lib/integer-ok.c


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# 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 <http://www.gnu.org/licenses/>.
#


#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;
}