/* # integer-ok.c: test if a string is a valid integer. # # Copyright (C) 1992, 2011 Free Software Foundation, Inc. # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . # */ #include "config.h" #include "c-ctype.h" boolean integer_ok (string str) { boolean found_digit = false; if (str == NULL) return false; /* Allow leading `-' or `+' sign. */ if (*str == '-' || *str == '+') str++; /* Skip decimal digits. */ while (ISDIGIT (*str)) { str++; found_digit = true; } return *str == 0 && found_digit; }