how to check a file on remote machine

[roberto salvatori]

hi all,
in a script file, before making a ftpfro a machine 1 to machine 2, i must insert the control if a file exist (ever in a machine 2). which is the best way to control this?
is it better to make a ftp and import on a machine 1 and check if the size is > 0 or create a telnet connection and check the result of the control?
thanks in advice

[Zeev Schultz]

Use remsh $HOST "(file $FILE) or "ls file".

Zeev

[roberto salvatori]

i've seen in a previous messages that is possible to check the remsh return code. is it right?

[Umapathy S]

rsh, remsh returns the value of their execution and not the remote command return value.

if remsh fails to setup its connection with remote host, then it will flag a failure.

Even if the remote command fails, remsh will always return success only.

To check the remote command status, you may need to redirect the value to a file and check the file.

check the man page for remsh on return value section.

HTH
Umapathy

[Zeev Schultz]

See that one (for Solaris).
http://www.netsys.com/sunmgr/1997-12/msg00120.html.However I tried and it didn't
work on hp-ux.Should be some way to save remote "$?" - exit status and read it.

Zeev

[Massimo Bianchi]

Hi,
usually i don't test the ret code for the existance of file, but i count the number of lines in the output and print them.


So

COUNT=$(remsh host -l root -n "ls file" | grep -v "not found" |wc -l )

if $COUNT = 0 -> file does not exists

HTH,
Massimo

[Zeev Schultz · Accepted solution]

This one works:

Q: I've been trying to write a script to run a command on a remote machine and determine if the command was successful. However, it always returns 0 regardless of the command's success. What's wrong?

A: Actually, your script is working OK, but the problem is that it isn't what you want. The return code of 0 comes from remsh where 0 means a connection was successful and non-zero means that no connection was possible. remsh does not monitor any command(s) that are sent.

So the solution is to ask the remote system to return the results of executing the remote command. For example:
remsh mymachine 'll /tmp >/dev/null 2>&1 ; echo $?'
will return 0 (ll /tmp was successful) whereas:

remsh mymachine 'll /temp >/dev/null 2>&1 ;echo $?'
will return 1 since ll /temp fails (no such directory). Note also that you should usually use remsh's -n option to avoid hangs when encountering a command or login that requires stdin.

Bless Google :)

[roberto salvatori]

thank u so much for all but there is another problem:
if the remote machine who containing the file that i must check is a nt machine? remsh it doesn't work. someone have a solution or ftp is the only way to control?

[Zeev Schultz]

Points should go to Bill Hassel :
I found the trick here:
http://www.interex.org/pubcontent/enterprise/nov01/qabh1101.jsp

Zeev

[Zeev Schultz]

By default,there's no rshd/remshd on win.
Check this link though:
http://www.denicomp.com/rshdnt.htm

[roberto salvatori]

thank u Zeev