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

/**
 * Trim whitespace off front and back of string
 * Assumes a well-formatted (null terminated) string
 **/
char* trim(char* target)
{
    while (' '==*target || '\t'==*target)
	target++;
    char* trailer = target;
    while ('\0' != *trailer)
    {
	trailer++;
    }
    if (trailer!=target)
    {
	trailer--;
	while (' '==*trailer || '\t'==*trailer)
	{
	    *trailer='\0';
	    trailer--;
	}
    }
    return target;
}


void trimTest(char* target)
{
    char retar[strlen(target+4)];
    strcpy(retar, target);
    
    printf("ORIGINAL ||%s||\n", retar);
    char* ttarget = trim(retar);
    if (ttarget==retar)
    {
	printf("No leading whitespace\n");
    }
    printf("TRIMMED  ||%s||\n", ttarget);
}

int main(void)
{
    trimTest("   this is a test");
    trimTest("A second test   ");
    trimTest("\tThird");
}