Question: I have two independently running scripts.
first one lets say script A calculates some values. And i want to echo these values from other script called B. These scripts will not call each other. I have used export keyword but didn't work. How can i do this?

Answer: 
```
 mkfifo /tmp/channel

 process_a.sh > /tmp/channel&
 process_b.sh < /tmp/channel&

 wait

```

Of course you can also just read a single line when you want it.

In bash there are coprocs, which also might be what you want. Random example from [this page](http://wiki.bash-hackers.org/syntax/keywords/coproc)

```
# let the output of the coprocess go to stdout
{ coproc mycoproc { awk '{print "foo" $0;fflush()}' ;} >&3 ;} 3>&1
echo bar >&${mycoproc[1]}
foobar

```

ksh has a similar feature, apparently
You may echo values to files, then the other script may read them. If you want to use it as a parameter for something, use reverse aposthrophe:

```
echo `cat storedvalue`

```

Be careful, if the two scripts are running at the same time, concurrency problems may occur, which can cause rarely appearing, mystic-looking errors.