Shell Programming and Scripting

I'm extremely new to shell scripting so I apologize for the crudeness of my descriptions. I am editing a script that will write files (e.g. Job0_A.com, Job1_A.com, etc.) and then run them through a program called gaussian (computational chemistry program). The script will then take the output files (e.g. Job0_A.log, Job1_A.log, etc.) and run them through a fortran program to do further optimizations. Since I am on a multi-user cluster, I have edited the script to run batch files. It seems to have worked but there is a problem. The script will not wait until the .log file has been created (I am running large systems so it make take several hours for the .log to be created) and will just go on to the next job. How do I make the script wait until

Code:

ls | grep 'Job'$num'_A.log >& /dev/null

is true? Also, when I run the script I get a file called $ with nothing in it. I searched the script to see if I made a mistake that would cause this but I can't find anything.

One easy way is to have the first process create the file in a different path (name, extension, directory) of the same device, and when done and happy, move it so the next process can start. Usually, scripts start the next process right then, so it is not an issue. If the second process needs multiple processes from the first set of processes, it waits for one file and then waits for the next until all are present. Serial data can even be piped from one program to the next without a flat file, or with the flat file produce by tee on the pipeline. However, scientific array problems want to mmap() the whole file into VM for processing, so pipes need not apply!

Code:

#!/bin/bash
 
while :
do
 if [ -f file1 -a -f file2 -a -f file3 ]
 then
  break
 fi
 
 sleep 1
done
 
process2 file1 file2 file3

Thanks for the reply! Again, I'm very new to this so I apologize, but I don't understand some of the code. In

Code:

if [ -f file1 -a -f file2 -a -f file3 ]

what does the -f and -a mean? Also is the "1" after sleep the number of seconds until the loop restarts?
I only need two files from the first process and they must both be present at the same time for the next process to work. Do you think this would work:

Code:

ls | grep 'file1' 'file2' >& /dev/null
while:
do 
    if ( $status == 0 )
    then
       break
    fi
    sleep 1
done

process2 file1 file2

Again, I thank you for your help!

That 'if' looks a lot like C shell, what shell are you using?

-f is file from man test, as '/bin/[' is a hard link to '/bin/test' and some shells mimic it with builtins.

Okay thanks! I'll give it a try.

It is the C shell. The script I am editing has /bin/csh -f.

That would have been nice to know. The code you've been given so far will not work in C shell.