blob: 9701efb2dfe37c51d462ae85bc04648d49192f44
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 | * SPDX-License-Identifier: LGPL-2.1+ |
7 | */ |
8 | |
9 | /* |
10 | * Based on code from uClibc-0.9.30.3 |
11 | * Extensions for use within U-Boot |
12 | * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de> |
13 | */ |
14 | |
15 | #ifndef _SEARCH_H |
16 | #define _SEARCH_H 1 |
17 | |
18 | #include <stddef.h> |
19 | |
20 | #define __set_errno(val) do { errno = val; } while (0) |
21 | |
22 | enum env_op { |
23 | env_op_create, |
24 | env_op_delete, |
25 | env_op_overwrite, |
26 | }; |
27 | |
28 | /* Action which shall be performed in the call the hsearch. */ |
29 | typedef enum { |
30 | FIND, |
31 | ENTER |
32 | } ACTION; |
33 | |
34 | typedef struct entry { |
35 | const char *key; |
36 | char *data; |
37 | int (*callback)(const char *name, const char *value, enum env_op op, |
38 | int flags); |
39 | int flags; |
40 | } ENTRY; |
41 | |
42 | /* Opaque type for internal use. */ |
43 | struct _ENTRY; |
44 | |
45 | /* |
46 | * Family of hash table handling functions. The functions also |
47 | * have reentrant counterparts ending with _r. The non-reentrant |
48 | * functions all work on a signle internal hashing table. |
49 | */ |
50 | |
51 | /* Data type for reentrant functions. */ |
52 | struct hsearch_data { |
53 | struct _ENTRY *table; |
54 | unsigned int size; |
55 | unsigned int filled; |
56 | /* |
57 | * Callback function which will check whether the given change for variable |
58 | * "item" to "newval" may be applied or not, and possibly apply such change. |
59 | * When (flag & H_FORCE) is set, it shall not print out any error message and |
60 | * shall force overwriting of write-once variables. |
61 | .* Must return 0 for approval, 1 for denial. |
62 | */ |
63 | int (*change_ok)(const ENTRY *__item, const char *newval, enum env_op, |
64 | int flag); |
65 | }; |
66 | |
67 | /* Create a new hashing table which will at most contain NEL elements. */ |
68 | extern int hcreate_r(size_t __nel, struct hsearch_data *__htab); |
69 | |
70 | /* Destroy current internal hashing table. */ |
71 | extern void hdestroy_r(struct hsearch_data *__htab); |
72 | |
73 | /* |
74 | * Search for entry matching ITEM.key in internal hash table. If |
75 | * ACTION is `FIND' return found entry or signal error by returning |
76 | * NULL. If ACTION is `ENTER' replace existing data (if any) with |
77 | * ITEM.data. |
78 | * */ |
79 | extern int hsearch_r(ENTRY __item, ACTION __action, ENTRY ** __retval, |
80 | struct hsearch_data *__htab, int __flag); |
81 | |
82 | /* |
83 | * Search for an entry matching `MATCH'. Otherwise, Same semantics |
84 | * as hsearch_r(). |
85 | */ |
86 | extern int hmatch_r(const char *__match, int __last_idx, ENTRY ** __retval, |
87 | struct hsearch_data *__htab); |
88 | |
89 | /* Search and delete entry matching ITEM.key in internal hash table. */ |
90 | extern int hdelete_r(const char *__key, struct hsearch_data *__htab, |
91 | int __flag); |
92 | |
93 | extern ssize_t hexport_r(struct hsearch_data *__htab, |
94 | const char __sep, int __flag, char **__resp, size_t __size, |
95 | int argc, char * const argv[]); |
96 | |
97 | /* |
98 | * nvars: length of vars array |
99 | * vars: array of strings (variable names) to import (nvars == 0 means all) |
100 | * do_apply: whether to call callback function to check the new argument, |
101 | * and possibly apply changes (false means accept everything) |
102 | */ |
103 | extern int himport_r(struct hsearch_data *__htab, |
104 | const char *__env, size_t __size, const char __sep, |
105 | int __flag, int __crlf_is_lf, int nvars, |
106 | char * const vars[]); |
107 | |
108 | /* Walk the whole table calling the callback on each element */ |
109 | extern int hwalk_r(struct hsearch_data *__htab, int (*callback)(ENTRY *)); |
110 | |
111 | /* Flags for himport_r(), hexport_r(), hdelete_r(), and hsearch_r() */ |
112 | #define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */ |
113 | #define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */ |
114 | #define H_INTERACTIVE (1 << 2) /* indicate that an import is user directed */ |
115 | #define H_HIDE_DOT (1 << 3) /* don't print env vars that begin with '.' */ |
116 | #define H_MATCH_KEY (1 << 4) /* search/grep key = variable names */ |
117 | #define H_MATCH_DATA (1 << 5) /* search/grep data = variable values */ |
118 | #define H_MATCH_BOTH (H_MATCH_KEY | H_MATCH_DATA) /* search/grep both */ |
119 | #define H_MATCH_IDENT (1 << 6) /* search for indentical strings */ |
120 | #define H_MATCH_SUBSTR (1 << 7) /* search for substring matches */ |
121 | #define H_MATCH_REGEX (1 << 8) /* search for regular expression matches */ |
122 | #define H_MATCH_METHOD (H_MATCH_IDENT | H_MATCH_SUBSTR | H_MATCH_REGEX) |
123 | |
124 | #endif /* search.h */ |
125 |