diff options
Diffstat (limited to 'REORG.TODO/string/strfry.c')
-rw-r--r-- | REORG.TODO/string/strfry.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/REORG.TODO/string/strfry.c b/REORG.TODO/string/strfry.c new file mode 100644 index 0000000000..9d1bd88d4d --- /dev/null +++ b/REORG.TODO/string/strfry.c @@ -0,0 +1,52 @@ +/* Copyright (C) 1992-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <string.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> + +char * +strfry (char *string) +{ + static int init; + static struct random_data rdata; + + if (!init) + { + static char state[32]; + rdata.state = NULL; + __initstate_r (time ((time_t *) NULL) ^ getpid (), + state, sizeof (state), &rdata); + init = 1; + } + + size_t len = strlen (string); + if (len > 0) + for (size_t i = 0; i < len - 1; ++i) + { + int32_t j; + __random_r (&rdata, &j); + j = j % (len - i) + i; + + char c = string[i]; + string[i] = string[j]; + string[j] = c; + } + + return string; +} |