Copyright (C) 2010-2018 Victor C. Salas nmagko@gmail.com
This program is free software; you can redistribute it and/or modify it under the terms of the GNU Public License as published by the Free Software Foundation; either version 3 of the license or (in your opinion) any later version.
The Micro Database Manager Library is a set of facilities and tools to handle Hash and Recno Databases. It includes hash and recno programs to handle databases in shell and a library for C developers.
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make
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gcc
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gdbm [1]
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hadb: Hash Database program to insert, update, and list hashes.
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hadbdel: Hash Database program to remove hashes.
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redb: Recno Database program to insert, update, and list records.
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redbdel: Recno Database program to remove database records.
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udbm.h: Header files that have interfaces for C programming.
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libudbm.so: Library sharing objects.
Go to the libudbm source folder and run as root:
make
make install
Go to the libudbm source folder and run as root:
make uninstall
make clean
The following functions have been implemented from scratch inside libudbm as a replacement for Berkeley DB to simplify programming ports to gdbm. The functions prototype is defined under udbm.h header file.
int db185_close (DB *);
int db185_del (const DB *, const DBT *, u_int);
int db185_get (const DB *, const DBT *, DBT *, u_int);
int db185_put (const DB *, DBT *, const DBT *, u_int);
int db185_seq (const DB *, DBT *, DBT *, u_int);
int db185_sync (const DB *, u_int);
int db185_fd (const DB *);
DB *dbopen (const char *, int, int, DBTYPE, const void *);
#define __db185_open dbopen
If your program uses Berkeley DB with any of the above functions you can migrate to gdbm by exchanging db_185.h header file to udbm.h file.
For compatibility the udbm.h file includes the DBT' structure (mapped to datum' structure) and `DB' structure.
DB *hdbopen(const char *filename);
It opens _filename_, creates a DB descriptor, and returns it.
int hdbclose(DB *dsc);
This function is used to free a _dsc_ DB descriptor.
int hdbsync(DB *dsc);
Sync memory. Flush to disk.
int hdbseq(DB *dsc, char **key, char **value);
Get hashes sequentially. You have to free the pointer of _key_ name
and its _value_ when they are not used anymore and if the returned
value of the function is 0.
int hdbdel(DB *dsc, const char *key);
Get rid of the _key_ from _dsc_ DB descriptor.
char *hdbget(DB *dsc, const char *key);
It returns the value of the _key_ from _dsc_ DB descriptor. You have
to free the returned pointer when it is not used anymore.
int hdbput(DB *dsc, const char *key, const char *value);
Overwrites or sets a new _key_ entry with provided _value_.
DB *rdbopen(const char *filename);
It opens _filename_, creates a DB descriptor, and returns it.
int rdbclose(DB *dsc);
This function is used to free a _dsc_ DB descriptor.
int rdbsync(DB *dsc);
Sync memory. Flush to disk.
int rdbseq(DB *dsc, char **rNum, char **lnValue);
Get rows sequentially. You have to free row number _rNum_ and line
content _lnValue_ pointers when they are not used anymore and if the
returned value of the function is 0.
int rdbdel(DB *dsc, const char *rNum);
Get rid of the row number _rNum_ from _dsc_ DB descriptor.
char *rdbget(DB *dsc, const char *rNum);
It returns the line content of the row number _rNum_ from _dsc_ DB
descriptor. You have to free the returned pointer when it is not used
anymore.
int rdbput(DB *dsc, const char *lnValue);
Insert a new row with line content _lnValue_ to _dsc_ DB descriptor.
int rdbheader(DB *dsc, const char *fieldnames);
Set header line or field names to _dsc_ DB descriptor with
_filednames_. You can use commas or another character that you prefer
to separate field names but remember the post-processing of the header
line is up to you i.e. splitting _fieldnames_.
hadb [key] [value]
It's a facility to insert a key-value pair in hash DB.
hadb database.hdb
Show the content of all hashes. Be aware that hadb is going to show everything even if hash DB is huge.
hadb database.hdb five
Show `five' key content.
hadb database.hdb four "it is an integer number"
Insert/Update the `four' key with "it is an integer number" as a value.
hadbdel
It's a facility to get rid of key-value pairs from hash DB.
hadbdel database.hdb four
Get rid of four keys and their value.
redb [[i|f] <recno|value>]
It's a facility to insert lines in recno DB and show its content.
redb database.rdb
Show all recno database content. Be aware that redb is going to show everything even if recno DB is huge.
redb database.rdb 5
Show the content of row number 5.
redb database.rdb recno
Show rows inserted count number (recno is a reserved word).
redb database.rdb i "whatever content do you want"
Insert a new database row with "whatever content you want".
redb database.rdb f "whatever"
Insert/Update header line with "whatever" field names.
redb database.rdb fields
Show header line (fields is a reserved word).
redbdel
It's a facility to get rid of a row from recno DB. After the row is removed the program reconstructs row numbers and can be slow if recno DB is huge.
redbdel database.rdb 2
Get rid of four keys and their value.
[1] gdbm at http://www.nongnu.org/
P.S.
Write me an email if you have any questions, please use American English or Spanish, I will reply to you when I get time.
Victor C Salas (aka nmagko)
Copyright (C) 2010-2018 Victor C Salas
Permission is granted to copy, distribute, and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License."