Linux Updates

What is a Process

An instance of a program is called a Process.

Any command that you give to your  Linux machine starts a new process.

It is possible that for the same program we have multiple processes.

Types of Processes

• Foreground Processes

• Background Processes

Processes in action

Process  running on system are actions running on system.

Jobs are specific to a user for that given shell where it is been run.

You can check the number of processes running by using command,

 ps aux

And also get the count of total processes by using command,

 ps aux | wc

A job run by user or root is specific to his profile and for that given shell.

It has nothing to do with system processes running.

Example,

You can write a job specific to shell, like,

 dd if=/dev/zero of=/dev/null

This job does nothing and shows nothing.

Input file - /dev/zero

Output file - /dev/null

Every command that we start from a shell is considered a shell job.

If we type command ls

So, this is shell job.

 They start and stop immediately since they have done their work.

 Hence it is important to know the difference between a job and process.

The best Linux distros for new Linux user:

 •Ubuntu for inThe very best Linux distros are tailored to specific types of users.

• Linux Mint A strong option for those new to Linux.

• Arch Linux is one of the most popular choices around.

 •Tails is a privacy-oriented Linux distro which has the aim of concealing your location and identity as   much as possible.

 •CentOS is designed to be super-reliable, which is why it’s a great choice for a server.

 Here are the few tips for you to fix your low graphic system!

Step 1 : press “ Ctrl- Alt- F1” then the terminal will be opened to do re-installation part.

Step 2 : Run this command “ sudo apt-get update” which means you are updating the settings.

Step 3 : After running it execute the below command 

             sudo apt-get -d install --reinstall gdm

Step 4 : Run this command in the termal following the above step

             sudo apt-get remove --purge gdm

             sudo apt-get install gdm

(Here gdm means graphic manager. it removes the old gdm and re-install the gdm again )

Step 5 : Before restarting the sytem execute this command.

             sudo reboot

Then you can use your pc without any problem.

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
int main()
{
int pid;            //process id
pid = fork();     //create another process
if ( pid < 0 )
{                                 //fail
printf(“
Fork failed
”);
exit (-1);
}
else if ( pid == 0 )
{                     //child
execlp ( “/bin/ls”, “ls”, “-l”, NULL );  //execute ls
}
else
{                             //parent
wait (NULL);              //wait for child
printf(“
child complete
”);
exit (0);
}
}