Hello,

I'm trying to assign a numeric value that is returned from one of my programs to a variable in tcsh. I want to do:

@ r10 = './my_prog file 35'

where ./my_prog file 35 returns a decimal value, but this doesn't work. How do I achieve the desired result?

Janet

What you are asking is for a child (called) process to return info to parent (master) program. The construct of unix does not allow for this as whatever is learned by the child does not have a way to naturally pass to parent; the reverse is ok, and is often accomplished with an EXPORT command.

Searching this forum will probably provide several creative solutions. Some are:
(a) return the value by way of the exit error parameter of the child back to the parent
(b) have the child write the data to a temporary file that the parent can then read

Hi.

Keeping in mind that:
We can use the following little script:

#!/usr/bin/env tcsh

@ result = 31416 * 2
echo $result

exit

#!/usr/bin/env tcsh

# @(#) s1       Demonstrate script result capture.

echo
echo "(Versions displayed with local utility version)"
sh -c "version >/dev/null 2>&1" && version tcsh
echo

echo " Nonce script:"
cat -n t1

echo
echo " Results:"
set var1 = `./t1`
echo " var1 is $var1"

exit 0

% ./s1

(Versions displayed with local utility version)
tcsh 6.13.00

 Nonce script:
     1  #!/usr/bin/env tcsh
     2
     3  @ result = 31416 * 2
     4  echo $result
     5
     6  exit

 Results:
 var1 is 62832

If by "returned" you mean "written to standard output", then simply use backticks to capture the output of my_prog:

@ r10 = `./my_prog file 35`

Thanks for the really helpful posts.

A combination of writing only ints to standard output from my program and the use of backtics has cracked my problem.

Thanks for spending the time to explain & provide a solution too - much appreciated.