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733bb9a054
Run 'make update-copyright'. * lib/regexprops.c (copying): Update the year number manually. * tests/sample-test: Adjust to use the single most recent year. * All other files: Update copyright years via the above make run.
132 lines
3.6 KiB
C
132 lines
3.6 KiB
C
/* word_io.c -- word oriented I/O
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Copyright (C) 2007-2026 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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/* config.h must be included first. */
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#include <config.h>
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/* system headers. */
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#include <errno.h>
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#include <stdbool.h> /* for bool */
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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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/* gnulib headers. */
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#include <endian.h>
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#include "quotearg.h"
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/* find headers. */
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#include "system.h"
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#include "locatedb.h"
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enum { WORDBYTES=4 };
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static int
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decode_value (const unsigned char data[],
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int limit,
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GetwordEndianState *endian_state_flag,
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const char *filename)
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{
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int swapped;
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union
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{
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int ival; /* native representation */
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unsigned char data[WORDBYTES];
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} u;
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u.ival = 0;
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memcpy (&u.data, data, WORDBYTES);
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swapped = htobe32 (u.ival); /* byteswapped */
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if (*endian_state_flag == GetwordEndianStateInitial)
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{
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if (u.ival <= limit)
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{
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if (swapped > limit)
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{
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/* the native value is inside the limit and the
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* swapped value is not. We take this as proof
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* that we should be using the native byte order.
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*/
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*endian_state_flag = GetwordEndianStateNative;
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}
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return u.ival;
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}
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else
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{
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if (swapped <= limit)
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{
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/* Aha, now we know we have to byte-swap. */
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error (0, 0,
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_("WARNING: locate database %s was "
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"built with a different byte order"),
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quotearg_n_style (0, locale_quoting_style, filename));
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*endian_state_flag = GetwordEndianStateSwab;
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return swapped;
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}
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else
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{
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/* u.ival > limit and swapped > limit. For the moment, assume
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* native ordering.
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*/
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return u.ival;
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}
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}
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}
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else
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{
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/* We already know the byte order. */
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if (*endian_state_flag == GetwordEndianStateSwab)
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return swapped;
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else
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return u.ival;
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}
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}
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int
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getword (FILE *fp,
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const char *filename,
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size_t maxvalue,
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GetwordEndianState *endian_state_flag)
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{
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unsigned char data[4];
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size_t bytes_read;
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clearerr (fp);
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bytes_read = fread (data, WORDBYTES, 1, fp);
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if (bytes_read != 1)
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{
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const char * quoted_name = quotearg_n_style (0, locale_quoting_style,
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filename);
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/* Distinguish between a truncated database and an I/O error.
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* Either condition is fatal.
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*/
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if (feof (fp))
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error (EXIT_FAILURE, 0, _("unexpected EOF in %s"), quoted_name);
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else
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error (EXIT_FAILURE, errno,
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_("error reading a word from %s"), quoted_name);
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abort ();
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}
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else
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{
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return decode_value (data, maxvalue, endian_state_flag, filename);
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}
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}
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