Very Simple Question 1

[jbaker76786]

I had to install a new patch to an old Sun Microsystems computer yesterday.

It was fairly straightforward, I just had to type out exactly what was written in the set of instructions I was given by the company issuing out the upgrade.

My question is, what function do the arrow keys have when typing in code in CMS, running off Sun. The screen was all white and the screen appeared to flash black and white several times, towards the top of the screen every time I pressed the arrow keys (I was trying to bring the last line of code back up because I had made a mistake and didn't want to have to re-write the whole thing again but I guess that's only in MS-DOS which I'm more familiar with)?

So anybody know what the flashing black and white screen signifies and also what purpose (if any), the curser keys have when typing in code in that "MS-DOS looky-like" screen?

 

[Annihilannic]

The flashing was probably what is known as 'visual beep', i.e. the screen is flashed instead of emitting a beep sound, possibly because the terminal you were using is not capable of making sounds.

I presume you were logged in as root, and you were probably using the default Bourne shell, i.e. 'sh'. 'sh' is not capable of command history editing, and it wouldn't know how to handle arrow keys, so that could explain the beeps you were seeing.

The more popular shells such as ksh, csh, bash, etc. all have more features such as command histories and command-line editing, but 'sh' is the default for the root account for historical/compatibility reasons.

Annihilannic.

 

[jbaker76786]

Thanks so much for your informative reply, Annihilannic.

I can't remember for sure, but I thought I remembered hearing some beeps. As for the cursor keys, I also thought they caused the screen to give "visual beeps" so I stopped pressing them and just used enter in future which also caused these "visual beeps".

 

[jbaker76786]

Oh yeah and your right, I was logged in as root though I don't know what shell it was.