search.h 4.3 KB

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  1. /*
  2. * Declarations for System V style searching functions.
  3. * Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc.
  4. * This file is part of the GNU C Library.
  5. *
  6. * The GNU C Library is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU Lesser General Public
  8. * License as published by the Free Software Foundation; either
  9. * version 2.1 of the License, or (at your option) any later version.
  10. *
  11. * The GNU C Library is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14. * Lesser General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU Lesser General Public
  17. * License along with the GNU C Library; if not, write to the Free
  18. * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19. * 02111-1307 USA.
  20. */
  21. /*
  22. * Based on code from uClibc-0.9.30.3
  23. * Extensions for use within U-Boot
  24. * Copyright (C) 2010 Wolfgang Denk <wd@denx.de>
  25. */
  26. #ifndef _SEARCH_H
  27. #define _SEARCH_H 1
  28. #include <stddef.h>
  29. #define __set_errno(val) do { errno = val; } while (0)
  30. enum env_op {
  31. env_op_create,
  32. env_op_delete,
  33. env_op_overwrite,
  34. };
  35. /* Action which shall be performed in the call the hsearch. */
  36. typedef enum {
  37. FIND,
  38. ENTER
  39. } ACTION;
  40. typedef struct entry {
  41. const char *key;
  42. char *data;
  43. } ENTRY;
  44. /* Opaque type for internal use. */
  45. struct _ENTRY;
  46. /*
  47. * Family of hash table handling functions. The functions also
  48. * have reentrant counterparts ending with _r. The non-reentrant
  49. * functions all work on a signle internal hashing table.
  50. */
  51. /* Data type for reentrant functions. */
  52. struct hsearch_data {
  53. struct _ENTRY *table;
  54. unsigned int size;
  55. unsigned int filled;
  56. /*
  57. * Callback function which will check whether the given change for variable
  58. * "item" to "newval" may be applied or not, and possibly apply such change.
  59. * When (flag & H_FORCE) is set, it shall not print out any error message and
  60. * shall force overwriting of write-once variables.
  61. .* Must return 0 for approval, 1 for denial.
  62. */
  63. int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op,
  64. int flag);
  65. };
  66. /* Create a new hashing table which will at most contain NEL elements. */
  67. extern int hcreate_r(size_t __nel, struct hsearch_data *__htab);
  68. /* Destroy current internal hashing table. */
  69. extern void hdestroy_r(struct hsearch_data *__htab);
  70. /*
  71. * Search for entry matching ITEM.key in internal hash table. If
  72. * ACTION is `FIND' return found entry or signal error by returning
  73. * NULL. If ACTION is `ENTER' replace existing data (if any) with
  74. * ITEM.data.
  75. * */
  76. extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval,
  77. struct hsearch_data *__htab, int __flag);
  78. /*
  79. * Search for an entry matching `MATCH'. Otherwise, Same semantics
  80. * as hsearch_r().
  81. */
  82. extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval,
  83. struct hsearch_data *__htab);
  84. /*
  85. * Search for an entry whose key or data contains `MATCH'. Otherwise,
  86. * Same semantics as hsearch_r().
  87. */
  88. extern int hstrstr_r(const char *__match, int __last_idx, ENTRY ** __retval,
  89. struct hsearch_data *__htab);
  90. /* Search and delete entry matching ITEM.key in internal hash table. */
  91. extern int hdelete_r(const char *__key, struct hsearch_data *__htab,
  92. int __flag);
  93. extern ssize_t hexport_r(struct hsearch_data *__htab,
  94. const char __sep, int __flag, char **__resp, size_t __size,
  95. int argc, char * const argv[]);
  96. /*
  97. * nvars: length of vars array
  98. * vars: array of strings (variable names) to import (nvars == 0 means all)
  99. * do_apply: whether to call callback function to check the new argument,
  100. * and possibly apply changes (false means accept everything)
  101. */
  102. extern int himport_r(struct hsearch_data *__htab,
  103. const char *__env, size_t __size, const char __sep,
  104. int __flag, int nvars, char * const vars[]);
  105. /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */
  106. #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */
  107. #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */
  108. #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */
  109. #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */
  110. #endif /* search.h */