Interview Questions

A system call is a function.subroutine which interrupts the currently executing program and transfers control to the interrupt routine.The contents of the executing program are saved and after the interrupt routine finishes its function,control is transferred back to the executing program. If we talk in the context of Linux then System calls are called kernel mode.

Whereas API (Application Programming Interface) is a function or a set of functions, objects, protocols or data-structures for the support of application development for developers/programmers. It is actually a kind of function definition which specifies how to make available of a specific service of the system/OS to the other program/process or system. Read more at: https://www.queryhome.com/48442/os-what-is-difference-between-system-call-and-api

Social engineering is the art of tricking users into performing certain harmful activities or attacks, users must be trained to identify social engineering. Social engineering attacks typically involve some form of psychological manipulation, fooling otherwise unsuspecting users or employees into handing over confidential or sensitive data. Commonly, social engineering involves email or other communication that invokes urgency, fear, or similar emotions in the victim, leading the victim to promptly reveal sensitive information, click a malicious link, or open a malicious file. Because social engineering involves a human element, preventing these attacks can be tricky for enterprises.

Cloud architecture provide large pool of dynamic resources that can be accessed any time whenever there is a requirement, which is not being given by the traditional architecture. In traditional architecture it is not possible to dynamically associate a machine with the rising demand of infrastructure and the services. Cloud architecture provides scalable properties to meet the high demand of infrastructure and provide on-demand access to the user.

The open items of an account can only be cleared once you post an identical offsetting amount to the account. In other words, the balance of the items assigned to each other must equal zero.During clearing, the system enters a clearing document number and the clearing date in these items. In this way, invoices in a vendor account are indicated as paid, and items in a bank clearing account are indicated as cleared.

You generally use the payment program to clear invoices. Manual clearing of open items is therefore not usually necessary. However, you will sometimes have to clear items manually if, for example, you receive a refund from your vendor or you have set up a direct debit procedure.

Files can be read and written by using java script functions – fopen(),fread() and fwrite().

The function fopen() takes two parameters – 1. Path and 2. Mode (0 for reading and 3 for writing). The fopen() function returns -1, if the file is successfully opened.

Ex: file=fopen(getScriptPath(),0);

The function fread() is used for reading the file content.

Ex: str = fread(file,flength(file));

The function fwrite() is used to write the contents to the file.

Ex(): file = fopen("c:\MyFile.txt", 3);// opens the file for writing

fwrite(file, str);// str is the content that is to be written into the file.

The PHP default variable $_PHP_SELF is utilized for the PHP script name and when you click "submit" catch then same PHP script will be called.