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 /* 9 * Based on code from uClibc-0.9.30.3 10 * Extensions for use within U-Boot 11 * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de> 12 */ 13 14 #ifndef _SEARCH_H_ 15 #define _SEARCH_H_ 16 17 #include <env.h> 18 #include <stddef.h> 19 20 #define set_errno(val) do { errno = val; } while (0) 21 22 /* enum env_action: action which shall be performed in the call to hsearch */ 23 enum env_action { 24 ENV_FIND, 25 ENV_ENTER, 26 }; 27 28 /** struct env_entry - An entry in the environment hashtable */ 29 struct env_entry { 30 const char *key; 31 char *data; 32 int (*callback)(const char *name, const char *value, enum env_op op, 33 int flags); 34 int flags; 35 }; 36 37 /* 38 * Family of hash table handling functions. The functions also 39 * have reentrant counterparts ending with _r. The non-reentrant 40 * functions all work on a single internal hash table. 41 */ 42 43 /* Data type for reentrant functions. */ 44 struct hsearch_data { 45 struct env_entry_node *table; 46 unsigned int size; 47 unsigned int filled; 48 /* 49 * Callback function which will check whether the given change for variable 50 * "item" to "newval" may be applied or not, and possibly apply such change. 51 * When (flag & H_FORCE) is set, it shall not print out any error message and 52 * shall force overwriting of write-once variables. 53 * Must return 0 for approval, 1 for denial. 54 */ 55 int (*change_ok)(const struct env_entry *item, const char *newval, 56 enum env_op, int flag); 57 }; 58 59 /* Create a new hash table which will contain at most "nel" elements. */ 60 int hcreate_r(size_t nel, struct hsearch_data *htab); 61 62 /* Destroy current internal hash table. */ 63 void hdestroy_r(struct hsearch_data *htab); 64 65 /* 66 * Search for entry matching item.key in internal hash table. If 67 * action is `ENV_FIND' return found entry or signal error by returning 68 * NULL. If action is `ENV_ENTER' replace existing data (if any) with 69 * item.data. 70 * */ 71 int hsearch_r(struct env_entry item, enum env_action action, 72 struct env_entry **retval, struct hsearch_data *htab, int flag); 73 74 /* 75 * Search for an entry matching "match". Otherwise, Same semantics 76 * as hsearch_r(). 77 */ 78 int hmatch_r(const char *match, int last_idx, struct env_entry **retval, 79 struct hsearch_data *htab); 80 81 /* Search and delete entry matching "key" in internal hash table. */ 82 int hdelete_r(const char *key, struct hsearch_data *htab, int flag); 83 84 ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag, 85 char **resp, size_t size, int argc, char * const argv[]); 86 87 /* 88 * nvars: length of vars array 89 * vars: array of strings (variable names) to import (nvars == 0 means all) 90 */ 91 int himport_r(struct hsearch_data *htab, const char *env, size_t size, 92 const char sep, int flag, int crlf_is_lf, int nvars, 93 char * const vars[]); 94 95 /* Walk the whole table calling the callback on each element */ 96 int hwalk_r(struct hsearch_data *htab, 97 int (*callback)(struct env_entry *entry)); 98 99 /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */ 100 #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ 101 #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ 102 #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ 103 #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */ 104 #define H_MATCH_KEY (1 << 4) /* search/grep key = variable names */ 105 #define H_MATCH_DATA (1 << 5) /* search/grep data = variable values */ 106 #define H_MATCH_BOTH (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both */ 107 #define H_MATCH_IDENT (1 << 6) /* search for indentical strings */ 108 #define H_MATCH_SUBSTR (1 << 7) /* search for substring matches */ 109 #define H_MATCH_REGEX (1 << 8) /* search for regular expression matches */ 110 #define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX) 111 #define H_PROGRAMMATIC (1 << 9) /* indicate that an import is from env_set() */ 112 #define H_ORIGIN_FLAGS (H_INTERACTIVE | H_PROGRAMMATIC) 113 114 #endif /* _SEARCH_H_ */ 115