C Shell Scripting

Shell Programming and Scripting
1

I am new to Linux and have just started performing Gaussian calculations for a new department created at my work.
I am interested in creating some small scripts to complete some of the routine tasks.
I have created a file based on an old BASH file but it is having issues.

#!/bin/csh
name=$(1%.*)
formchk "%1" "%name.fchk"

This is a test script to test if I could script and it failed misserably.
I am trying to take a file "filename.chk" and run a formchk function that would create a new file "filename.fchk"
formchk is a function of gaussian that required a *.chk input and a named output file. i am trying to make this file univeral for all filenames that would be submitted to it. If this works I will add additional maniputation as needed.
I ran "chmod +x" on the script and executed with "./"
The error i received was "invaid varialbles"

any assistance would be greatly appreciated.
Thanks!!!

2

Hi, is there a reason you are using csh? Most people on this forum -me included- would suggest you save yourself a headache and switch to a bourne shell derivative, like sh, ksh, bash..
http://www.faqs.org/faqs/unix-faq/shell/csh-whynot

3

More reading, as long as you have a choice: Csh Programming Considered Harmful

P.S. I re-read your OP and saw you based this on a bash script. I would suggest you continue to use bash as syntax will most likely be different with csh anyway so if you are following a bash example
I would expect you'll have fewer porting issues sticking with bash.

4

Thanks for the info, I will read up on csh.
I do not have BASH on this machine, or have not located it.
I am very new to scripting (this is my first script), i understand that syntax will be differrence the difference shells, does anyone have a suggestion on how to complete the task mentioned on the first post?
If bourne is on all machines then I am definately okay with using bourne, but I don't know where to start.
Thanks again.

5

I think you are looking to run a script by passing it a filename.chk file, which is then passed to a program that creates a filename.fchk file?

#!/bin/ksh

#  $1 is the first argument passed in.  Expected to be a .chk file.  The string operations
#  used here strip off the period and the extension.
filename=${1%.*}

# Double quotes preserve spaces in case filename has spaces.
# Remove "print" below when ready to run.  With "print", it will show you the command line that will be run.
print formchk "${1}" "${filename}.fchk"

exit 0

This is drastically lacking in error checking, but maybe it will get you started.

Cheat sheet on string operations: The Linux Documentation Project

6

Then use dash or ksh, or even sh if it's a POSIX shell (which it is on most systems).

7

Any even slightly UNIX system ought to have a bourne shell somewhere, often /bin/sh. By comparison, very few have csh these days. Nothing stops someone from installing one later of course.

This ought to work in any basic-functionality bourne shell. It will obliterate your $1 $2 ... variables though, which is why we save VAR for later.

VAR="$1"
IFS="."
set -- $VAR

formchk "$VAR" "${1}.fchk"