The program file p1.c below compiles under Linux to create an object file p1.o. It is to be linked with another file p2.o to create a running program, whole.
Solution:
/* p1.c
*/
#include <stdlib.h>
#include <stdio.h>
// PURPOSE: To tell the maximum length of a C-string.
#define MAX_LENGTH 64
// PURPOSE: To hold the number that the user enters.
int guessedNumber;
// PURPOSE: To hold the true random number.
extern int trueNumber;
// PURPOSE: To repeated use 'getInteger()' to get a value for 'guessedNumber'
// until that value is between 1 and 100. No return value.
extern void enterGuess ();
// PURPOSE: To print 'msgCPtr', allow the user to enter an integer, and
// return that integer.
int getInteger (const char* msgCPtr
)
{
char numberText[MAX_LENGTH];
printf(msgCPtr);
fgets(numberText,MAX_LENGTH,stdin);
return(atoi(numberText));
}
// PURPOSE: To:
// * print "Too low!\n" and return 0 if guessedNumber < trueNumber,
// * print "Too high!\n" and return 0 if guessedNumber > trueNumber, or
// * print "Congratulations!\n" and return 1 if they are equal.
extern int wasGuessCorrect ();
// PURPOSE: To return a random number between 1 to 100. No parameters.
int chooseRandomNumber ()
{
return( (rand() % 100) + 1 );
}
// PURPOSE: To seed the random number generator with the number given in
// 'argv[1]' (if 'argc' is at least 2) and allow the user to guess a
// randomly-chosen number between 1 and 100 inclusive. Returns
// 'EXIT_SUCCESS' to the OS after the number is guessed.
int main (int argc,
char* argv[]
)
{
if (argc > 1)
srand(atoi(argv[1]));
trueNumber = chooseRandomNumber();
do
{
enterGuess();
}
while ( wasGuessCorrect() == 0 );
return(EXIT_SUCCESS);
}
Sample output:
[instructor@JoesLaptopFedora16 Assign1]$ gcc p1.c -c
[instructor@JoesLaptopFedora16 Assign1]$ gcc p2.c -c
[instructor@JoesLaptopFedora16 Assign1]$ gcc p1.o p2.o -o whole
[instructor@JoesLaptopFedora16 Assign1]$ ./whole 1
Please enter your guess 1-100: 50
Too low!
Please enter your guess 1-100: 75
Too low!
Please enter your guess 1-100: 87
Too high!
Please enter your guess 1-100: 81
Too low!
Please enter your guess 1-100: 84
Congratulations!
[instructor@JoesLaptopFedora16 Assign1]$ ./whole 2
Please enter your guess 1-100: 50
Too low!
Please enter your guess 1-100: 75
Too low!
Please enter your guess 1-100: 87
Too low!
Please enter your guess 1-100: 93
Too high!
Please enter your guess 1-100: 90
Too low!
Please enter your guess 1-100: 91
Congratulations!
[instructor@JoesLaptopFedora16 Assign1]$ ./whole 3
Please enter your guess 1-100: 50
Too high!
Please enter your guess 1-100: 25
Too low!
Please enter your guess 1-100: 37
Too low!
Please enter your guess 1-100: 43
Too low!
Please enter your guess 1-100: 47
Congratulations!
[instructor@JoesLaptopFedora16 Assign1]$
(30 Points) Write an elegant program file p2.c that would compile to p2.o, and would link with p1.o to create a legal running program whole.
Important: Include your p2.c with your submission!
HINTS:
What does p1.c need that it does not define?
Create the individual object files and the complete executable with:
linux> gcc -c p1.c # creates p1.o
linux> gcc -c p2.c # creates p2.o
linux> gcc p1.o p2.o -o whole # creates whole
linux> ./whole # runs whole