search.h
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/*
* 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 __crlf_is_lf, 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 */