return a pointer (char *) to a str substring

crux-00011: $SRC/str/str_view.c

#include "str/str.h"
#include "utils/panic.h"

char *
str_view (struct str * s, int pos, int l)
{
  if (pos < 0) panic ("string position below 0");
  if (pos >= s->l) panic ("substring length too large");
  if (l < 0) panic ("substring length below 0");
  if ((pos + l) > s->l) panic ("substring length too large");
  return s->s + pos;
}

/*

    This file is part of Crux.

    Crux 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.

    Crux 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 Crux.  If not, see <http://www.gnu.org/licenses/>.

*/