Debugging is the process of finding and fixing errors in software that prevents it from running correctly. As you become a more advanced programmer and an industry engineer, you will learn how to use debugging tools such as gdb or built-in tools that IDEs have. However, it’s important to understand the concepts and processes of debugging manually.
- Allowed editors: vi, vim, emacs
- All your files will be compiled on Ubuntu 14.04 LTS
- Your programs and functions will be compiled with gcc 4.8.4 using the flags -Wall -Werror -Wextra and -pedantic
- All your files should end with a new line
- Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl
- A README.md file at the root of the holbertonschool-low_level_programming repo, containing a description of the repository
- A README.md file, at the root of the folder of this project (i.e. 0x03-debugging), describing what this project is about
0. Multiple mains
Files: 0-main.c - holberton.h
In most projects, we often give you only one main file to test with. For example, this main file is a test for a postitive_or_negative() function similar to the one you worked with in an earlier C project:
carrie@ubuntu:/debugging$ cat main.c
#include "holberton.h"
/**
* main - tests function that prints if integer is positive or negative
* Return: 0
*/
int main(void)
{
int i;
i = 98;
positive_or_negative(i);
return (0);
}
carrie@ubuntu:/debugging$
carrie@ubuntu:/debugging$ cat holberton.h
#ifndef HOLBERTON_H
#define HOLBERTON_H
#include <stdio.h>
void positive_or_negative(int i);
#endif /* HOLBERTON_H */
carrie@ubuntu:/debugging$
carrie@ubuntu:/debugging$ gcc -Wall -pedantic -Werror -Wextra positive_or_negative.c main.c
carrie@ubuntu:/debugging$ ./a.out
98 is positive
carrie@ubuntu:/debugging$Based on the main.c file above, create a file named 0-main.c. This file must test that the function positive_or_negative() gives the correct output when given a case of 0.
You are not coding the solution / function, you’re just testing it! However, you can adapt your function from 0x01. C - Variables, if, else, while - Task #0 to compile with this main file to test locally.
- You only need to upload 0-main.c and holberton.h for this task. We will provide our own positive_or_negative() function.
- You are not allowed to add or remove lines of code, you may change only one line in this task.
carrie@ubuntu:/debugging$ gcc -Wall -pedantic -Werror -Wextra positive_or_negative.c 0-main.c -o 0-main
carrie@ubuntu:/debugging$ ./0-main
0 is zero
carrie@ubuntu:/debugging$ wc -l 0-main.c
16 1-main.c
carrie@ubuntu:/debugging$ 1. Like, comment, subscribe
Files: 1-main.c
Copy this main file. Comment out (don’t delete it!) the part of the code that is causing the output to go into an infinite loop.
- Don’t add or remove any lines of code, as we will be checking your line count. You are only allowed to comment out existing code.
- You do not have to compile with -Wall -Werror -Wextra -pedantic for this task.
carrie@ubuntu:/debugging$ cat 1-main.c
#include <stdio.h>
/**
* main - causes an infinite loop
* Return: 0
*/
int main(void)
{
int i;
printf("Infinite loop incoming :(\n");
i = 0;
while (i < 10)
{
putchar(i);
}
printf("Infinite loop avoided! \\o/\n");
return (0);
}
carrie@ubuntu:/debugging$Your output should look like this:
carrie@ubuntu:/debugging$ gcc 1-main.c -o 1-main
carrie@ubuntu:/debugging$ ./1-main
Infinite loop incoming :(
Infinite loop avoided! \o/
carrie@ubuntu:/debugging$ wc -l 1-main.c
24 1-main.c
carrie@ubuntu:/debugging$
2. 0 > 972?
Files: 2-largest_number.c - holberton.h
This program prints the largest of three integers.
carrie@ubuntu:/debugging$ cat 2-main.c
#include <stdio.h>
#include "holberton.h"
/**
* main - prints the largest of 3 integers
* Return: 0
*/
int main(void)
{
int a, b, c;
int largest;
a = 972;
b = -98;
c = 0;
largest = largest_number(a, b, c);
printf("%d is the largest number\n", largest);
return (0);
}
carrie@ubuntu:/debugging$carrie@ubuntu:/debugging$ cat 2-largest_number.c
#include "holberton.h"
/**
* largest_number - returns the largest of 3 numbers
* @a: first integer
* @b: second integer
* @c: third integer
* Return: largest number
*/
int largest_number(int a, int b, int c)
{
int largest;
if (a > b && b > c)
{
largest = a;
}
else if (b > a && a > c)
{
largest = b;
}
else
{
largest = c;
}
return (largest);
}carrie@ubuntu:/debugging$
carrie@ubuntu:/debugging$ gcc -Wall -Werror -Wextra -pedantic 2-largest_number.c 2-main.c -o 2-main
carrie@ubuntu:/debugging$ ./2-main
0 is the largest number
carrie@ubuntu:/debugging$? That’s definitely not right.
Fix the code in 2-largest_number.c so that it correctly prints out the largest of three numbers, no matter the case.
- Line count will not be checked for this task.
3. Leap year
Files: 3-print_remaining_days.c - holberton.h/
This program converts a date to the day of year and determines how many days are left in the year, taking leap year into consideration.
carrie@ubuntu:/debugging$ cat 3-main_a.c
#include <stdio.h>
#include "holberton.h"
/**
* main - takes a date and prints how many days are left in the year, taking
* leap years into account
* Return: 0
*/
int main(void)
{
int month;
int day;
int year;
month = 4;
day = 01;
year = 1997;
printf("Date: %02d/%02d/%04d\n", month, day, year);
day = convert_day(month, day);
print_remaining_days(month, day, year);
return (0);
}
carrie@ubuntu:/debugging$
carrie@ubuntu:/debugging$ cat 3-convert_day.c
#include "holberton.h"
/**
* convert_day - converts day of month to day of year, without accounting
* for leap year
* @month: month in number format
* @day: day of month
* Return: day of year
*/
int convert_day(int month, int day)
{
switch (month)
{
case 2:
day = 31 + day;
break;
case 3:
day = 59 + day;
break;
case 4:
day = 90 + day;
break;
case 5:
day = 120 + day;
break;
case 6:
day = 151 + day;
break;
case 7:
day = 181 + day;
break;
case 8:
day = 212 + day;
break;
case 9:
day = 243 + day;
break;
case 10:
day = 273 + day;
break;
case 11:
day = 304 + day;
break;
case 12:
day = 334 + day;
break;
default:
break;
}
return (day);
}
carrie@ubuntu:/debugging$carrie@ubuntu:/debugging$ cat 3-print_remaining_days.c
#include <stdio.h>
#include "holberton.h"
/**
* print_remaining_days - takes a date and prints how many days are
* left in the year, taking leap years into account
* @month: month in number format
* @day: day of month
* @year: year
* Return: void
*/
void print_remaining_days(int month, int day, int year)
{
if ((year % 4 == 0 || year % 400 == 0) && !(year % 100 == 0))
{
if (month >= 2 && day >= 60)
{
day++;
}
printf("Day of the year: %d\n", day);
printf("Remaining days: %d\n", 366 - day);
}
else
{
if (month == 2 && day == 60)
{
printf("Invalid date: %02d/%02d/%04d\n", month, day - 31, year);
}
else
{
printf("Day of the year: %d\n", day);
printf("Remaining days: %d\n", 365 - day);
}
}
}
carrie@ubuntu:/debugging$ carrie@ubuntu:/debugging$ gcc -Wall -Werror -Wextra -pedantic 3-convert_day.c 3-print_remaining_days.c 3-main_a.c -o 3-main_a
carrie@ubuntu:/debugging$ ./3-main_a
Date: 04/01/1997
Day of the year: 91
Remaining days: 274
carrie@ubuntu:/debugging$Output looks good for 04/01/1997! Let’s make a new main file 3-main_b.c to try a case that is a leap year: 02/29/2000.
carrie@ubuntu:/debugging$ gcc -Wall -Werror -Wextra -pedantic 3-convert_day.c 3-print_remaining_days.c 3-main_b.c -o 3-main_b
carrie@ubuntu:/debugging$ ./3-main_b
Date: 02/29/2000
Invalid date: 02/29/2000
carrie@ubuntu:/debugging$? That doesn’t seem right.
Fix the print_remaining_days() function so that the output works correctly for all dates and all leap years.
Line count will not be checked for this task.
- You can assume that all test cases have valid months (i.e. the value of month will never be less than 1 or greater than 12) and valid days (i.e. the value of day will never be less than 1 or greater than 31).
- You can assume that all test cases have valid month/day combinations (i.e. there will never be a June 31st or November 31st, etc.), but not all month/day/year combinations are valid (i.e. February 29, 1991 or February 29, 2427).