If you have 4 GB or more RAM use the Linux kernel compiled for PAE capable machines. Your machine may not show up total 4GB ram. All you have to do is install PAE kernel package.
This package includes a version of the Linux kernel with support for up to 64GB of high memory. It requires a CPU with Physical Address Extensions (PAE).
The non-PAE kernel can only address up to 4GB of memory. Install the kernel-PAE package if your machine has more than 4GB of memory (>=4GB).
# yum install kernel-PAE
If you want to know how much memory centos is using type this in a terminal:
# cat /proc/meminfo
http://kbala.com/ie-9-supports-corner-radius/
This guide will assist you in setting up an rsnapshot backup server on your network. rsnapshot uses rsync via ssh to perform unattended backups of multiple systems in your network. The guide can be found on the centos website here.
# recital < mrprog.prgIndividual commands can be executed in shell scripts.
# recital < myprog.prg > myoutput.txt
# recital > myoutput.txt <<END
use customers
list structure
END
# echo "select * from sales!customers where overdue" | recital | wc -l
# recital -c "create database sales"Expressions can be evaluated and used in shell scripts.
# recital -c "create table sales!invoices (id int, name char(25), due date)"
# VER=`recital -e "version(1)"`You can view what command line options are available by typing:
# recital --help
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.
In this article Barry Mavin, CEO and Chief Software Architect for Recital details how to Build C Extension Libraries to use with Recital.
Overview
It is possible to extend the functionaliy of Recital products using "Extension libraries" that can be written in C. These extension libraries, written using the Recital/SDK API, are dynamically loadable from all Recital 9 products. This includes:
- Recital
- Recital Server
- Recital Web
Building C Extension Libraries
You can create C wrappers for virtually any native operating system function and access these from the Recital 4GL. Unlike traditional APIs which only handle the development of C functions that are callable from the 4GL, the Recital/SDK allows you to build Classes that are accessible from all Recital products. e.g. You could create a GUI framework for Linux that handles VFP system classes!
To deploy your C Extension Libraries, copy them to the following location:
Windows:
\Program Files\Recital\extensions
Linux/Unix:
/opt/recital/extensions
Please see the Recital/SDK API Reference documentation for further details.
Sample code
Listed below is the complete example of a C Extension Library.:
////////////////////////////////////////////////////////////////////////////////
#include "mirage_demo.h"
////////////////////////////////////////////////////////////////////////////////
// Declare your functions and classes below as follows:
//
// Recital Function Name, C Function Name, Type (Function or Class)
//
#define MAX_ELEMENTS 7
static struct API_SHARED_FUNCTION_TABLE api_function_table[MAX_ELEMENTS] = {
{"schar", "fnSamplesCharacter", API_FUNCTION},
{"stype", "fnSamplesType", API_FUNCTION},
{"slog", "fnSamplesLogical", API_FUNCTION},
{"snum", "fnSamplesNumeric", API_FUNCTION},
{"sopen", "fnSamplesOpen", API_FUNCTION},
{"myclass", "clsMyClass", API_CLASS},
{NULL, NULL, -1}
};
////////////////////////////////////////////////////////////////////////////////
// Recital API initialization. This should be in only ONE of your C files
// **IT SHOULD NEVER BE EDITED OR REMOVED**
INIT_API;
///////////////////////////////////////////////////////////////////////
// This is an example of passing a character parameter and returning one.
RECITAL_FUNCTION fnSamplesCharacter(void)
{
char *arg1;
if (!_parse_parameters(PCOUNT, "C", &arg1)) {
ERROR(-1, "Incorrect parameters");
}
_retc(arg1);
}
///////////////////////////////////////////////////////////////////////
// This is an example of passing a numeric parameter and returning one.
RECITAL_FUNCTION fnSamplesNumeric(void)
{
int arg1;
if (!_parse_parameters(PCOUNT, "N", &arg1)) {
ERROR(-1, "Incorrect parameters");
}
_retni(arg1);
}
///////////////////////////////////////////////////////////////////////
// This is an example returns the data type of the parameter passed.
RECITAL_FUNCTION fnSamplesType(void)
{
char result[10];
if (PCOUNT != 1) {
ERROR(-1, "Incorrect parameters");
}
switch (_parinfo(1)) {
case API_CTYPE:
strcpy(result, "Character");
break;
case API_NTYPE:
strcpy(result, "Numeric");
break;
case API_LTYPE:
strcpy(result, "Logical");
break;
case API_DTYPE:
strcpy(result, "Date");
break;
case API_TTYPE:
strcpy(result, "DateTime");
break;
case API_YTYPE:
strcpy(result, "Currency");
break;
case API_ATYPE:
strcpy(result, "Array");
break;
default:
strcpy(result, "Unkown");
break;
}
_retc(result);
}
///////////////////////////////////////////////////////////////////////
// This is an example returns "True" or False.
RECITAL_FUNCTION fnSamplesLogical(void)
{
char result[10];
int arg1;
if (!_parse_parameters(PCOUNT, "L", &arg1)) {
ERROR(-1, "Incorrect parameters");
}
if (arg1) strcpy(result, "True");
else strcpy(result, "False");
_retc(result);
}
///////////////////////////////////////////////////////////////////////
// This example opens a table.
RECITAL_FUNCTION fnSamplesOpen(void)
{
char *arg1;
if (!_parse_parameters(PCOUNT, "C", &arg1)) {
ERROR(-1, "Incorrect parameters");
}
if (_parinfo(1) == API_CTYPE) {
_retni(COMMAND(arg1));
} else {
_retni(-1);
}
}
///////////////////////////////////////////////////////////////////////
// Define the MyClass CLASS using the API macros
///////////////////////////////////////////////////////////////////////
RECITAL_EXPORT int DEFINE_CLASS(clsMyClass)
{
/*-------------------------------------*/
/* Dispatch factory methods and return */
/*-------------------------------------*/
DISPATCH_FACTORY();
/*---------------------------------*/
/* Dispatch constructor and return */
/*---------------------------------*/
DISPATCH_METHOD(clsMyClass, Constructor);
/*--------------------------------*/
/* Dispatch destructor and return */
/*--------------------------------*/
DISPATCH_METHOD(clsMyClass, Destructor);
/*-----------------------------------*/
/* Dispatch DEFINE method and return */
/*-----------------------------------*/
DISPATCH_METHOD(clsMyClass, Define);
/*------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property NumValue */
/* then return. */
/*------------------------------*/
DISPATCH_PROPSET(clsMyClass, NumValue);
DISPATCH_PROPGET(clsMyClass, NumValue);
/*------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property LogValue */
/* then return. */
/*------------------------------*/
DISPATCH_PROPSET(clsMyClass, LogValue);
DISPATCH_PROPGET(clsMyClass, LogValue);
/*-------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property DateValue */
/* then return. */
/*-------------------------------*/
DISPATCH_PROPSET(clsMyClass, DateValue);
DISPATCH_PROPGET(clsMyClass, DateValue);
/*-------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property TimeValue */
/* then return. */
/*-------------------------------*/
DISPATCH_PROPSET(clsMyClass, TimeValue);
DISPATCH_PROPGET(clsMyClass, TimeValue);
/*-------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property CurrValue */
/* then return. */
/*-------------------------------*/
DISPATCH_PROPSET(clsMyClass, CurrValue);
DISPATCH_PROPGET(clsMyClass, CurrValue);
/*-------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property CharValue */
/* then return. */
/*-------------------------------*/
DISPATCH_PROPSET(clsMyClass, CharValue);
DISPATCH_PROPGET(clsMyClass, CharValue);
/*------------------------------*/
/* Dispatch SET or GET PROPERTY */
/* method for property ObjValue */
/* then return. */
/*------------------------------*/
DISPATCH_PROPSET(clsMyClass, ObjValue);
DISPATCH_PROPGET(clsMyClass, ObjValue);
/*-----------------------------------*/
/* If message not found return error */
/*-----------------------------------*/
OBJECT_RETERROR("Unknown message type");
}
////////////////////////////////////////////////////////////////////////////////
// Define METHOD handlers
////////////////////////////////////////////////////////////////////////////////
DEFINE_METHOD(clsMyClass, Constructor)
{
struct example_data *objectDataArea;
/* Allocate memory for objects objectData area */
objectDataArea = (struct example_data *)
malloc(sizeof(struct example_data));
if (objectDataArea == NULL) return(-1);
/* Assign the default property values */
strcpy(objectDataArea->prop_charvalue, "Test API object");
objectDataArea->prop_numvalue = 15.2827;
objectDataArea->prop_logvalue = 'F';
strcpy(objectDataArea->prop_datevalue, DATE_DATE());
strcpy(objectDataArea->prop_timevalue, DATE_DATETIME());
strcpy(objectDataArea->prop_currvalue, "15.2827");
strcpy(objectDataArea->object_name, "APIobject");
objectDataArea->prop_objvalue
= OBJECT_NEW(objectDataArea->object_name, "exception", NULL);
/* Set the object objectData area */
OBJECT_SETDATA((char *)objectDataArea);
return(0);
}
DEFINE_METHOD(clsMyClass, Destructor)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData != NULL) {
if (objectData->prop_objvalue != NULL)
OBJECT_DELETE(objectData->prop_objvalue);
free(objectData);
objectData = NULL;
}
return(0);
}
DEFINE_METHOD(clsMyClass, Define)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
char buffer[512];
int rc;
/* Check the object class */
OBJECT_GETPROPERTY(objectData->prop_objvalue, "class", buffer);
rc = OBJECT_GETARG(buffer, &result);
if (result.errno == 0 && result.type == 'C'
&& strcmp(result.character, "Exception") == 0) {
switch (OBJECT_GETARGC()) {
case 1:
rc = OBJECT_GETPARAMETER(1, &result);
if (result.errno == 0 && result.type == 'C') {
OBJECT_SETARG(buffer, &result);
rc = OBJECT_SETPROPERTY(objectData->prop_objvalue,
"message", buffer);
}
break;
case 2:
rc = OBJECT_GETPARAMETER(2, &result);
if (result.errno == 0 && result.type == 'N') {
OBJECT_SETARG(buffer, &result);
rc = OBJECT_SETPROPERTY(objectData->prop_objvalue,
"errorno", buffer);
}
}
}
result.type = 'L';
result.logical = (rc == 0 ? 'T' : 'F');
OBJECT_RETRESULT(&result);
}
////////////////////////////////////////////////////////////////////////////////
// Define GET property handlers
////////////////////////////////////////////////////////////////////////////////
DEFINE_PROPERTYGET(clsMyClass, NumValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('N', objectData->prop_numvalue);
}
DEFINE_PROPERTYGET(clsMyClass, LogValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('L', objectData->prop_logvalue);
}
DEFINE_PROPERTYGET(clsMyClass, DateValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('D', objectData->prop_datevalue);
}
DEFINE_PROPERTYGET(clsMyClass, TimeValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('T', objectData->prop_timevalue);
}
DEFINE_PROPERTYGET(clsMyClass, CurrValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('Y', objectData->prop_currvalue);
}
DEFINE_PROPERTYGET(clsMyClass, CharValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('C', objectData->prop_charvalue);
}
DEFINE_PROPERTYGET(clsMyClass, ObjValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
if (objectData == NULL) return(-1);
OBJECT_RETPROPERTY('O', objectData->prop_objvalue);
}
////////////////////////////////////////////////////////////////////////////////
// Define SET property handlers
////////////////////////////////////////////////////////////////////////////////
DEFINE_PROPERTYSET(clsMyClass, NumValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
int rc = OBJECT_ERROR;
OBJECT_GETVALUE(&result);
if (result.errno == 0 && result.type == 'N') {
objectData->prop_numvalue = result.number;
rc = OBJECT_SUCCESS;
}
return(rc);
}
DEFINE_PROPERTYSET(clsMyClass, LogValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
int rc = OBJECT_ERROR;
OBJECT_GETVALUE(&result);
if (result.errno == 0 && result.type == 'L') {
objectData->prop_logvalue = result.logical;
rc = OBJECT_SUCCESS;
}
return(rc);
}
DEFINE_PROPERTYSET(clsMyClass, DateValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
int rc = OBJECT_ERROR;
OBJECT_GETVALUE(&result);
if (result.errno == 0 && result.type == 'D') {
strcpy(objectData->prop_datevalue, DATE_DTOS(result.date));
rc = OBJECT_SUCCESS;
}
return(rc);
}
DEFINE_PROPERTYSET(clsMyClass, TimeValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
int rc = OBJECT_ERROR;
OBJECT_GETVALUE(&result);
if (result.errno == 0 && result.type == 'T') {
strcpy(objectData->prop_timevalue, DATE_TTOS(result.datetime));
rc = OBJECT_SUCCESS;
}
return(rc);
}
DEFINE_PROPERTYSET(clsMyClass, CurrValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
int rc = OBJECT_ERROR;
OBJECT_GETVALUE(&result);
if (result.errno == 0 && result.type == 'Y') {
strcpy(objectData->prop_currvalue, CURR_YTOS(result.currency));
rc = OBJECT_SUCCESS;
}
return(rc);
}
DEFINE_PROPERTYSET(clsMyClass, CharValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
struct API_EXPRESSION result;
int rc = OBJECT_ERROR;
OBJECT_GETVALUE(&result);
if (result.errno == 0 && result.type == 'C') {
strcpy(objectData->prop_currvalue, result.character);
rc = OBJECT_SUCCESS;
}
return(rc);
}
DEFINE_PROPERTYSET(clsMyClass, ObjValue)
{
struct example_data *objectData = (struct example_data *)OBJECT_GETDATA();
OBJECT objvalue;
int rc = OBJECT_ERROR;
if (OBJECT_GETTYPE() == 'O') {
objvalue = OBJECT_GETOBJECT();
objectData->prop_objvalue = OBJECT_ASSIGN(objvalue, objectData->object_name);
rc = OBJECT_SUCCESS;
}
return(rc);
} Here is a simple shell script to copy your ssh authorization key to a remote machine so that you can run ssh and scp without having to repeatedly login.
#!/bin/sh
# save in file ssh_copykeyto.sh then chmod +x ssh_copykeyto.sh
KEY="$HOME/.ssh/id_rsa.pub"
if [ ! -f ~/.ssh/id_rsa.pub ];then
echo "private key not found at $KEY"
echo "create it with "ssh-keygen -t rsa" before running this script
exit
fi
if [ -z $1 ];then
echo "Bad args: specify user@host as the first argument to this script"
exit
fi
echo "Copying ssh authorization key to $1... "
KEYCODE=`cat $KEY`
ssh -q $1 "mkdir ~/.ssh 2>/dev/null; chmod 700 ~/.ssh; echo "$KEYCODE" >> ~/.ssh/authorized_keys; \ chmod 644 ~/.ssh/authorized_keys"
echo "done!"
In this article Barry Mavin, CEO and Chief Software Architect for Recital, details Working with Stored Procedures in the Recital Database Server.
Overview
Stored procedures and user-defined functions are collections of SQL statements and optional control-of-flow statements written in the Recital 4GL (compatible with VFP) stored under a name and saved in a Database. Both stored procedures and user-defined functions are just-in-time compiled by the Recital database engine. Using the Database Administrator in Recital Enterprise Studio, you can easily create, view, modify, and test Stored Procedures, Triggers, and user-defined functions
Creating and Editing Stored Procedures
To create a new Stored Procedure, right-click the Procedures node in the Databases tree of the Project Explorer and choose Create. To modify an existing stored procedure select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it or selecting Modify from the context menu . By convertion we recommend that you name your Stored Procedures beginning with "sp_xxx_", user-defined functions with "f_xxx_", and Triggers with "dt_xxx_", where xxx is the name of the table that they are associated with.
Testing the Procedure
To test run the Stored Procedure, select the Stored Procedure in the Databases Tree in the Project Explorer by double-clicking on it. Once the Database Administrator is displayed, click the Run button to run the procedure.
Getting return values
Example Stored Procedure called "sp_myproc":
parameter arg1, arg2 return arg1 + arg2
Example calling the Stored Procedure from C# .NET:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;
////////////////////////////////////////////////////////////////////////
// sample code to call a Stored Procedure that adds to numeric values together
public int CallStoredProcedure()
{
RecitalConnection conn = new
RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
RecitalCommand cmd = new RecitalCommand();
cmd.Connection = conn;
cmd.CommandText = "sp_myproc(@arg1, @arg2)";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters["@arg1"].Value = 10;
cmd.Parameters["@arg2"].Value = 20;
conn.Open();
cmd.ExecuteNonQuery();
int result = (int)(cmd.Parameters["retvalue"].Value); // get the return value from the sp
conn.Close();
return result;
}
Writing Stored Procedures that return a Resultset
If you want to write a Stored Procedure that returns a ResultSet, you use the SETRESULTSET() function of the 4GL. Using the Universal .NET Data Provider, you can then execute the 4GL Stored Procedure and return the ResultSet to the client application for processing. ResultSets that are returned from Stored Procedures are read-only.
Example Stored Procedure called "sp_myproc":
parameter query
select * from customers &query into cursor "mydata"
return setresultset("mydata")
Example calling the Stored Procedure from C# .NET:
////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;
////////////////////////////////////////////////////////////////////////
// sample code to call a stored procedure that returns a ResultSet
public void CallStoredProcedure()
{
RecitalConnection conn = new
RecitalConnection("Data Source=localhost;Database=southwind;uid=?;pwd=?");
RecitalCommand cmd = new RecitalCommand();
cmd.Connection = conn;
cmd.CommandText = "sp_myproc(@query)";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters["@query"].Value = "where not deleted()";
conn.Open();
RecitalDataReader dreader = cmd.ExecuteReader();
int sqlcnt = (int)(cmd.Parameters["sqlcnt"].Value); // returns number of affected rows
while (dreader.Read())
{
// read and process the data
}
dreader.Close();
conn.Close();
} Here's how to set up field validation for a field with a small static number of acceptable values.
Using the example.dbf table from the southwind sample database, validation can be added to the title field to ensure it matches one of a list values.
open database southwindThe inlist() function checks whether the specified expression exists in the comma-separated list which follows. An attempt to update title with a value not in the list will give an error: Validation on field 'TITLE' failed.
alter table example add constraint;
(title set check inlist(alltrim(title),"Miss","Mr","Mrs","Ms"))
If you have access to the Recital Workbench, you can use the modify structure worksurface to add and alter your dictionary entries, including a customized error message if required.
