Unix command that checks for the existence of a file on another server?

Question

I am reading a list of file names from a config file. using a for loop im selecting each file in the list and then want to search for the file on a remote server.

for file in config
do

**search for file at {remoteserver}**
    returnStatus=$?
    if [ returnStatus = 0 ]; then
         email that file was found.
    fi
done

the search for file at the remote server is the part troubling me. Any help is appreciated,

Have you checked this question? [How to check if a directory exists in a shell script](http://stackoverflow.com/q/59838/1983854). Do that together with `ssh`. — fedorqui, Mar 19 '14 at 11:01

jaypal singh · Accepted Answer · 2014-03-19T12:52:11.867

2

You can do something like:

for file in "${config[@]}"
do
    ssh user@remotehost test -e "$file"
    returnStatus=$?
    if [ $returnStatus -eq 0 ]; then
         email that file was found.
    fi
done

edited Mar 19 '14 at 12:52

answered Mar 19 '14 at 11:08

jaypal singh

74,723
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I get: "return: can only `return' from a function or sourced script". – Tom Fenech Mar 19 '14 at 11:39
@TomFenech I meant to write `exit` not return. Fixed. – jaypal singh Mar 19 '14 at 11:55
The whole script now exits on the first iteration, so this doesn't work either. – Tom Fenech Mar 19 '14 at 12:06
@TomFenech Thanks for reporting feedback. Can you please ellaborate - the script exits on first iteration? – jaypal singh Mar 19 '14 at 12:26
When you are calling `exit`, that exits the whole script running on the local machine, not just the `ssh` part of the script. So the whole script will `exit 0` or `exit -1` on the first iteration of the loop. – Tom Fenech Mar 19 '14 at 12:30

Tom Fenech · Answer 2 · 2014-03-19T14:07:05.097

1

Assuming that

All the files are on separate servers
You want to send the email from your local system

this could be the solution:

for file in "${config[@]}"
do
    exists=$(ssh user@host "if [ -e \"$file\" ]; then echo '1'; else echo '0'; fi")
    if [ $exists = "1" ]
    then
        echo "$file exists"
        #send email
    fi
done

If all the files were on the same remote server, it would make more sense to do the loop within the ssh connection, rather than reconnecting every time.

edited Mar 19 '14 at 14:07

answered Mar 19 '14 at 11:28

Tom Fenech

72,334
12
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Just wanted to thank you for helping in debug the script and getting it fixed. As you can tell, I am not that great with `bash`. Hopefully will get there soon. Appreciate it. +1 – jaypal singh Mar 19 '14 at 13:39

Unix command that checks for the existence of a file on another server?

2 Answers2