The C and C++ Include Header Files

/usr/include/search.h


$ cat -n /usr/include/search.h

     1	/* Declarations for System V style searching functions.
     2	   Copyright (C) 1995-2024 Free Software Foundation, Inc.
     3	   This file is part of the GNU C Library.
     4	
     5	   The GNU C Library is free software; you can redistribute it and/or
     6	   modify it under the terms of the GNU Lesser General Public
     7	   License as published by the Free Software Foundation; either
     8	   version 2.1 of the License, or (at your option) any later version.
     9	
    10	   The GNU C Library is distributed in the hope that it will be useful,
    11	   but WITHOUT ANY WARRANTY; without even the implied warranty of
    12	   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13	   Lesser General Public License for more details.
    14	
    15	   You should have received a copy of the GNU Lesser General Public
    16	   License along with the GNU C Library; if not, see
    17	   <https://www.gnu.org/licenses/>.  */
    18	
    19	#ifndef _SEARCH_H
    20	#define	_SEARCH_H 1
    21	
    22	#include <features.h>
    23	
    24	#define __need_size_t
    25	#include <stddef.h>
    26	
    27	__BEGIN_DECLS
    28	
    29	#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
    30	/* Prototype structure for a linked-list data structure.
    31	   This is the type used by the `insque' and `remque' functions.  */
    32	
    33	# ifdef __USE_GNU
    34	struct qelem
    35	  {
    36	    struct qelem *q_forw;
    37	    struct qelem *q_back;
    38	    char q_data[1];
    39	  };
    40	# endif
    41	
    42	
    43	/* Insert ELEM into a doubly-linked list, after PREV.  */
    44	extern void insque (void *__elem, void *__prev) __THROW;
    45	
    46	/* Unlink ELEM from the doubly-linked list that it is in.  */
    47	extern void remque (void *__elem) __THROW;
    48	#endif
    49	
    50	
    51	/* For use with hsearch(3).  */
    52	#ifndef __COMPAR_FN_T
    53	# define __COMPAR_FN_T
    54	typedef int (*__compar_fn_t) (const void *, const void *);
    55	
    56	# ifdef	__USE_GNU
    57	typedef __compar_fn_t comparison_fn_t;
    58	# endif
    59	#endif
    60	
    61	/* Action which shall be performed in the call the hsearch.  */
    62	typedef enum
    63	  {
    64	    FIND,
    65	    ENTER
    66	  }
    67	ACTION;
    68	
    69	typedef struct entry
    70	  {
    71	    char *key;
    72	    void *data;
    73	  }
    74	ENTRY;
    75	
    76	/* Opaque type for internal use.  */
    77	struct _ENTRY;
    78	
    79	/* Family of hash table handling functions.  The functions also
    80	   have reentrant counterparts ending with _r.  The non-reentrant
    81	   functions all work on a single internal hashing table.  */
    82	
    83	/* Search for entry matching ITEM.key in internal hash table.  If
    84	   ACTION is `FIND' return found entry or signal error by returning
    85	   NULL.  If ACTION is `ENTER' replace existing data (if any) with
    86	   ITEM.data.  */
    87	extern ENTRY *hsearch (ENTRY __item, ACTION __action) __THROW;
    88	
    89	/* Create a new hashing table which will at most contain NEL elements.  */
    90	extern int hcreate (size_t __nel) __THROW;
    91	
    92	/* Destroy current internal hashing table.  */
    93	extern void hdestroy (void) __THROW;
    94	
    95	#ifdef __USE_GNU
    96	/* Data type for reentrant functions.  */
    97	struct hsearch_data
    98	  {
    99	    struct _ENTRY *table;
   100	    unsigned int size;
   101	    unsigned int filled;
   102	  };
   103	
   104	/* Reentrant versions which can handle multiple hashing tables at the
   105	   same time.  */
   106	extern int hsearch_r (ENTRY __item, ACTION __action, ENTRY **__retval,
   107			      struct hsearch_data *__htab) __THROW;
   108	extern int hcreate_r (size_t __nel, struct hsearch_data *__htab) __THROW;
   109	extern void hdestroy_r (struct hsearch_data *__htab) __THROW;
   110	#endif
   111	
   112	
   113	/* The tsearch routines are very interesting. They make many
   114	   assumptions about the compiler.  It assumes that the first field
   115	   in node must be the "key" field, which points to the datum.
   116	   Everything depends on that.  */
   117	/* For tsearch */
   118	typedef enum
   119	{
   120	  preorder,
   121	  postorder,
   122	  endorder,
   123	  leaf
   124	}
   125	VISIT;
   126	
   127	/* Search for an entry matching the given KEY in the tree pointed to
   128	   by *ROOTP and insert a new element if not found.  */
   129	extern void *tsearch (const void *__key, void **__rootp,
   130			      __compar_fn_t __compar);
   131	
   132	/* Search for an entry matching the given KEY in the tree pointed to
   133	   by *ROOTP.  If no matching entry is available return NULL.  */
   134	extern void *tfind (const void *__key, void *const *__rootp,
   135			    __compar_fn_t __compar);
   136	
   137	/* Remove the element matching KEY from the tree pointed to by *ROOTP.  */
   138	extern void *tdelete (const void *__restrict __key,
   139			      void **__restrict __rootp,
   140			      __compar_fn_t __compar);
   141	
   142	#ifndef __ACTION_FN_T
   143	# define __ACTION_FN_T
   144	typedef void (*__action_fn_t) (const void *__nodep, VISIT __value,
   145				       int __level);
   146	#endif
   147	
   148	/* Walk through the whole tree and call the ACTION callback for every node
   149	   or leaf.  */
   150	extern void twalk (const void *__root, __action_fn_t __action);
   151	
   152	#ifdef __USE_GNU
   153	/* Like twalk, but pass down a closure parameter instead of the
   154	   level.  */
   155	extern void twalk_r (const void *__root,
   156			     void (*) (const void *__nodep, VISIT __value,
   157				       void *__closure),
   158			     void *__closure);
   159	
   160	/* Callback type for function to free a tree node.  If the keys are atomic
   161	   data this function should do nothing.  */
   162	typedef void (*__free_fn_t) (void *__nodep);
   163	
   164	/* Destroy the whole tree, call FREEFCT for each node or leaf.  */
   165	extern void tdestroy (void *__root, __free_fn_t __freefct);
   166	#endif
   167	
   168	
   169	/* Perform linear search for KEY by comparing by COMPAR in an array
   170	   [BASE,BASE+NMEMB*SIZE).  */
   171	extern void *lfind (const void *__key, const void *__base,
   172			    size_t *__nmemb, size_t __size, __compar_fn_t __compar);
   173	
   174	/* Perform linear search for KEY by comparing by COMPAR function in
   175	   array [BASE,BASE+NMEMB*SIZE) and insert entry if not found.  */
   176	extern void *lsearch (const void *__key, void *__base,
   177			      size_t *__nmemb, size_t __size, __compar_fn_t __compar);
   178	
   179	__END_DECLS
   180	
   181	#endif /* search.h */