OK, I'm bracing myself for some flack by asking this (I've just read dozens of posts around this subject and many enquirers got short change on occasions) but I want to know what I am doing wrong.

I am trying to understand how to write shell scripts for the NIT.

My reading and understanding led me to do the following:

In xTerm without changing directories.
Create a file with two lines by doing the following...

echo '#!/bin/bash' > test.sh
echo 'echo hello' >> test.sh

I've done an ls and confirmed the existance of the file and vi test.sh to confirm the contents.

Next I issued the command

chmod +x test.sh

to turn it into an executable.

I then tried to 'run' it by typing 'test' (w/o quotes) and I get the ~$ prompt back

I tried test.sh and get:
-sh: test.sh: not found

I tried sh -c test.sh
I tried sh -c test

Nothing!

(I also tried test and test.sh without the chmod command with no difference)

I'm expecting to simply see the word hello.


I repeated the whole process with just sh instead of bash in the first line. This made no difference.

What am I doing wrong?

Just a guess... does /bin/bash exist on your device? If not, try using /bin/sh.

I don't know if sh manually interprets the shebang at the top line and tries to execute it with bash. Maybe -c causes it to do that. If sh test.sh works, then it's probably the lack of bash

i agree, #!/bin/sh and run with ./test.sh

you need to specify the actual path of an executable in linux.

tldp.org is a good site to learn shell scripting. http://tldp.org/guides.html
you may also want to go through ' Introduction to Linux - A Hands on Guide ' before you start scripting.

AhHa! It works with ./test.sh and #!/bin/sh at the top
I don't understand since I am in the same directory as the script but this is what was needed.

I meant to say that I had just read through an 8 page introduction to the bash shell before trying this but it did not cover execution.

http://www.panix.com/~elflord/unix/bash-tute.html

I have also written dozens of scripts on domain_os (a version of Unix) about 10+ years ago. I think as soon as I get back into it some of what I learned will come back (here's hoping anyway) and I'm sure some things will be different that I do remember.

albright gave me the following sample for direct GVM app execution which is what I am working towards.

#!/bin/bash
cd /usr/bin/gvm
./gvm -a sWSF

as you can see, he used bash, I presume sucessfully.

Thanks to all respondants. Do feel free to give any further specific pointers to my goal (launching GVM apps directly) knowing where I am right now. I hope one day to be able to contribute some useful stuff that others will benefit from.

This forum has been an immense help to me and made the difference between giving up in frustration and actually making the tablet into even more that I initially expected.

Cheers!

By default most UNIX-like environments don't have the current directory in the path that the shell searches for a given command. This is a security feature, to prevent fake commands to be dropped into a user's directory where the attacker might have write access, as opposed to one of the system directories where an attacker having write access is less likely. Imagine if the following script was put into your home directory:

The next time you tried to show a file listing using the command 'ls -l', the listing would be showed as expected, followed by everything in the current directory being blown away. Not nice to say the least. HTH

That's funny, I guess I'm dealing with admins all day, so I don't even bother with the more straight-forward explanations. As soon as I saw the 'not found' error, I assumed it was referring to the interpreter. If you've got bash on your tablet, then it should be fine to use it in place of sh, although I'm not sure it gives scripts much of an advantage

There's quite a bit of advanced stuff that would make bash desirable over plain 'sh', but for simple stuff there ain't much difference. I use ksh (korn) for most of my own non-tablet scripting, but that's only because that's what I'm used to from my job, and there isn't much there that couldn't be adapted to work in bash, even if it needed any change at all (they're both bourne-compatible shells after all).

Since sh worked I presume I should continue with this at the begining of scripts?
How would I verify presense of bash? (I certainly have not loaded 'it' deliberatley)

Yes, for a lot of cases, using /bin/sh will be fine except if your script has some really advanced scripting that isn't supported by sh.

On a desktop linux computer, I would always use /bin/sh though

If you really want bash for the tablet, you can get bash2 from the extras repo or bash3 from www.nitapps.com