Which IRQ does COM1 commonly use?

Which IRQ does COM1 commonly use?

• 8
• 4
• 6
• 3 

EXPLANATION

Interrupt request (IRQ) 4 is normally used for the first serial port, COM1. This is also the default interrupt for the third serial port.
In a computer, an interrupt request is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Hardware interrupts are used to handle events such as receiving data from a modem or network card, key presses, or mouse movements.

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Which of these is NOT an alternative to Microsoft Excel?

Which of these is NOT an alternative to Microsoft Excel?

• LibreOffice Calc
• GIMP
• Gnumeric
• Google Drive - Sheets

EXPLANATION

GIMP is an image manipulation software for multiple platforms. WIkipedia describes it as a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, resizing, cropping, photo-montages, converting between different image formats, and more specialized tasks. https://en.wikipedia.org/wiki/GIMP
It is more like an alternative to Adobe PhotoShop.
The other applications are actually alternatives to Microsoft Excel.
https://alternativeto.net/software/microsoft-excel/

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In relation to Network Switches, what is the purpose of the spanning tree algorithm?

In relation to Network Switches, what is the purpose of the spanning tree algorithm?

• To help ensure that messages will arrive over all possible paths.
• To provide a path between every LAN segment.
• To discover a "loop free" topology and provide, as possible, a path between every pair of LAN's
• To keep routing updates from being transmitted onto the same port on which they were received. 

 

EXPLANATION

The spanning tree algorithm is a requirement in meshed transparent bridging. As a transparently bridged frame contains no record of the path it has taken, and contains no mechanism for aging, any bridge loop will result in storms of packets continually circulating around the loop. By providing a loop-free path between any two points in the network, the spanning tree algorithm prevents these storms. A form of this algorithm is also used for Explorer control in source-route bridges.

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In which of the following scenarios would you use a WORM backup tape?

In which of the following scenarios would you use a WORM backup tape?

• When the tape data is overwritten at random.
• When the tape data is written only once.
• When the tape data is overwritten monthly.
• When the tape or tapes are stored somewhere moist or dirty. 

EXPLANATION

WORM is an acronym for Write Once Read Many. WORM devices are physically designed to only ever be written to once but can be read from many times.

SOURCE

https://en.wikipedia.org/wiki/Linear_Tape-Open#WORM

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Which of the following wildcard characters can be used in the Windows command line as a substitute for a single character in a file or directory name?

Which of the following wildcard characters can be used in the Windows command line as a substitute for a single character in a file or directory name?

• *
• ?
• @
• $ 

EXPLANATION

The question mark (?) character can be used as a substitute for a single character in a file or directory name. The asterisk (*) character can be used as a wildcard character to replace zero or more characters.

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In Windows, If you close a tab in Firefox/Chrome/IE, what key command will re-open it for you?

In Windows, If you close a tab in Firefox/Chrome/IE, what key command will re-open it for you?

• Ctrl-Shift-T
• Ctrl-T-O
• Ctrl-Alt-T
• Ctrl-Alt-O-T      

EXPLANATION

When you realize you just closed that browser tab that you have kept open for the last 4 days... just in case. You can easily now just  type "Ctl - Shift - T" to get it back.

SOURCE

http://www.slate.com/blogs/future_tense/2013/08/22/keyboard_shortcut_helps_recover_lost_browser_tabs.html

       

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drw-r-x-wx 2 terry staff 4096 Mar 10 14:29 Secret <== Based on permissions assigned to user (terry), group (staff), and other, which non-root users have permission to remove files in directory "Secret?"

drw-r-x-wx 2 terry staff 4096 Mar 10 14:29 Secret <== Based on permissions assigned to user (terry), group (staff), and other, which non-root users have permission to remove files in directory "Secret?"

• Both owner "terry" and group "staff" members
• Any user in "other"
• The owner, user "terry"
• Any member of group "staff" 

EXPLANATION

To remove a file, a user needs write and access (execute) permission on the directory. That is, -wx at minimum.
The user does not need read permission on the directory to remove a file if the name is known, but read permission on the directory would be required to discover the filename, for example, with "ls".
User "terry", the owner, does not have access to the directory (x is absent for user).

SOURCE

https://www.hackinglinuxexposed.com/articles/20030424.html

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