Question

Write a C program that will act as a database access tool.

Three separate functions are needed to:

1. Print dates

2. Print names

3. Print category numbers and the average of the numbers.

A random text file (from notepad) is supplied for the dates, names, and category's.

For Example:

Storm name: Storm Date: Storm category number:

The program must ask the user which of the three items listed above they want to run instead of dumping all of the information at once.

Answer 1

Code:

#include<stdio.h>
#include<string.h>
void print_dates(char line[][128], int cnt)//prints dates
{
   int i, j;
   for(i=0;i<cnt;i++)
   {
       for(j=0;line[i][j]!='\0';j++)
       {
           if(line[i][j]!=' ') printf("%c",line[i][j]);//print characters until there's a space
           else break;
       }
       printf("\n");
   }
}
void print_names(char line[][128], int cnt)
{
   int i, j;
   for(i=0;i<cnt;i++)
   {
       for(j=0;line[i][j]!='\0';j++)
       {
           if(line[i][j]==' ') break;//skip until a space is encountered
       }
       j++;
       for(;line[i][j]!='\0';j++)
       {
           if(line[i][j]!=' ') printf("%c",line[i][j]);//print thereafter
           else break;
       }
       printf("\n");
   }
}
void print_numbers(char line[][128], int cnt)
{
   int i, j;double avg = 0;
   for(i=0;i<cnt;i++)
   {
       double total = 0;//stores number in every line
       for(j=0;line[i][j]!='\0';j++)
       {
           if(line[i][j]==' ') break;//skip until two spaces are encountered
       }
       j++;
       for(;line[i][j]!='\0';j++)
       {
           if(line[i][j]==' ') break;
       }
       j++;
       for(;line[i][j]!='\0';j++)
       {
           if(line[i][j]!='\n')
           {
               printf("%c",line[i][j]);//print the rest characters
               total = (total * 10) + (line[i][j] - '0');//characters to number
           }
           else break;
       }
       avg += total;//sum all the numbers
       printf("\n");
   }
   avg = avg/cnt;//calculate average
   printf("Average: %lf\n", avg);
}
int main()
{
   FILE *fp = fopen("example.txt","r");//open file
   char line[100][128];int cnt = 0, i = 0;//line stores file's contents, cnt stores no. of lines in the file
   while(fgets(line[i++], sizeof line, fp) != NULL)
   {
       cnt++;
   }
   printf("Which item do you want, Date, Name or Number: ");
   char inp[200];scanf("%s",inp);
   if(strcmp(inp,"Date") == 0)
   {
       print_dates(line, cnt);
   }
   else if(strcmp(inp, "Name") == 0)
   {
       print_names(line, cnt);
   }
   else if(strcmp(inp, "Number") == 0)
   {
       print_numbers(line, cnt);
   }
   else
   {
       printf("You have entered an invalid option\n");
   }
   return 0;
}

Output: