This one includes integer fractions ...
Code:
int isNumber( char *string ) {
int oneDot = 0, stringLength = strlen(string), ii;
for (int i=0; i<stringLength; i++) {
ii = (int)string[i];
if ( !(ii >= 48 && ii <= 57) ) {
if ( ii != '.' && ii != '/') {
return 0;
} else {
if (oneDot++ > 0 || (i < 1 && stringLength == 1)) {
return 0;
}
}
}
}
return 1;
}