shell scripting help

[UndergroundX]

i was reading on shell scripting and i understand it and kind dont. I wanted to make a script that automatically converts .avi into mpeg. I use a program called tovid which is all command line here is the command you would type

tovid -wide -ntsc -in (your video here) -out _encoded

how would you make that into excutable script. is this somewhat on how you would do it

$
#
# conerting avi into mpeg
#
echo tovid -wide -ntsc -in some video.avi -out _encoded
clear
?

Am i close or at all. Alittle lost. Appreciate the help.

Thanks

[oz]

UndergroundX, I've moved this to the programming & scripting forum because you're more likely to get help here.

Good luck with it...

[Cabhan]

Right. Well, a single command, you can obviously execute on your own from the command line. But you could put it into a script for fun, or if you wanted to automatically run it on every AVI, or anything like that.

So let's look at your script so far:

Your first line invokes the echo command with a bunch of arguments. However, all that echo does is print something to the screen. You don't want to echo the command, you want to actually want to run it. In a script, the actual command run is the first entry in a statement. A statement is either semicolon-terminated or newline-terminated. So in your script, you have two statements (the echo, and the clear).

How can you change from printing out the command to actually running it?

Also, what are you lost on? If you have a specific question, it will help us help you.

[devils casper]

tovid is a script having bunch of commands that convert avi. to .mpeg. and you are just adding a few more commands before and after calling tovid script in your own script.

I would suggest you to start from here : linuxcommand.org and learn a bit about scripting stuff. You will start creating your own scripts pretty soon.

[UndergroundX]

Oh ok. cause i was reading on howto set it up and it all looks confusing i mean if you mess up just a single line of text the whole script is ruined. Anyways i need help with how to properly make the script. I know from what i inserted was wrong. I wanted someone to help me correct it so that i can execute it say when i wanna convert some video.avi to mpeg all i have to do is. ./script and then thats it. #!bin/bash or sh does that have to be in there at all. If not how come it doesnt have to be?

[devils casper]

As I have suggested earlier, check linuxcommand.org. You will learn a lot of stuff from there.
Do post back after reading first 3-4 chapters.

[Cabhan]

I would also suggest reading:
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html

That guide will also answer your question about the shebang line (the "#!" line).

[sc0rpi0n]

Hey there,

As everyone has pretty much already stated is read up on basic scripting and you'll definitely get it. It's quite simple if you first think about the logic behind it and then use the appropriate commands to make your script work.

For example on your script something like this would work, of course this all depends on _how_ you want your script to work...

Script: myscript

#!/bin/bash

# Command syntax: myscript <avi file>
tovid -wide -ntsc -in $1 -out _encoded

or process all avi folders in current directory...

#!/bin/bash

files=`ls $PWD |grep -i .avi`

for file in $files
do
tovid -wide -ntsc -in $file -out _encoded
done

Good luck.

Scorp