compare version

compare_version.c

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

int compareVersion(const char *v1, const char *v2)
{
	char *f1, *f2, *s1, *s2;
	int n1, n2, r;
	f1 = s1 = strdup(v1);
	f2 = s2 = strdup(v2);
	do {
		n1 = s1 ? atoi(strsep(&s1, ".")) : 0;
		n2 = s2 ? atoi(strsep(&s2, ".")) : 0;
		r = n1 - n2;
	} while (!r && (s1 || s2));
	free(f1);
	free(f2);
	return r;
}

int main()
{
	printf("%d\n", compareVersion("1.2.0", "1.2.-1"));
	printf("%d\n", compareVersion("1.2.1", "1.2.0"));
	printf("%d\n", compareVersion("12.2", "2.2.0"));
	printf("%d\n", compareVersion("1.2.1", "1.2"));
	printf("%d\n", compareVersion("1.2.3", "1.2.1"));
	printf("%d\n", compareVersion("1.2.3", "1"));
	printf("%d\n", compareVersion("1", "1.0.3.1"));
	printf("%d\n", compareVersion("1.2.3", "1.0.10"));
	printf("%d\n", compareVersion("1.0.3", "1.1.10"));
	printf("%d\n", compareVersion("1.1.03", "1.1.3"));
	printf("%d\n", compareVersion("1.1.03", ""));
	printf("%d\n", compareVersion("", "1.20"));
}