System Programming

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Kernel and system programming is the process of creating the software necessary for a computer or device to function and operate other programs. Some operating systems (such as Microsoft Windows) are proprietary, but others, such as the various Linux distributions, are open source.

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visio 2013 standard does not show the "UML Sequence" template as shown below
https://www.youtube.com/watch?v=_xtZIDI8Ajg
only professional viso 2013 shows it?
are there existing sample diagrams which i can use as sample and modify on top of them easily?
any alternate tool to draw these type of diagrams easily apart from visio like free open source tools?
Please advise
0
Microsoft Azure 2017
LVL 12
Microsoft Azure 2017

Azure has a changed a lot since it was originally introduce by adding new services and features. Do you know everything you need to about Azure? This course will teach you about the Azure App Service, monitoring and application insights, DevOps, and Team Services.

how to understand big new project code quickly and effectively to write new enhancement to existing code or to fix some defects or to debug to improve some areas of poor performance.

what are the tips and recommendations , best practices around this
Please advise
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In Enterprise Architect, how do you turn functional requirements into use cases?

I have tried to open the Relationship Matrix and then added use cases through it. But it seems like that is not the intended process.

The process I am looking for will be smooth.

I have requirements that I need to put into requirement groups. Then use cases I need to put into use case groups. The system is rather big.
Can you guide me to any example where EA is used and has the full tracebility of requirements to use cases, domain model, interfaces, and components?

I want to understand how to get from requirements to components, interfaces, and operations in EA
0
hello
I have a file name info.txt under /etc/
this file contain four lines the fourth line have expiration:data
I want to check this data if it's today+10Days then create a new file name:done.txt and contain done.
else do noting.
thanks.
0
Hi Experts,
we have a site created in Caspio that has some required fields.
We realized that some of the required fields are coming thru w/o containing data.
So were told by Caspio that is probably due to those users using an old browser.
They created a field named user_agent that will capture which browser were used for each record data entry.
Now I created a list of all records with missing data in required field along with the data captured in this field named user_agent (browser).
See attached.
Wondering what are those values are and how can we sent a message informing this and this browser is not supported...
Thanks
Untitled.png
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Hello,
I have a FreeBSD and ubuntu server.
I crate a cronjob to execute in specific time. but the command that I do required a full privilege on system... so how I can make the cronjob work with root for example ?
thanks.
0
Hi

We need to regularly create system restore points on our user computers via command line.

The idea is to automate this process without deploying any 3rd party tools.

Step 1. Check if system restore is enabled on the computer. If it is not, enable it.
Step 2. Check the storage size allocated for system restore. If it is less than 6 GB, configure to to be 6 GB.
Step 3. Create a system restore point with a generic label e.g. "maintenance".
Step 4. Check if the system restore point got created or not by listing existing system restore points and comparing the labels with the generic label used in step3.


So this is the general idea of the script we want to create and I think I can do the other bits myself except for creating system restore point via command line.

I have tried the WMIC method, powershell method and everything else I can find on blogs and google search.

Most commands I run return the "execution successful" message.

But when I check manually if the system restore point got created or not by opening system restore GUI, I don't see the restore point created.

For the life of me I can't figure out what's going on.

So pls help !
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Hi,
What can be reason to the below error, while it only happens when I deployed the same project to https (everything is fine if I deploy it to http)?

Server Error in '/RegRec2' Application.
The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.InvalidOperationException: The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[InvalidOperationException: The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine.]
   System.Data.OleDb.OleDbServicesWrapper.GetDataSource(OleDbConnectionString constr, DataSourceWrapper& datasrcWrapper) +258
   System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) +497
   System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) +100
   System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection 

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In short, I would say:

A flag is a predefined bit or bit sequence that holds a binary value.

A mode is a distinct setting.

So it's not always possible to replace the term "mode" by "flag". This is only possible if it's about a binary value. I got confused by these terms when reading:

http://man7.org/linux/man-pages/man2/open.2.html

The argument flags must include one of the following access modes:
O_RDONLY, O_WRONLY, or O_RDWR.

The file creation flags are O_CLOEXEC,
O_CREAT, O_DIRECTORY, O_EXCL, O_NOCTTY, O_NOFOLLOW, O_TMPFILE, and
O_TRUNC.

The file status flags are all of the remaining flags listed
below.

Why they just don't say:

The file access flags are O_RDONLY, O_WRONLY, and O_RDWR.

Why they suddenly use a different term when it's about "access"? Probably behind the scenes it's also just about a binary value, right? Probably all O_VARIABLE's above are 0 or 1.

And see: https://en.wikipedia.org/wiki/File_descriptor

This table records the mode with which the file (or other resource) has been opened: for reading, writing, appending, and possibly other modes.

So Wikipedia uses the term "mode" only (and not flag). At least they are consistent, because they call them all "modes".

Is there a specific reason why sometimes mode is used and something flag (while it's about the same thing)? I would stay, be at least consistent to avoid confusion.
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By default, the first three rows of a "file descriptor table" consists of:

FD 0 (standard input,  associated with keyboard)
FD 1 (standard output, associated with screen)
FD 2 (standard error,  associated with screen)

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These file descriptors point to one or more rows in the "open file table". Imagine we only have these three file descriptors. Then how does the "open file table" look like?

Usually all three file descriptors point to the same file, but that doesn't mean they point to the same entry in the "open file table". So how the open file table looks like?

_ | offset | reference count | permissions | flags | pointers
_ |    ?   |        ?        |      ?      |   ?
possible more rows

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The lsof command shows for example:

lsof        721    root    0u      CHR              136,1       0t0          4 /dev/pts/1
lsof        721    root    1u      CHR              136,1       0t0          4 /dev/pts/1
lsof        721    root    2u      CHR              136,1       0t0          4 /dev/pts/1

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The file "/dev/pts/1" is CHR (character special file). They all point to the same file.
I'm also wondering why it's for example "0u" and not "0r"? The file descriptor 0 stands for input, so it only has to read something.

r for read access;
w for write access;
u for read and write access;

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I would expect something like: 0r, 1w, 2w instead of 0u, 1u, 2u? And what are the offsets et cetera?
0
HTML5 and CSS3 Fundamentals
LVL 12
HTML5 and CSS3 Fundamentals

Build a website from the ground up by first learning the fundamentals of HTML5 and CSS3, the two popular programming languages used to present content online. HTML deals with fonts, colors, graphics, and hyperlinks, while CSS describes how HTML elements are to be displayed.

hi,

i have script working.
When it runs it check for files and send email alert if not files and also if has files.
Currently it sending the email alerts text format.
Request experts help, want to send email with htm format.
and for errors it should bold the text and color RED.
can help...


#Requires -version 3.0
$WarningPreference="Continue"
function Send-Mail
{
  param (
    [string] $Email_Subject,
    [string] $Email_Body,
    [string] $Email_Attachment
  )
  Send-MailMessage -SmtpServer 'mailserver.com' `
  -Body $Email_Body `
  -From 'donotreply@mail.com' `
  -To 'admin@mail.com' `
  -Subject $Email_Subject `
  -Attachments $Email_Attachment
}
function Send-Error
{
  Write-Host "Sending Error Alert @ $emaildate"
  $subject = "ACTION REQUIRED : Error Alert @ $emaildate"
  $logcontents = get-content $Logfile | Out-String
  $Body = "Dear All,`n`nThis email sent by system for errors highlighted below."  + $logcontents + "`n Regards,`n Job Process"
  Send-Mail -Email_Subject $subject -Email_Body $Body -Email_Attachment $Logfile }
function send-status
{
  Write-Host "Sending Success Alert @ $emaildate"
  $subject = "INFO : Success Alert @ $emaildate"
  $logcontents = get-content $Logfile | Out-String
  $Body = "Dear All,`n`nThis email sent by system for your information"  + $logcontents + "`n Regards,`n Job Process"
  Send-Mail -Email_Subject $subject -Email_Body $Body -Email_Attachment $Logfile }

  #check if source files exists
0
I am trying ssh into a remote server, capturing the process ID, and stopping the app using the process ID.

For some reason I am loosing the value of the variable PROCESS in the SSH session,  all the logic works fine if i run it locally. Below is the code and the execution part where i am loosing the variable (PROCESS) Value. Can someone tell me why i am not able to capture the echo "$PROCESS" and $PROCESS below.

Stoptomcat()
{
. /apps/web/properties/tomcat.props
for server in "${dev_host_Array[@]}"
 do
        echo "connecting to the server $server" | tee -a /tmp/tomcat-App-operation.${now}.txt
        ssh -q "$server" bash -c "'
         PROCESS=`ps -ef | grep $app_name | grep -v "grep" | grep -v "Tom.sh" | awk '{print $2}'`
         echo "$PROCESS"
      if [ ! -x $PROCESS ]; then
         /apps/tomcat/$app_name/bin/catalina.sh stop | tee -a /tmp/tomcat-App-operation.${now}.txt &
         pid=$!
         declare -i elapsed=0
           while ps -p ${pid} >/dev/null; do
            sleep 1
             if ((++elapsed % 60 == 0)); then
               kill -9 $process
                exit
             fi
           done
  else
   echo " TOMCAT $app_name is already in stopped state"
fi
'"
done
}

Execution:

+ for server in '"${dev_host_Array[@]}"'
+ tee -a /tmp/tomcat-App-operation.1536692015.txt
+ echo 'connecting to the server testserver1'
connecting to the server testserver1
++ ps -ef
++ grep -v Tom.sh
++ awk '{print $2}'
++ grep …
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I have to migrate the FS GPFS (3.4) on AIX server on new NSD disks, under the current configuration.
Which replication procedure is best to use?

[root@crmcas01]/tmp# mmlsconfig
Configuration data for cluster TEST:
---------------------------------------------
myNodeConfigNumber 1
clusterName TEST
clusterId 13882357993337224079
autoload yes
minReleaseLevel 3.4.0.7
dmapiFileHandleSize 32
tiebreakerDisks tiebreaker01
worker1Threads 500
traceRecycle global
tracedevBufferSize 1048576
traceFileSize 300000000
trace all 4 tm 2 thread 1 mutex 1 vnode 5 ksvfs 2 klockl 2 io 3 pgalloc 1 mb 1 lock 2 fsck 3
pagepool 8G
nfsPrefetchStrategy 1
maxMBpS 2048
maxStatCache 256000
maxFilesToCache 64000
adminMode allToAll

File systems in cluster TEST:
--------------------------------------
/dev/SwReport
/dev/fsWBCp
/dev/fsCRMp
/dev/sbsiebCRMp
/dev/sbsiebgCRMp
0
Hi,
I have a requirement for an excel sheet to be formatted from a flat structure to a stacked structure. I'll try to explain:
In the flat structure has a number of basic columns, some of these columns repeat multiple times ('Transaction1', 'Transaction2', 'Transaction3'). some of the items will not have all transaction data, therefore some of those columns may be blank for a given item.

Example - https://imgur.com/B3h4Iir

I need to take this data structure and transform it in another sheet/workbook so it goes like this. The transaction is a single column with the transaction1,2,3 data repeating as row beneath the item, all other columns will remain blank. The next item will begin on the next available blank row.

Example - https://imgur.com/x8f2c4T

Thanks,
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Hi Experts,
I got an invitation from someone to upload something to their google drive, however when I click on new button, the upload options are disabled and a message appears stating "you are working offline, and some functions are not avail.."
What is the cause and how can I change it?
Thanks in advance
0
How to use c4.5 classifier in android studio to process the  accelerometer and and gyroscope  sensor data from phone.
0
Dual pipe producer/consumer blocked by read.

The issue is in the producer:
        read(consumer_to_producer[0], &cnt, sizeof(cnt));
        read(consumer_to_producer[0], shared_arr, sizeof(shared_arr));

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prevents the producer from working because the consumer has yet to write anything, how can I avoid this?


#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#define SIZE 10

int shared_arr[SIZE];
int cnt = 0, in = 0, out = 0;
int consumer_to_producer[2], producer_to_consumer[2];

void consumer();
void producer();

int main() {
    pipe(consumer_to_producer); // consumer to producer
    pipe(producer_to_consumer); // producer to consumer

    if (fork() == 0) {
        /* child process */
        consumer();
    } else {
        /* parent process */
        producer();
        sleep(3);
    }

    exit(0);
}

void consumer() {
    /* consumer process */
    close(producer_to_consumer[1]); // Close write end, we don't need it
    close(consumer_to_producer[0]); // This fcn doesn't need read end
    while (1) { 
        /* if buffer is full, consume it */
        // read in cnt from producer so we can check if it's full
        read(producer_to_consumer[0], &cnt, sizeof(cnt));

        if (cnt == SIZE) { /* If full, consume */
            read(producer_to_consumer[0], shared_arr, sizeof(shared_arr));
            printf("I am consuming\t%d\t%d\n", shared_arr[in], out);
            out = (out + 1) % SIZE;
            cnt--;
        } 

        

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In VBA while accessing Reference, error comes 'Error accessing the system Registry'

Your solution at the following webpage not found.
http://support.microsoft.com/default.aspx?scid=kb;en-us;269383

Please helo
0
I am writing a software removal program, and want to uninstall a context menu driver. Just unregistering the driver while Windows File Explorer is open causes a Windows error "Program has stopped working" when trying to unregister the dll. Closing file explorer first and then running the program works fine.

Here is the unregister code I am using now:

HINSTANCE hLib = LoadLibraryW(szDllPath);

    if (hLib == NULL)
    {
		DWORD dwErrorCode = GetLastError();
		szError.Format(_T("\nWindows could not load library %s due to %s"),szDllName,getLastWinError(dwErrorCode));
		return false;            
    }

    typedef HRESULT (CALLBACK *HCRET)(void);
    HCRET lpfnDllRegisterServer;

    // Find the entry point
    lpfnDllRegisterServer = (HCRET)GetProcAddress(hLib, "DllUnregisterServer");



    if (lpfnDllRegisterServer == NULL)
    {
		szError = NEWLINE;
		szError = ERR_PROCEDURE_ADDRESS;
		return false;            
    }

    // Call the function by function pointer..
    if (FAILED((*lpfnDllRegisterServer)()))            
    {   
		szError.Format(_T("\nWindows could not unregister context menu driver %s!"),szDllName);
		return false;            
    }

    FreeLibrary(hLib);

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What is the best way to go about this to avoid this Windows error?
0
Bootstrap 4: Exploring New Features
LVL 12
Bootstrap 4: Exploring New Features

Learn how to use and navigate the new features included in Bootstrap 4, the most popular HTML, CSS, and JavaScript framework for developing responsive, mobile-first websites.

What are the advantages and disadvantages of pipes ,fifo's,threads,sockets,shared memory,message queue's.And which of them i s faster?
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Can I assign co line 6 to a phone number as  part of system programming I want this a a 'panic' button to call a specific outside number
0
$check_email="select * form users where user email='$email'";
            $run_email = mysqli_query($con,$check_email);
      
            $check = mysqli_num_rows($run_email);
             
               if($check==1){
      
             echo "<script>alert('Email phone already exit,please try another!')</script>";
             exit();
0
I have recently learned C++ and C#. That is, I have taken courses to understand the basics of them and now want to start using them for professional work. I have said I want to take on projects that push me to learn a lot more about these vast programming languages. I have a hardware device name Griffin PowerMate. It is a USB knob/wheel that can be helpful controlling a computer. For some reason, it does not have great support on Window 7, 10. It does have a driver for Window XP and Vista. I cannot get this device to do what I want in Windows 10. However, on a Mac computer, the driver is up to date and does everything I want. So, to me this proves what I want on the Windows side is possible. Is it likely to think that without an SDK from the company I could use C++ or even C# to create a driver for this device?
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Hello I found this code here
<html>
<head>

<script>
      var updateRate = 50;    // Lower number gives higher update rate
      var sizeChange = 0.25;  // Lower number gives smaller difference in fontsize per update
                var numberOfLines = 24; // Set this to the number of lines
</script>
<style>



.vline {font-size: 0; margin: 0}
.line {font-size: 0; margin: 0; display: none}
</style>

</head>
<body bgcolor="black" text="white" topmargin="0" leftmargin="0" rightmargin="0" bottommargin="0" scroll="no">

<div style="position: absolute; left: -100%; top: 20%; width: 300%; height: 80%; overflow: hidden; text-align: center">
<p id="p0" class="line"> </p>
<p id="p1" class="line"> </p>
<p id="p2" class="line"> </p>
<p id="p3" class="line"> </p>
<p id="p4" class="line"> </p>
<p id="p5" class="line"> </p>
<p id="p6" class="line"> </p>
<p id="p7" class="line">All lines about the same length</p>
<p id="p8" class="line">Gives the best result I believe</p>
<p id="p9" class="line">All lines about the same length</p>
<p id="p10" class="line">Gives the best result I believe</p>
<p id="p11" class="line">All lines about the same length</p>
<p id="p12" class="line">Gives the best result I believe</p>
<p id="p13" class="line">All lines about the same length</p>
<p id="p14" class="line">Gives the best result I believe</p>
<p id="p15" class="line">All lines about the same length</p>
<p id="p16" class="line">Gives the best result I believe</p>
<p id="p17" class="line">All 

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0
I found this code very helpfull for my church site, but i would like to know if can add a loop so it repeat itself. Thank you
<html>
<head>

<script>
      var updateRate = 50;    // Lower number gives higher update rate
      var sizeChange = 0.25;  // Lower number gives smaller difference in fontsize per update
                var numberOfLines = 24; // Set this to the number of lines
</script>
<style>



.vline {font-size: 0; margin: 0}
.line {font-size: 0; margin: 0; display: none}
</style>

</head>
<body bgcolor="black" text="white" topmargin="0" leftmargin="0" rightmargin="0" bottommargin="0" scroll="no">

<div style="position: absolute; left: -100%; top: 20%; width: 300%; height: 80%; overflow: hidden; text-align: center">
<p id="p0" class="line"> </p>
<p id="p1" class="line"> </p>
<p id="p2" class="line"> </p>
<p id="p3" class="line"> </p>
<p id="p4" class="line"> </p>
<p id="p5" class="line"> </p>
<p id="p6" class="line"> </p>
<p id="p7" class="line">All lines about the same length</p>
<p id="p8" class="line">Gives the best result I believe</p>
<p id="p9" class="line">All lines about the same length</p>
<p id="p10" class="line">Gives the best result I believe</p>
<p id="p11" class="line">All lines about the same length</p>
<p id="p12" class="line">Gives the best result I believe</p>
<p id="p13" class="line">All lines about the same length</p>
<p id="p14" class="line">Gives the best result I believe</p>
<p id="p15" class="line">All …
0

System Programming

40K

Solutions

19K

Contributors

Kernel and system programming is the process of creating the software necessary for a computer or device to function and operate other programs. Some operating systems (such as Microsoft Windows) are proprietary, but others, such as the various Linux distributions, are open source.