/* * Declarations for System V style searching functions. * Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc. * This file is part of the GNU C Library. * * SPDX-License-Identifier: LGPL-2.1+ */ /* * Based on code from uClibc-0.9.30.3 * Extensions for use within U-Boot * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de> */ #ifndef _SEARCH_H #define _SEARCH_H 1 #include <stddef.h> #define __set_errno(val) do { errno = val; } while (0) enum env_op { env_op_create, env_op_delete, env_op_overwrite, }; /* Action which shall be performed in the call the hsearch. */ typedef enum { FIND, ENTER } ACTION; typedef struct entry { const char *key; char *data; int (*callback)(const char *name, const char *value, enum env_op op, int flags); int flags; } ENTRY; /* Opaque type for internal use. */ struct _ENTRY; /* * Family of hash table handling functions. The functions also * have reentrant counterparts ending with _r. The non-reentrant * functions all work on a signle internal hashing table. */ /* Data type for reentrant functions. */ struct hsearch_data { struct _ENTRY *table; unsigned int size; unsigned int filled; /* * Callback function which will check whether the given change for variable * "item" to "newval" may be applied or not, and possibly apply such change. * When (flag & H_FORCE) is set, it shall not print out any error message and * shall force overwriting of write-once variables. .* Must return 0 for approval, 1 for denial. */ int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op, int flag); }; /* Create a new hashing table which will at most contain NEL elements. */ extern int hcreate_r(size_t __nel, struct hsearch_data *__htab); /* Destroy current internal hashing table. */ extern void hdestroy_r(struct hsearch_data *__htab); /* * Search for entry matching ITEM.key in internal hash table. If * ACTION is `FIND' return found entry or signal error by returning * NULL. If ACTION is `ENTER' replace existing data (if any) with * ITEM.data. * */ extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval, struct hsearch_data *__htab, int __flag); /* * Search for an entry matching `MATCH'. Otherwise, Same semantics * as hsearch_r(). */ extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval, struct hsearch_data *__htab); /* Search and delete entry matching ITEM.key in internal hash table. */ extern int hdelete_r(const char *__key, struct hsearch_data *__htab, int __flag); extern ssize_t hexport_r(struct hsearch_data *__htab, const char __sep, int __flag, char **__resp, size_t __size, int argc, char * const argv[]); /* * nvars: length of vars array * vars: array of strings (variable names) to import (nvars == 0 means all) * do_apply: whether to call callback function to check the new argument, * and possibly apply changes (false means accept everything) */ extern int himport_r(struct hsearch_data *__htab, const char *__env, size_t __size, const char __sep, int __flag, int nvars, char * const vars[]); /* Walk the whole table calling the callback on each element */ extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *)); /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */ #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */ #define H_MATCH_KEY (1 << 4) /* search/grep key = variable names */ #define H_MATCH_DATA (1 << 5) /* search/grep data = variable values */ #define H_MATCH_BOTH (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both */ #define H_MATCH_IDENT (1 << 6) /* search for indentical strings */ #define H_MATCH_SUBSTR (1 << 7) /* search for substring matches */ #define H_MATCH_REGEX (1 << 8) /* search for regular expression matches */ #define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX) #endif /* search.h */