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