search.h 4.1 KB

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  1. /* SPDX-License-Identifier: LGPL-2.1+ */
  2. /*
  3. * Declarations for System V style searching functions.
  4. * Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc.
  5. * This file is part of the GNU C Library.
  6. */
  7. /*
  8. * Based on code from uClibc-0.9.30.3
  9. * Extensions for use within U-Boot
  10. * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de>
  11. */
  12. #ifndef _SEARCH_H_
  13. #define _SEARCH_H_
  14. #include <stddef.h>
  15. #define __set_errno(val) do { errno = val; } while (0)
  16. enum env_op {
  17. env_op_create,
  18. env_op_delete,
  19. env_op_overwrite,
  20. };
  21. /* Action which shall be performed in the call to hsearch. */
  22. typedef enum {
  23. FIND,
  24. ENTER
  25. } ACTION;
  26. typedef struct entry {
  27. const char *key;
  28. char *data;
  29. int (*callback)(const char *name, const char *value, enum env_op op,
  30. int flags);
  31. int flags;
  32. } ENTRY;
  33. /* Opaque type for internal use. */
  34. struct _ENTRY;
  35. /*
  36. * Family of hash table handling functions. The functions also
  37. * have reentrant counterparts ending with _r. The non-reentrant
  38. * functions all work on a single internal hash table.
  39. */
  40. /* Data type for reentrant functions. */
  41. struct hsearch_data {
  42. struct _ENTRY *table;
  43. unsigned int size;
  44. unsigned int filled;
  45. /*
  46. * Callback function which will check whether the given change for variable
  47. * "__item" to "newval" may be applied or not, and possibly apply such change.
  48. * When (flag & H_FORCE) is set, it shall not print out any error message and
  49. * shall force overwriting of write-once variables.
  50. * Must return 0 for approval, 1 for denial.
  51. */
  52. int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op,
  53. int flag);
  54. };
  55. /* Create a new hash table which will contain at most "__nel" elements. */
  56. extern int hcreate_r(size_t __nel, struct hsearch_data *__htab);
  57. /* Destroy current internal hash table. */
  58. extern void hdestroy_r(struct hsearch_data *__htab);
  59. /*
  60. * Search for entry matching __item.key in internal hash table. If
  61. * ACTION is `FIND' return found entry or signal error by returning
  62. * NULL. If ACTION is `ENTER' replace existing data (if any) with
  63. * __item.data.
  64. * */
  65. extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval,
  66. struct hsearch_data *__htab, int __flag);
  67. /*
  68. * Search for an entry matching "__match". Otherwise, Same semantics
  69. * as hsearch_r().
  70. */
  71. extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval,
  72. struct hsearch_data *__htab);
  73. /* Search and delete entry matching "__key" in internal hash table. */
  74. extern int hdelete_r(const char *__key, struct hsearch_data *__htab,
  75. int __flag);
  76. extern ssize_t hexport_r(struct hsearch_data *__htab,
  77. const char __sep, int __flag, char **__resp, size_t __size,
  78. int argc, char * const argv[]);
  79. /*
  80. * nvars: length of vars array
  81. * vars: array of strings (variable names) to import (nvars == 0 means all)
  82. */
  83. extern int himport_r(struct hsearch_data *__htab,
  84. const char *__env, size_t __size, const char __sep,
  85. int __flag, int __crlf_is_lf, int nvars,
  86. char * const vars[]);
  87. /* Walk the whole table calling the callback on each element */
  88. extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *));
  89. /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */
  90. #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */
  91. #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */
  92. #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */
  93. #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */
  94. #define H_MATCH_KEY (1 << 4) /* search/grep key = variable names */
  95. #define H_MATCH_DATA (1 << 5) /* search/grep data = variable values */
  96. #define H_MATCH_BOTH (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both */
  97. #define H_MATCH_IDENT (1 << 6) /* search for indentical strings */
  98. #define H_MATCH_SUBSTR (1 << 7) /* search for substring matches */
  99. #define H_MATCH_REGEX (1 << 8) /* search for regular expression matches */
  100. #define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX)
  101. #define H_PROGRAMMATIC (1 << 9) /* indicate that an import is from env_set() */
  102. #define H_ORIGIN_FLAGS (H_INTERACTIVE | H_PROGRAMMATIC)
  103. #endif /* _SEARCH_H_ */