Thread: Cannot find my error

Hi there, I am trying to create a function that takes in any integer and convert it into a string. For example 1000 ---> "1000".

I have gone through an hour trying to figure out my error, but I just can't find it, so I've decided to seek help...here's my code:

Code:

#include <stdio.h>#include <stdlib.h>
#include <math.h>
#include <string.h>




char intToCh(int i) {
	char char_result;
	char character_array[36] = 		{'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};




	char_result = character_array[i];




	return char_result;
	}




char* string_of_int;


char* intToString(int integer) {
	
	int len_of_int = log10(integer) + 1;
	int expon = log10(integer);
	int divider;
	


	int i = 0;


		for(i = 0; i < len_of_int; i++) {
			int temp;


			if (integer == 0) {
				break;
			} else {
			divider = pow(10, expon);
			temp = integer / divider;
			string_of_int[i] = intToCh(temp);
			
			}
			integer = integer - (temp * divider);
			expon--;
		}
	
	return string_of_int;
}










int main(void) {


intToString(1000);






printf("%s\n", string_of_int);








return 0;


}

The compile errors:

Code:

/tmp/cctRlDcq.o: In function `intToString':IntToString.c:(.text+0xe3): undefined reference to `log10'
IntToString.c:(.text+0x100): undefined reference to `log10'
IntToString.c:(.text+0x137): undefined reference to `pow'
collect2: ld returned 1 exit status

I am really confused by the undefined reference because I have already included the math.h library, but it seems like it's not recognized.


Thank you,


-Genxi

Hey Tim,

I've tried compiling with the following:

Code:

gcc -Wall -o IntToString IntToString.c -lm

but, after I ran the code, it gave me the segmentation fault.

Any more ideas?


-Genxi

Thank you for your advices, Tim! I got my code to work after allocating some space and linking by -lm. -high five-!!!

Hmmm ... just use snprintf() if you have a C99 compiler, sprintf() otherwise.

Code:

snprintf(string_of_int, <WHATEVER_SIZE_YOU_ALLOCATED>, "%d", 1000);