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C Program To Write A File

    C programming allows to read or write files. In this program, a user will enter some text which will be stored in a file using file operations in C.

    Learn C programming concepts, before you begin with this example.

    Problem Definition

    The program demonstrate the C language ability to write to file and it is achieved with the help of following C language features.

    FILE – a file structure data type which is usually hidden from users.

    fopen() – builtin function to open a file in buffer, so that you can read or write to file.

    fprintf() – a print function to write to file from console.

    fclose() – close the file and file pointer.

    Program Source Code

    Before you start executing the program, make sure you have created a file called demo.txt in the same directory where the program resides.

    #include <stdio.h>
    #include <stdlib.h>
    int main()
    {
        char c[1000];
        FILE *fptr;
        fptr = fopen("demo.txt","w");
        if(fptr == '\0')
        {
            printf("Error!!\n");
            exit(1);
        }
        printf("Enter a Sentence:\n\n");
        gets(c);
            fprintf(fptr,"%s", c);
            fclose(fptr);
        system("PAUSE"); 
        return 0;
    }

    Output

    When run the program, it will ask for a sentence from user as input. See the diagram below, type the sentence you want to write to the file and press enter.

    Enter a Sentence:
    
    OMG ! This is a big red horse.
    Press any key to continue . . . 

    You must go to the directory where the C program resides and open the file – demo.txt. The content of the console is written to the file successfully.

    Output - Program to Write to a File
    Output – Program to Write to a File