53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
/* Copyright (C) 1992-2013 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <string.h>
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#include <stdlib.h>
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#include <time.h>
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#include <unistd.h>
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char *
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strfry (char *string)
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{
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static int init;
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static struct random_data rdata;
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if (!init)
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{
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static char state[32];
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rdata.state = NULL;
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__initstate_r (time ((time_t *) NULL) ^ getpid (),
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state, sizeof (state), &rdata);
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init = 1;
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}
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size_t len = strlen (string);
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if (len > 0)
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for (size_t i = 0; i < len - 1; ++i)
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{
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int32_t j;
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__random_r (&rdata, &j);
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j = j % (len - i) + i;
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char c = string[i];
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string[i] = string[j];
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string[j] = c;
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}
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return string;
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}
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