        while(!feof(fp4)) {

            //read the file character by character by character

            char read = fgetc(fp4);

            printf("%c",read);

        }

        //close the file

        fclose(fp4);

    }

    return 0;

}

Sample Output:

$ ./files Do you want to view the Output files? (Y/N) y foster001 x34rdf3e smithe23 P43e4rff nyuyen002 W32eds22

Instructions:

(1) Creating a C Project in X-Code

1. Launch XCode and select "Create a new XCode project"

Welcome to Xcode Version 5.1.1 (561008) Create a new Xcode project Start building a new iPhone, iPad or Mac application. Check out an existing project Start working on something from an SCM repository. Open Other...

1. Then Choose Command Line Tool from the OS-X tab

Choose a template for your new project iOS Application Framework & Library Other Cocoa Application OS X Application Framework & Library Application Plug-in System Plug-in Other Spriteit Game Cocoa-AppleScript Application Command Line Tool Command Line Tool This template builds a command-line tool. Cancel Previous Next

1. Chose a name for your project. Here it is ExampleProject, but you can pick any name you want. Add alos select type as C

Choose options for your new project: Product Name Example Project Organization Name Maxs Company Identifier 131 Bundle Identifier -31.Example Project Type C : ARRATIA Cancel Previous Next

1. Go to the file navigator on the Side Navbar on the left hand side, click on your project name, then click on the file named "main.c"

Xcode File Edit View Find ө00 Example Project My Q A Example Project 1 target, OS X SDK 10.9 Example Project c main.c Example Project. 1 Products

1. Copy paste the code in the main.c file

Xcode File Edit View Find Navigate Editor Product Debug Source Control Wing Example Proje Example Project My Mac 64-bit Example Project: Ready Today at 11:42 QA ExampleProject Example Project main.c No Select Example Project 1 target, OS X SOK 10.9 // main.c Example Project // Example Project C main.c Example Project. 1 Copyright (c) 2014 Maxs. All rights reserved. Products int main(void) #include <stdio.h> snt main(int argc, const char argv[] 1/ // insert code here... printf("Hello, World!\n"); return;

1. Run the file once to create the executable. The first time you will get an output that says "File Read Error. Aborting....". But don't woryy. This will create the executable file. You cna run the program by clicking on the play button in the top-left

Xcode

1. Click on products in the file navigator on the left hand side , and you will see the executable. It will be shown by a black and white icon. Right click on it and select Show in Finder. This will lead you to the location of the executable. In that folder/path save your input files "users.txt" and "passwords.txt". Then run your code again, and it should run correctly

schedule My Mac 64-bit Ta 8 1 < schedule 1 target, OS X SDK 10.9 schedule .e main.c schedule. 1 Products sche Show in Finder Open with External Editor Open As Show File Inspector New File... New Project... acchedule" Add files