Questions[command](server)

Say I have a command foo which takes a filename argument: foo myfile.txt. Annoyingly, foo doesn't read from standard input. Instead of an actual file, I'd like to pass it the result of another command (in reality, pv, which will cat the file and output a progress meter as a side effect).

Is there a way to make this happen? Nothing in my bag of tricks seems to do it.

(foo in this case is a PHP script which I believe processes the file sequentially).

I'm using Ubuntu and Bash

EDIT Sorry for the slightly unclear problem description, but here's the answer that does what I want:

pv longfile.txt | foo /dev/stdin

Very obvious now that I see it.

In Linux if you type cat *, you will get something like this:

line1 from file1
line2 from file1
line1 from file2
line1 from file3
line2 from file3
line3 from file3

What I would like is to display a separator among files. Something like this:
line1 from file1
line2 from file1
XXXXXXXXXXXX
line1 from file2
XXXXXXXXXXXX
line1 from file3
line2 from file3
line3 from file3

Is that easily possible with a one-liner easy to type by heart?

I was just poking around in /usr/bin and I found an ELF binary file called [. /usr/bin/[. I have never heard of this file and my first thought was that it was a clever way of hiding a program, possibly a trojan. However it's present on all my CentOS servers and seems to have no manual entry. I can hazard a guess as to what it is but I was looking for a more authoritative answer...

I am playing around with PowerShell scripts and they're working great. However, I am wondering if there is any way to also show all the commands that were run, just as if you were manually typing them in yourself. This would be similar to "echo on" in batch files. I looked at the PowerShell command-line arguments, the cmdlets, but I didn't find anything obvious. Thanks!

I have written a script that I am using to push and deploy a new service to several machines under my control, and in order to execute the process I am using ssh to remotely start the process.

Unfortunately, whenever I use SSH to start the process, the SSH command never seems to return, causing the script to stall.

The command is specified as:

ssh $user@$host "/root/command &"

Whenever I run simple commands, such as ps or who, the SSH command returns immediately, however when I try and start my process it does not return.

I have tried tricks like wrapping my process in a simple bash script that starts the process and then exits, however this also hangs the SSH command (even if the bash script echos a success message, and exits normally).

Does anyone have any insight into what is causing this behaviour, and how I can get the SSH command to return as soon as the process has been started?