BASIC OF FILE I/O

Problem 86: File write

Write a program that opens a file named myFile.txt on write mode and write 100(integer) into that file.

Code:

 

    #include<stdio.h> 
 
main() {
   FILE *fp;

   fp = fopen("myFile.txt", "w");
   fprintf(fp, "%d", 100);
   fclose(fp);
}

Problem 87: Delete Text

Write a program which will delete all the text from a text file and write “LOVE” on that file.

Code:

 

    #include<stdio.h> 
 
int main() {
   FILE *fp;
   fp = fopen("myFile.txt", "w");
   fprintf(fp, "%s", "Love");

return 0;
}

Problem 88: Append

Write a program which will create a file named myFile.txt and write “We LovE” on that file. Then read the file and print the text of that file into console. Finally, append “Our Country” with the previous text of that file and print the whole text again into console.

Code:

 

    #include<stdio.h> 
 
int main()
{
    int c;
    FILE *file;

    file = fopen("newFile.txt", "w");
    fprintf(file, "%s", "We Love");
    fclose(file);

    file = fopen("newFile.txt", "r");
    if (file) {
        while ((c = getc(file)) != EOF)
            putchar(c);
        fclose(file);
    }
    printf("\n");

    file=fopen("newFile.txt", "a");
    fprintf(file,"%s"," Our Country");
    fclose(file);

    file = fopen("newFile.txt", "r");
    if (file) {
        while ((c = getc(file)) != EOF)
            putchar(c);
        fclose(file);
    }

}

Problem 89: Read File

Create a text file in your computer and write 10 integers in 10 separate lines. Now write a program which will open the file and read that 10 integers. Finally print the average of that ten integers.

Code:

 

    #include<stdio.h> 
 
int main()
{
    FILE *file;
    int n[10];
    int i=0,sum=0;

    file = fopen("integers89.txt", "r");
    while(fscanf(file,"%d",&n[i])!=EOF)
         i++;
    for(i =0;i < 10 ;i++)
    {
        sum=sum+n[i];
    }
    printf("%.2f",sum/10.0);

}

Problem 90: Paragraph

Create a text file in your computer and write a paragraph about INTERNET on that file. Then write a program which will open that file and print the whole paragraph into console.

Code:

 
      	
        #include<stdio.h>

int main()
{
    char par[100000];
    FILE *file;
    file=fopen("paragraph.txt","r");
    while(fgets(par,10000,file))
    {
        printf("%s",par);
    }
    printf("\n");
}