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 /* 23 * Based on code from uClibc-0.9.30.3 24 * Extensions for use within U-Boot 25 * Copyright (C) 2010 Wolfgang Denk <wd@denx.de> 26 */ 27 28 #ifndef _SEARCH_H 29 #define _SEARCH_H 1 30 31 #include <stddef.h> 32 33 #define __set_errno(val) do { errno = val; } while (0) 34 35 enum env_op { 36 env_op_create, 37 env_op_delete, 38 env_op_overwrite, 39 }; 40 41 /* Action which shall be performed in the call the hsearch. */ 42 typedef enum { 43 FIND, 44 ENTER 45 } ACTION; 46 47 typedef struct entry { 48 const char *key; 49 char *data; 50 } ENTRY; 51 52 /* Opaque type for internal use. */ 53 struct _ENTRY; 54 55 /* 56 * Family of hash table handling functions. The functions also 57 * have reentrant counterparts ending with _r. The non-reentrant 58 * functions all work on a signle internal hashing table. 59 */ 60 61 /* Data type for reentrant functions. */ 62 struct hsearch_data { 63 struct _ENTRY *table; 64 unsigned int size; 65 unsigned int filled; 66 /* 67 * Callback function which will check whether the given change for variable 68 * "item" to "newval" may be applied or not, and possibly apply such change. 69 * When (flag & H_FORCE) is set, it shall not print out any error message and 70 * shall force overwriting of write-once variables. 71 .* Must return 0 for approval, 1 for denial. 72 */ 73 int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op, 74 int flag); 75 }; 76 77 /* Create a new hashing table which will at most contain NEL elements. */ 78 extern int hcreate_r(size_t __nel, struct hsearch_data *__htab); 79 80 /* Destroy current internal hashing table. */ 81 extern void hdestroy_r(struct hsearch_data *__htab); 82 83 /* 84 * Search for entry matching ITEM.key in internal hash table. If 85 * ACTION is `FIND' return found entry or signal error by returning 86 * NULL. If ACTION is `ENTER' replace existing data (if any) with 87 * ITEM.data. 88 * */ 89 extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval, 90 struct hsearch_data *__htab, int __flag); 91 92 /* 93 * Search for an entry matching `MATCH'. Otherwise, Same semantics 94 * as hsearch_r(). 95 */ 96 extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval, 97 struct hsearch_data *__htab); 98 /* 99 * Search for an entry whose key or data contains `MATCH'. Otherwise, 100 * Same semantics as hsearch_r(). 101 */ 102 extern int hstrstr_r(const char *__match, int __last_idx, ENTRY ** __retval, 103 struct hsearch_data *__htab); 104 105 /* Search and delete entry matching ITEM.key in internal hash table. */ 106 extern int hdelete_r(const char *__key, struct hsearch_data *__htab, 107 int __flag); 108 109 extern ssize_t hexport_r(struct hsearch_data *__htab, 110 const char __sep, char **__resp, size_t __size, 111 int argc, char * const argv[]); 112 113 /* 114 * nvars: length of vars array 115 * vars: array of strings (variable names) to import (nvars == 0 means all) 116 * do_apply: whether to call callback function to check the new argument, 117 * and possibly apply changes (false means accept everything) 118 */ 119 extern int himport_r(struct hsearch_data *__htab, 120 const char *__env, size_t __size, const char __sep, 121 int __flag, int nvars, char * const vars[]); 122 123 /* Flags for himport_r(), hdelete_r(), and hsearch_r() */ 124 #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ 125 #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ 126 #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ 127 128 #endif /* search.h */ 129