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