check_nrpe put $ at end of check string - powershell

Question

i've a problem with my powershell nagios script, mounted on a MS Windows Server 2008 64bit, with a NRPE_NT daemon.
I've declared the command like this:
command[check_files]=cmd /c echo C:\nrpe\libexec\check_file.ps1 $ARG1$; exit($lastexitcode) | powershell.exe -command -
I've set ExecutionPolicy as unrestricted
I've restart NRPE_NT Services and declared command on console, like this:
$USER1$/check_nrpe -H $HOSTADDRESS$ -t 60 -c check_files -a $ARG1$
Now, why if i run it locally, it works good:
C:\>cmd /c echo C:\nrpe\libexec\_file.ps1 C:\nrpe; exit($lastexitcode)| powershell.exe -command -
No file/s present with this string
But if i run it by check_nrpe i receive this output:
'-' was specified with the -Command parameter: no other arguments to -Command are permitted.
In Debug mode, on NRPE.log i can see this:
Running command: cmd /c echo C:\nrpe\libexec\check_file.ps1 C:\nrpe;
exit($lastexitcode) | powershell.exe -command - $
Command completed with return code 0
Why in this way, check_nrpe add a dollar character ($) at end string, derailing the entire control ?
Thanks in advance

Answer 1

I'm not sure if this will help your situation, but I just figured out something in my environment that was causing something similar. Here was my NRPE command comfiguration:
command[foo]=grep file '^pattern$'
Everything was fine until I wanted to add another parameter after the '^pattern$' parameter... that new parameter (at the end of the command-line) would get an extra $ appended to the end.
It seems that NRPE requires $ to be escaped, otherwise it thinks that it's a variable reference and does odd things with it. I was expecting that the quoting would make it so that no escaping was required, but NRPE's configuration files don't follow shell-style quoting rules. So, changing my NRPE configuration to this solved my problem:
command[foo]=grep file '^pattern$$'
Note the double $$ in the revised NRPE command definition.