check command line input is a number in c

bool isNumber(char number[])<br /> {<br /> int i = 0;</p> <p> //checking for negative numbers<br /> if (number[0] == ‘-‘)<br /> i = 1;<br /> for (; number[i] != 0; i++)<br /> {<br /> //if (number[i] > ‘9’ || number[i] < ‘0’)<br /> if (!isdigit(number[i]))<br /> return false;<br /> }<br /> return true;<br /> }