

I am a fan of the previous incarnation of the PlugComputer so I was excited to see that Marvell have unveiled a new PlugComputer dubbed imaginatively "PlugComputer 3.0."
PlugComputer 3.0 Features:
Smaller sleeker design,
More powerful CPU - 2gz Armanda 300 CPU,
120GB 1.8-inch SATA hard drive,
Wifi,
Bluetooth,
10/100/1000 wired Ethernet,
USB 2.0.
512MB of RAM
512MB of Flash memory
I for one would like to see an additional Ethernet port added to increase application flexibility, for some applications where you are using clustered plugs or even for routing, having multiple Ethernet ports is a must.
Even without multiple ethernet ports, these low power consumption devices really could have a place in SME environments, replacing large cumbersome legacy hardware with compact Linux plug servers.
More information about the PlugComputer can be found here
The getUIComponentBitmapData method can create bitmapdata for a given IUIComponent. Pass any UIcomponent to get its respective bitmapdata.
public static function getUIComponentBitmapData(target:IUIComponent):BitmapData { var resultBitmapData:BitmapData = new BitmapData(target.width, target.height); var m:Matrix = new Matrix(); resultBitmapData.draw(target, m); return resultBitmapData; }
Now convert the bitmapdata to a jpeg bytearray.
private static function encodeToJPEG(data:BitmapData, quality:Number = 75):ByteArray { var encoder:JPGEncoder = new JPGEncoder(quality); return encoder.encode(data); }
Now encode the ByteArray into Base64.
public static function base64Encode(data:ByteArray):String { var encoder:Base64Encoder = new Base64Encoder(); encoder.encodeBytes(data); return encoder.flush(); }
Upload the base64 encoded ByteArray to the server.
public static uploadData():void { var url:String = "saveFile.php"; var urlRequest:URLRequest = new URLRequest(url); urlRequest.method = URLRequestMethod.POST; var urlLoader:URLLoader = new URLLoader(); var urlVariables:URLVariables = new URLVariables(); urlVariables.file = jpgEncodedFile; // as returned from base64Encode() urlLoader.data = urlVariables; urlLoader.load(urlRequest); }
The saveFile.php file on the server.
$input = $_POST['file']; $fp = fopen('filename.jpg', 'w'); fwrite($fp, base64_decode($input)); fclose($fp); ?>
If you have a live linux site that is running vmware virtual machines, you can pause the virtual machines when you want to perform a backup, I use acronis for linux which does incremental backups and you can specify a command to run before and after the backup, this allows backups to be performed at scheduled times daily without any intervention. In my examples below, the virtual machine i want to control is in /root/vmware/Recital/Recital.vmx
To pause the virtual machine on linux:
# vmrun pause /root/vmware/Recital/Recital.vmx
and then to unpause after the backup has completed:
# vmrun unpause /root/vmware/Recital/Recital.vmx
That is basicallty it, no need to attend the backup and it can be perfomed at a suitable time so no users are affected.
Incidentally, vmrun lets you startup a virtual machine at system startup too, without needing the GUI:
# vmrun start /root/vmware/Recital/Recital.vmx
Or alternatively stop it:
# vmrun stop /root/vmware/Recital/Recital.vmx
There are lots of other capabilities of this command, running applications inside the virtual machine etc etc. For full details just type vmrun in a terminal window.
This article looks at the range of client access mechanisms for Windows that can be used with the Recital C-ISAM Bridge and details bridge configuration and usage.
Overview
Just because the format of data is regarded as 'legacy' does not make that data in any way obsolete. Modern client interfaces can not only extend the life of long-term data, but also provide different ways to analyse and gain advantage from that data.
Recital Corporation provides a range of solutions to interface to Informix compliant C-ISAM data on Linux or UNIX from Windows clients.
.NET
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Fig 1: Recital Mirage .NET application accessing the C-ISAM Demo table.
Recital offers two alternative ways to access C-ISAM data using Microsoft .NET:
The Recital .NET Data Provider is a managed Data Provider written in C# that provides full compatibility with the Microsoft SQLserver and OLE DB data providers that ship with the .NET framework. It is fully integrated with the Visual Studio .NET IDE supporting data binding and automatic code generation using the form designer. The Recital .NET Data Provider works in conjunction with the Recital Database Server for Linux or UNIX to access C-ISAM data.
Recital Mirage .NET is a complete solution for migrating, developing and deploying 4GL database applications. Recital Mirage .NET works in conjunction with the Recital Mirage .NET Application Server for Linux or UNIX to access C-ISAM data.
JDBC
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Fig 2: Java™ Swing JTable accessing the C-ISAM Demo table via the Recital JDBC Driver.
The Recital JDBC Driver is an all Java Type 4 JDBC 3.0 Driver, allowing you to access C-ISAM data from Java applets and applications. The Recital JDBC Driver works in conjunction with the Recital Database Server for Linux or UNIX to access C-ISAM data.
ODBC
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Fig 3: Microsoft® Office Excel 2003 Pivot Chart and Pivot Table accessing the C-ISAM Demo table via the Recital ODBC Driver.
The Recital ODBC Driver is an ODBC 3.0 Driver, allowing you to access C-ISAM data from your preferred ODBC based Windows applications. You can develop your own applications in languages such as C++ or Visual Basic, manipulate the data in a spreadsheet package or word processor document and design charts, graphs and reports. The Recital ODBC Driver works in conjunction with the Recital Database Server for Linux or UNIX to access C-ISAM data.
Configuring the Recital C-ISAM Bridge
Data access is achieved through a C-ISAM Bridge. This requires the creation of an empty Recital table that has the same structure as the C-ISAM file and of a RecitalC-ISAM Bridge file.
On Linux and UNIX, Recital Terminal Developer and the Recital Database Server come complete with an example C-ISAM data file, C-ISAM index and Recital C-ISAM bridge that can be used for testing and as a template for configuring your own C-ISAM bridges. The Recital Database Server also includes a bridge creation ini file.
Step 1:
Create a Recital table with the same structure as the C-ISAM file. The fields/columns in the structure file must exactly match the data type and length of those in the C-ISAM file. The Recital table will have one byte more in total record length due to the Recital record deletion marker.
To create the table, use the SQL CREATE TABLE command or the Recital Terminal Developer CREATE worksurface. The SQL CREATE TABLE command can be called directly:
SQLExecDirect: In: hstmt = 0x00761BE8, szSqlStr = "CREATE TABLE cisamdemo.str (DD Char(4) DESCRIPTION "Dd...", cbSqlStr = -3 Return: SQL_SUCCESS=0
or be included in a 4GL program:
// createtab.prg CREATE TABLE cisamdemo.str; (DD Char(4) DESCRIPTION "Dd",; CONFIRM Char(6) DESCRIPTION "Confirm",; PROCDATE Char(6) DESCRIPTION "Procdate",; CONTROL Char(5) DESCRIPTION "Control",; DOLLARS Decimal(13,2) DESCRIPTION "Dollars",; DEALER Char(5) DESCRIPTION "Dealer",; TERRITORY Char(2) DESCRIPTION "Territory",; WOREP Char(12) DESCRIPTION "Worep",; CURRTRAN Char(3) DESCRIPTION "Currtran",; TRADDATE Char(6) DESCRIPTION "Traddate",; CITY Char(10) DESCRIPTION "City",; ACCOUNT Char(11) DESCRIPTION "Account",; PRETRAN Char(2) DESCRIPTION "Pretran",; AFSREP Char(14) DESCRIPTION "Afsrep",; REPKEY Char(9) DESCRIPTION "Repkey",; BRANCH Char(3) DESCRIPTION "Branch",; WODEALER Char(5) DESCRIPTION "Wodealer",; BANKCODE Char(2) DESCRIPTION "Bankcode",; COMMRATE Decimal(6,4) DESCRIPTION "Commrate",; NEWREP Char(1) DESCRIPTION "Newrep",; SETTLE Char(1) DESCRIPTION "Settle",; POSTDATE Char(6) DESCRIPTION "Postdate") if file("cisamdemo.str") return .T. else return .F. endif // end of createtab.prg
Server-side 4GL programs can be called by all clients, e.g. from a Java class with a JDBC connection:
//--------------------------------- //-- create_str.java -- //--------------------------------- import java.sql.*; import java.io.*; import Recital.sql.*; public class create_str { public static void main(String argv[]) { try { new RecitalDriver(); String url = "jdbc:Recital:" + "SERVERNAME=cisamserver;" + "DIRECTORY=/usr/recital/data/southwind;" + "USERNAME=user;" + "PASSWORD=password"; Connection con = DriverManager.getConnection(url, "user", "pass"); Statement stmt = con.createStatement(); CallableStatement sp = con.prepareCall("{call createtab}"); boolean res = sp.execute(); String outParam = sp.getString(1); System.out.println("Returned "+outParam); sp.close(); con.close(); } catch (Exception e) { System.out.flush(); System.err.flush(); DriverManager.println("Driver exception: " + e.getMessage()); e.printStackTrace(); } try { System.out.println("Press any key to continue..."); System.in.read(); } catch(IOException ie) { ; } } }
The table should be given a ‘.str’ file extension (rather than the default ‘.dbf’) to signify that this is a structure file only.
Please see the end of this article for information on matching Informix and Recital data types
Fig 4: Recital CREATE/MODIFY STRUCTURE worksurface for character mode table creation.
Step 2: Creating the Bridge File
If you have Recital installed on the server platform, the Bridge File can be created using the CREATE BRIDGE worksurface. The corresponding command to modify the bridge file is MODIFY BRIDGE <bridge file>. This is the cisamdemo.dbf bridge file in the CREATE/MODIFY BRIDGE WORKSURFACE:
> modify bridge cisamdemo.dbf
Fig 5: Recital CREATE BRIDGE/MODIFY BRIDGE worksurface for bridge creation.
For Recital Database Server clients, the Bridge File can be created using the Recital/SQL CREATE BRIDGE command:
Recital/SQL CREATE BRIDGE:
CREATE BRIDGE cisamdemo.dbf; TYPE "CISAM"; EXTERNAL "cisamdemo.dat"; METADATA "cisamdemo.str"; ALIAS "cisamdemo"
or:
CREATE BRIDGE cisamdemo.dbf; AS "type=CISAM;external=cisamdemo.dat;metadata=cisamdemo.str;alias=cisamdemo"
The examples above assume that the C-ISAM file, the bridge file and the Recital structure file are all in the current working directory. Full path information can be specified for the <externalname> and the <databasename>. For added flexibility, environment variables can be used to determine the path at the time the bridge is opened. Environment variables can be included for either or both the <externalname> and the <databasename>. A colon should be specified between the environment variable and the file name.
e.g.
CREATE BRIDGE cisamdemo.dbf; TYPE "CISAM"; EXTERNAL "DB_DATADIR:cisamdemo"; METADATA "DB_MIRAGE_PATH:cisamdemo.str"; ALIAS "cisamdemo"
Recital CREATE BRIDGE/MODIFY BRIDGE worksurface:
Fig 6: Recital CREATE BRIDGE/MODIFY BRIDGE worksurface - using environment variables.
Using the Bridge
The Bridge can now be used. To access the C-ISAM file, use the ‘alias’ specified in the Bridge definition.
SQL:
SELECT * FROM cisamdemo
Recital/4GL:
use cisamdemo
Indexes
The cisamdemo.dat file included in the Recital distributions for Linux and UNIX has three associated index keys in the cisamdemo.idx file:
Select area: 1 Database in use: cisamdemo Alias: cisamdemo Number of records: 4 Current record: 2 File Type: CISAM (C-ISAM) Master Index: [cisamdemo.idx key #1] Key: DD+CONFIRM+PROCDATE+CONTROL Type: Character Len: 21 (Unique) Index: [cisamdemo.idx key #2]
Key: DD+SUBSTR(CONFIRM,2,5)+TRADDATE+STR(DOLLARS,13,2) +CURRTRAN+ACCOUNT Type: Character Len: 42 Index: [cisamdemo.idx key #3] Key: DEALER+BRANCH+AFSREP+SUBSTR(PROCDATE,5,2) +SUBSTR(CONTROL,2,4) Type: Character Len: 28
The Recital C-ISAM bridge makes full use of the C-ISAM indexes. SQL SELECT statements with WHERE clauses are optimized based on any of the existing indexes when possible. The following ODBC SELECT call makes use of key #3 rather than sequentially searching through the data file.
SQLExecDirect: In: hstmt = 0x00761BE8, szSqlStr = "select * from cisamdemo where dealer+branch+afsrep=' 00161 595-7912", cbSqlStr = -3 Return: SQL_SUCCESS=0 Get Data All: "DD", "CONFIRM", "PROCDATE", "CONTROL", "DOLLARS", "DEALER", "TERRITORY", "WOREP", "CURRTRAN", "TRADDATE", "CITY", "ACCOUNT", "PRETRAN", "AFSREP", "REPKEY", "BRANCH", "WODEALER", "BANKCODE", "COMMRATE", "NEWREP", "SETTLE", "POSTDATE" "0159", " 15522", "930312", "13356", 4992.60, "00161", "19", "", "210", "930305", "", "70000100009", "", "595-7912", "930315791", "", "", "59", 0.0000, "1", "", "930315" 1 row fetched from 22 columns.
Using the Recital/4GL, the primary index is set as the master index when the bridge is first opened. Any secondary indexes can be selected using the SET ORDER TO <expN> command. The Recital/4GL SEEK or FIND commands and SEEK() function can be used to search in the current master index.
> SET ORDER TO 3 Master index: [cisamdemo.idx key #3] > SEEK “00161 595-7912”
Appendix 1: Data Types
Informix |
Recital |
Byte |
Numeric |
Char |
Character |
Character |
Character |
Date |
Date |
Datetime |
Character |
Decimal |
Numeric |
Double Precision |
Float |
Float |
Real |
16 Bit Integer |
Short |
Integer |
Numeric |
Interval |
Character |
32 Bit Long |
Integer |
Money |
Numeric |
Numeric |
Numeric |
Real |
Numeric |
Smallfloat |
Numeric |
Smallint |
Numeric |
Text |
Unsupported |
Varchar |
Character |
Appendix 2: C-ISAM RDD Error Messages
The following errors relate to the use of the Recital CISAM Replaceable Database Driver (RDD). They can be received as an ‘errno <expN>’ on Recital error messages:
ERRNO() |
Error Description |
100 |
Duplicate record |
101 |
File not open |
102 |
Invalid argument |
103 |
Invalid key description |
104 |
Out of file descriptors |
105 |
Invalid ISAM file format |
106 |
Exclusive lock required |
107 |
Record claimed by another user |
108 |
Key already exists |
109 |
Primary key may not be used |
110 |
Beginning or end of file reached |
111 |
No match was found |
112 |
There is no “current” established |
113 |
Entire file locked by another user |
114 |
File name too long |
115 |
Cannot create lock file |
116 |
Memory allocation request failed |
117 |
Bad custom collating |
118 |
Duplicate primary key allowed |
119 |
Invalid transaction identifier |
120 |
Exclusively locked in a transaction |
121 |
Internal error in journaling |
122 |
Object not locked |
Usually, you do not need to setup an email server under Linux. Most GUI email clients support Gmail POP3 and IMAP configurations. But, how do you send mail via the standard /usr/bin/mail user agents in a shell script? Programs such as sendmail / postfix / exim can be configured as a gmail smarthost but they are largely overkill for this use. The ssmtp program is a neat utility that does just that for you via gmail.
- New MD5( expC ) function to calculate an MD5 crypto key from any character expression
- New MD5FILE( expC ) function calculates an MD5 crypto key for a given filename. If the filename is a pattern e.g *.* it will calculate the key across all files matching the pattern
- New mod_recital.so available for using Recital Web on linux x86_32
- New mod_recital64.so available for using Recital Web on linux x86_64
There is a good article on the gluster website here which gives some good information regarding file system optimization suitable for a HA Recital cluster solution.
try open database southwind catch die("Cannot open database, please try later.") endtry