search.h
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/* SPDX-License-Identifier: LGPL-2.1+ */
/*
* 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.
*/
/*
* 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_
#include <env.h>
#include <stddef.h>
#define set_errno(val) do { errno = val; } while (0)
/* enum env_action: action which shall be performed in the call to hsearch */
enum env_action {
ENV_FIND,
ENV_ENTER,
};
/** struct env_entry - An entry in the environment hashtable */
struct env_entry {
const char *key;
char *data;
int (*callback)(const char *name, const char *value, enum env_op op,
int flags);
int flags;
};
/*
* Family of hash table handling functions. The functions also
* have reentrant counterparts ending with _r. The non-reentrant
* functions all work on a single internal hash table.
*/
/* Data type for reentrant functions. */
struct hsearch_data {
struct env_entry_node *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 struct env_entry *item, const char *newval,
enum env_op, int flag);
};
/* Create a new hash table which will contain at most "nel" elements. */
int hcreate_r(size_t nel, struct hsearch_data *htab);
/* Destroy current internal hash table. */
void hdestroy_r(struct hsearch_data *htab);
/*
* Search for entry matching item.key in internal hash table. If
* action is `ENV_FIND' return found entry or signal error by returning
* NULL. If action is `ENV_ENTER' replace existing data (if any) with
* item.data.
* */
int hsearch_r(struct env_entry item, enum env_action action,
struct env_entry **retval, struct hsearch_data *htab, int flag);
/*
* Search for an entry matching "match". Otherwise, Same semantics
* as hsearch_r().
*/
int hmatch_r(const char *match, int last_idx, struct env_entry **retval,
struct hsearch_data *htab);
/* Search and delete entry matching "key" in internal hash table. */
int hdelete_r(const char *key, struct hsearch_data *htab, int flag);
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)
*/
int himport_r(struct hsearch_data *htab, const char *env, size_t size,
const char sep, int flag, int crlf_is_lf, int nvars,
char * const vars[]);
/* Walk the whole table calling the callback on each element */
int hwalk_r(struct hsearch_data *htab,
int (*callback)(struct env_entry *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)
#define H_PROGRAMMATIC (1 << 9) /* indicate that an import is from env_set() */
#define H_ORIGIN_FLAGS (H_INTERACTIVE | H_PROGRAMMATIC)
#endif /* _SEARCH_H_ */