Dreamersedge Blog

some useful vi commands

i  - insert text

I - insert line before cursor

dd - remove entire line

x - remove single character

Esc (key) - To return to command mode after in edit mode.

:x - exit and save

:q - exit and don't save

If you had a file structure like

dir1
dir2
dir3
folder

And you wanted to copy all the three directories (and their contents) dir1, dir2 and dir3 into the directory called folder, you use the command

cp -rv dir* folder

Note: I like to use the "v" switch here, meaning verbose, so I know how the copy is progressing

If you then wanted to remove the directories from their original location, you could use the command

rm -r dir*

Use the command

rm -r <directory name>

on linux, use the command

sftp (or ftp) SERVER_NAME

to view the local directory list use lls

to view the remote directory list use ls

to move a file from local to remote use put filename

to move a file from remote to local use get filename

Note: local is the system you ran sftp (or ftp) from, and remote corresponds to SERVER_NAME

run sudo apt-get install mencoder

then use the command  mencoder infile.wmv -ovc xvid -oac mp3lame -xvidencopts fixed_quant=4 -o outfile.avi

fixed quality can range from 1(high) to 31(low). I found 4 was good enough without making the file size too large.

You can then play it using mplayer with the command mplayer outfile.avi

But I found that this cropped the video during playback. Upon inspection in Windows Medai Player I found that the file had been created fine and there was no cropping. I'm sure there is a command line option for mplayer to avoid this but I can't be bothered to look at the moment.

Exit steam

Insert the disk into the cd drive

Run  "C:\Program Files\Steam\Steam.exe" -install E:

Edit this command line as necessary.

Use the command

quota

Use the command

uname -a

Note: uname -m gives a simplified output

To overlay two plots we use the Show command. In this example I will overlay a plot of a function, f(x), and a list of datapoints.

p1 = Plot[f[x], {x, 0, 5}, PlotRange -> {-1, 1}, PlotStyle -> {Blue, Thick}];
p2 = ListPlot[plotlist, PlotMarkers -> {"image"}];
Show[p1, p2]

Where f(x) is the function and plotlist is the list of x,y coordinates of the datapoints. The placeholder "image" is for the image shown in the plot below. The result is