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 * SPDX-License-Identifier: LGPL-2.1+ 7 */ 8 9 /* 10 * Based on code from uClibc-0.9.30.3 11 * Extensions for use within U-Boot 12 * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de> 13 */ 14 15 #ifndef _SEARCH_H 16 #define _SEARCH_H 1 17 18 #include <stddef.h> 19 20 #define __set_errno(val) do { errno = val; } while (0) 21 22 enum env_op { 23 env_op_create, 24 env_op_delete, 25 env_op_overwrite, 26 }; 27 28 /* Action which shall be performed in the call the hsearch. */ 29 typedef enum { 30 FIND, 31 ENTER 32 } ACTION; 33 34 typedef struct entry { 35 const char *key; 36 char *data; 37 int (*callback)(const char *name, const char *value, enum env_op op, 38 int flags); 39 int flags; 40 } ENTRY; 41 42 /* Opaque type for internal use. */ 43 struct _ENTRY; 44 45 /* 46 * Family of hash table handling functions. The functions also 47 * have reentrant counterparts ending with _r. The non-reentrant 48 * functions all work on a signle internal hashing table. 49 */ 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 67 /* Create a new hashing table which will at most contain NEL elements. */ 68 extern int hcreate_r(size_t __nel, struct hsearch_data *__htab); 69 70 /* Destroy current internal hashing table. */ 71 extern void hdestroy_r(struct hsearch_data *__htab); 72 73 /* 74 * Search for entry matching ITEM.key in internal hash table. If 75 * ACTION is `FIND' return found entry or signal error by returning 76 * NULL. If ACTION is `ENTER' replace existing data (if any) with 77 * ITEM.data. 78 * */ 79 extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval, 80 struct hsearch_data *__htab, int __flag); 81 82 /* 83 * Search for an entry matching `MATCH'. Otherwise, Same semantics 84 * as hsearch_r(). 85 */ 86 extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval, 87 struct hsearch_data *__htab); 88 89 /* Search and delete entry matching ITEM.key in internal hash table. */ 90 extern int hdelete_r(const char *__key, struct hsearch_data *__htab, 91 int __flag); 92 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 /* 98 * nvars: length of vars array 99 * vars: array of strings (variable names) to import (nvars == 0 means all) 100 * do_apply: whether to call callback function to check the new argument, 101 * and possibly apply changes (false means accept everything) 102 */ 103 extern int himport_r(struct hsearch_data *__htab, 104 const char *__env, size_t __size, const char __sep, 105 int __flag, int __crlf_is_lf, int nvars, 106 char * const vars[]); 107 108 /* Walk the whole table calling the callback on each element */ 109 extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *)); 110 111 /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */ 112 #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ 113 #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ 114 #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ 115 #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */ 116 #define H_MATCH_KEY (1 << 4) /* search/grep key = variable names */ 117 #define H_MATCH_DATA (1 << 5) /* search/grep data = variable values */ 118 #define H_MATCH_BOTH (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both */ 119 #define H_MATCH_IDENT (1 << 6) /* search for indentical strings */ 120 #define H_MATCH_SUBSTR (1 << 7) /* search for substring matches */ 121 #define H_MATCH_REGEX (1 << 8) /* search for regular expression matches */ 122 #define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX) 123 124 #endif /* search.h */ 125