Shell Programming and Scripting

Hi,

I want to write a shell script to make sure all the instruction is executive in flow.
eg.
I want my shell script to run finish this two progress first:

Code:

./program input_file_1.txt > input_file_1.txt.out &
./program input_file_2.txt > input_file_2.txt.out &

After then, only run the following command by using the output result from the above progress:

Code:

cat *.txt.out > input_file.final

Below is the content of the shell script that I wrote:

Code:

#!/bin/sh
./program input_file_1.txt > input_file_1.txt.out &
./program input_file_2.txt > input_file_2.txt.out &
cat *.txt.out > input_file.final

Unfortunately, when I running the shell script above. It will automatic execute the "cat *.txt.out > input_file.final". Even though my "./program input_file_X.txt > input_file_X.txt.out &" is still running. End up, my "input_file.final" is empty since the first two progress is still running and without produce any output file yet

Does anybody got any idea how to make sure the above shell script will start running "cat *.txt.out > input_file.final" only when the first two progress is run finish.

Thanks for any advice.

You have not said what shell you are using but all modern shells have a wait builtin which will do what you want.

Here is the relevant section from the bash manpage.