rem: environ[envindex] = (char *)malloc ((unsigned)len + val_len + 1); sprintf (environ [envindex], "%s%s", var, value);
add: environ[envindex] = (char *)malloc ((unsigned)len + val_len + 2); sprintf (environ [envindex], "%s=%s", var, value);
context: Setenv(const char *var, const char *value){	int envindex = 0;	const int len = strlen(var);	const int val_len = strlen (value);  	while (environ [envindex] != NULL) {		if (strncmp (environ [envindex], var, len) == 0) {			/* found it */			environ[envindex] = (char *)malloc ((unsigned)len + val_len + 1);			sprintf (environ [envindex], "%s%s", var, value);			return;		}		envindex ++;	}		environ [envindex] = (char *) malloc ((unsigned)len + val_len + 1);	sprintf (environ [envindex], "%s%s", var, value);	environ [++envindex] = NULL;}