Computer Awareness GK Questions with Answers – Page 6

Larry Page and Sergey Brin were research students at Stanford University when they built a search engine that ranked pages by the links pointing to them, and they registered Google as a company in 1998.

Microsoft was founded in 1975 by Bill Gates and Paul Allen at Albuquerque in New Mexico, moved to the Seattle area in 1979 and has had its main campus at Redmond in Washington state ever since.

Linux treats upper and lower case as different, so a file named Report is not the same as report, and it is built as a multi-user, multitasking system in which several accounts can work at once with separate permissions and a login.

Writing a command followed by two greater-than signs and a file name appends the output to the end of that file and keeps whatever was already in it, which is how log files are built up.

The command rmdir deletes a directory only if nothing is left inside it and prints an error such as directory not empty otherwise, which makes it a safe way to clear away empty folders.

The name is read as eight dot three: up to eight characters for the name, a dot, and up to three for the extension, as in LETTER.TXT or AUTOEXEC.BAT, with spaces and certain punctuation marks not allowed.

The command ps, short for process status, prints a list of processes with their process identification numbers, the terminal they belong to, the processor time used and the command that started each one.

A question mark in a file specification matches any single character in that position, so the command DIR FILE?.TXT lists FILE1.TXT and FILEA.TXT but not FILE12.TXT.

In the numeric form of chmod each of the three digits stands for one set of users, in the order owner, group and others, and each digit is the sum of read as 4, write as 2 and execute as 1.

Torvalds, then a student at the University of Helsinki in Finland, wrote a free kernel for personal computers and released it in 1991 under the GNU General Public Licence, which allowed anyone to study, change and redistribute it.

The cat command, short for concatenate, writes the contents of one or more files to the standard output, which is normally the screen, and so does the work of TYPE in MS-DOS.

The name stands for print working directory, and the command prints the complete path of the directory in which the shell is placed at that moment, counted from the root directory written as a single forward slash.

An internal command is written into the command interpreter COMMAND.COM and is loaded into memory along with the operating system, so it can be used even when no separate program file is present on the disk.

In black-box testing the tester treats the program as a sealed box, supplies inputs drawn from the specification and compares the outputs with what the specification promises; equivalence partitioning and boundary value analysis are its standard techniques, and no knowledge of the source code is needed.

A code walk-through is an informal review technique: a few team members read a module line by line, mentally execute it on sample data and note the defects they find, without the checklists, metrics and formal records of an inspection.

Boehm described the spiral model, in which the project moves outward through repeated loops and each loop performs four activities: determining objectives, risk analysis and resolution, development and testing, and planning the next loop.

If one module must know the internal data or logic of another to work, the two are tightly coupled, and a change in one forces a change in the other.

This is the first phase of the SDLC: the team meets the users, records what the system must do and what constraints apply, and sets it all down in the Software Requirements Specification, which then becomes the agreed basis for everything that follows and the yardstick for acceptance testing.

The Waterfall model is called the linear sequential model because the project flows in one direction through requirement analysis, design, coding, testing, deployment and maintenance, with each phase completed and signed off before the next begins and no overlap between them.

Binary search compares the key with the middle element and throws away half the array at every step, so the number of comparisons grows with the logarithm of the array size; an array of a million sorted items needs about twenty comparisons.