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 int (*callback)(const char *name, const char *value, enum env_op op, 51 int flags); 52 int flags; 53 } ENTRY; 54 55 /* Opaque type for internal use. */ 56 struct _ENTRY; 57 58 /* 59 * Family of hash table handling functions. The functions also 60 * have reentrant counterparts ending with _r. The non-reentrant 61 * functions all work on a signle internal hashing table. 62 */ 63 64 /* Data type for reentrant functions. */ 65 struct hsearch_data { 66 struct _ENTRY *table; 67 unsigned int size; 68 unsigned int filled; 69 /* 70 * Callback function which will check whether the given change for variable 71 * "item" to "newval" may be applied or not, and possibly apply such change. 72 * When (flag & H_FORCE) is set, it shall not print out any error message and 73 * shall force overwriting of write-once variables. 74 .* Must return 0 for approval, 1 for denial. 75 */ 76 int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op, 77 int flag); 78 }; 79 80 /* Create a new hashing table which will at most contain NEL elements. */ 81 extern int hcreate_r(size_t __nel, struct hsearch_data *__htab); 82 83 /* Destroy current internal hashing table. */ 84 extern void hdestroy_r(struct hsearch_data *__htab); 85 86 /* 87 * Search for entry matching ITEM.key in internal hash table. If 88 * ACTION is `FIND' return found entry or signal error by returning 89 * NULL. If ACTION is `ENTER' replace existing data (if any) with 90 * ITEM.data. 91 * */ 92 extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval, 93 struct hsearch_data *__htab, int __flag); 94 95 /* 96 * Search for an entry matching `MATCH'. Otherwise, Same semantics 97 * as hsearch_r(). 98 */ 99 extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval, 100 struct hsearch_data *__htab); 101 /* 102 * Search for an entry whose key or data contains `MATCH'. Otherwise, 103 * Same semantics as hsearch_r(). 104 */ 105 extern int hstrstr_r(const char *__match, int __last_idx, ENTRY ** __retval, 106 struct hsearch_data *__htab); 107 108 /* Search and delete entry matching ITEM.key in internal hash table. */ 109 extern int hdelete_r(const char *__key, struct hsearch_data *__htab, 110 int __flag); 111 112 extern ssize_t hexport_r(struct hsearch_data *__htab, 113 const char __sep, int __flag, char **__resp, size_t __size, 114 int argc, char * const argv[]); 115 116 /* 117 * nvars: length of vars array 118 * vars: array of strings (variable names) to import (nvars == 0 means all) 119 * do_apply: whether to call callback function to check the new argument, 120 * and possibly apply changes (false means accept everything) 121 */ 122 extern int himport_r(struct hsearch_data *__htab, 123 const char *__env, size_t __size, const char __sep, 124 int __flag, int nvars, char * const vars[]); 125 126 /* Walk the whole table calling the callback on each element */ 127 extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *)); 128 129 /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */ 130 #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ 131 #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ 132 #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ 133 #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */ 134 135 #endif /* search.h */ 136