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/* Copyright 1998 by the Massachusetts Institute of Technology. 
 * 
 * Permission to use, copy, modify, and distribute this 
 * software and its documentation for any purpose and without 
 * fee is hereby granted, provided that the above copyright 
 * notice appear in all copies and that both that copyright 
 * notice and this permission notice appear in supporting 
 * documentation, and that the name of M.I.T. not be used in 
 * advertising or publicity pertaining to distribution of the 
 * software without specific, written prior permission. 
 * M.I.T. makes no representations about the suitability of 
 * this software for any purpose.  It is provided "as is" 
 * without express or implied warranty. 
 */ 
 
#include "ares_setup.h" 
 
#include "ares.h" 
#include "ares_nowarn.h" 
#include "ares_private.h" 
 
/* This is an internal function.  Its contract is to read a line from 
 * a file into a dynamically allocated buffer, zeroing the trailing 
 * newline if there is one.  The calling routine may call 
 * ares__read_line multiple times with the same buf and bufsize 
 * pointers; *buf will be reallocated and *bufsize adjusted as 
 * appropriate.  The initial value of *buf should be NULL.  After the 
 * calling routine is done reading lines, it should free *buf. 
 */ 
int ares__read_line(FILE *fp, char **buf, size_t *bufsize) 
{ 
  char *newbuf; 
  size_t offset = 0; 
  size_t len; 
 
  if (*buf == NULL) 
    { 
      *buf = ares_malloc(128);
      if (!*buf) 
        return ARES_ENOMEM; 
      *bufsize = 128; 
    } 
 
  for (;;) 
    { 
      int bytestoread = aresx_uztosi(*bufsize - offset); 
 
      if (!fgets(*buf + offset, bytestoread, fp)) 
        return (offset != 0) ? 0 : (ferror(fp)) ? ARES_EFILE : ARES_EOF; 
      len = offset + strlen(*buf + offset); 
      if ((*buf)[len - 1] == '\n') 
        { 
          (*buf)[len - 1] = 0; 
          break; 
        } 
      offset = len; 
      if(len < *bufsize - 1) 
        continue; 
 
      /* Allocate more space. */ 
      newbuf = ares_realloc(*buf, *bufsize * 2);
      if (!newbuf) 
        {
          ares_free(*buf);
          *buf = NULL;
          return ARES_ENOMEM;
        }
      *buf = newbuf; 
      *bufsize *= 2; 
    } 
  return ARES_SUCCESS; 
}