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      1  1.6  andvar #	$NetBSD: README,v 1.6 2024/02/09 22:08:30 andvar Exp $
      2  1.2     cgd #	@(#)README	8.1 (Berkeley) 6/4/93
      3  1.1     cgd 
      4  1.1     cgd This package implements a superset of the hsearch and dbm/ndbm libraries.
      5  1.1     cgd 
      6  1.1     cgd Test Programs:
      7  1.1     cgd 	All test programs which need key/data pairs expect them entered
      8  1.1     cgd 	with key and data on separate lines
      9  1.1     cgd 
     10  1.1     cgd 	tcreat3.c	
     11  1.1     cgd 		Takes 
     12  1.1     cgd 			bucketsize (bsize), 
     13  1.1     cgd 			fill factor (ffactor), and
     14  1.1     cgd 			initial number of elements (nelem).  
     15  1.1     cgd 		Creates a hash table named hashtest containing the 
     16  1.1     cgd 		keys/data pairs entered from standard in.
     17  1.1     cgd 	thash4.c
     18  1.1     cgd 		Takes
     19  1.1     cgd 			bucketsize (bsize), 
     20  1.1     cgd 			fill factor (ffactor), 
     21  1.1     cgd 			initial number of elements (nelem)
     22  1.1     cgd 			bytes of cache (ncached), and
     23  1.1     cgd 			file from which to read data  (fname)
     24  1.1     cgd 		Creates a table from the key/data pairs on standard in and
     25  1.1     cgd 		then does a read of each key/data in fname
     26  1.1     cgd 	tdel.c
     27  1.1     cgd 		Takes
     28  1.1     cgd 			bucketsize (bsize), and
     29  1.1     cgd 			fill factor (ffactor).
     30  1.1     cgd 			file from which to read data (fname)
     31  1.1     cgd 		Reads each key/data pair from fname and deletes the
     32  1.1     cgd 		key from the hash table hashtest
     33  1.1     cgd 	tseq.c
     34  1.1     cgd 		Reads the key/data pairs in the file hashtest and writes them
     35  1.1     cgd 		to standard out.
     36  1.1     cgd 	tread2.c
     37  1.1     cgd 		Takes
     38  1.1     cgd 			butes of cache (ncached).
     39  1.1     cgd 		Reads key/data pairs from standard in and looks them up
     40  1.1     cgd 		in the file hashtest.
     41  1.1     cgd 	tverify.c
     42  1.1     cgd 		Reads key/data pairs from standard in, looks them up
     43  1.1     cgd 		in the file hashtest, and verifies that the data is
     44  1.1     cgd 		correct.
     45  1.1     cgd 
     46  1.1     cgd NOTES:
     47  1.1     cgd 
     48  1.2     cgd The man page ../man/db.3 explains the interface to the hashing system.
     49  1.1     cgd The file hash.ps is a postscript copy of a paper explaining
     50  1.1     cgd the history, implementation, and performance of the hash package.
     51  1.1     cgd 
     52  1.6  andvar "bugs" or idiosyncrasies
     53  1.1     cgd 
     54  1.1     cgd If you have a lot of overflows, it is possible to run out of overflow
     55  1.1     cgd pages.  Currently, this will cause a message to be printed on stderr.
     56  1.1     cgd Eventually, this will be indicated by a return error code.
     57  1.1     cgd 
     58  1.1     cgd If you are using the ndbm interface and exit without flushing or closing the
     59  1.1     cgd file, you may lose updates since the package buffers all writes.  Also,
     60  1.1     cgd the db interface only creates a single database file.  To avoid overwriting
     61  1.1     cgd the user's original file, the suffix ".db" is appended to the file name
     62  1.1     cgd passed to dbm_open.  Additionally, if your code "knows" about the historic
     63  1.1     cgd .dir and .pag files, it will break.  
     64  1.1     cgd 
     65  1.1     cgd There is a fundamental difference between this package and the old hsearch.
     66  1.1     cgd Hsearch requires the user to maintain the keys and data in the application's
     67  1.1     cgd allocated memory while hash takes care of all storage management.  The down
     68  1.1     cgd side is that the byte strings passed in the ENTRY structure must be null
     69  1.1     cgd terminated (both the keys and the data).
     70