check if file exists on remote host with ssh

Question

I would like to check if a certain file exists on the remote host. I tried this:

$ if [ ssh user@localhost -p 19999 -e /home/user/Dropbox/path/Research_and_Development/Puffer_and_Traps/Repeaters_Network/UBC_LOGS/log1349544129.tar.bz2 ] then echo "okidoke"; else "not okay!" fi
-sh: syntax error: unexpected "else" (expecting "then") 

Answer 1

You're missing ;s. The general syntax if you put it all in one line would be:

if thing ; then ... ; else ... ; fi

The thing can be pretty much anything that returns an exit code. The then branch is taken if that thing returns 0, the else branch otherwise.

[ isn't syntax, it's the test program (check out ls /bin/[, it actually exists, man test for the docs – although can also have a built-in version with different/additional features.) which is used to test various common conditions on files and variables. (Note that [[ on the other hand is syntax and is handled by your shell, if it supports it).

For your case, you don't want to use test directly, you want to test something on the remote host. So try something like:

if ssh user@host test -e "$file" ; then ... ; else ... ; fi

Answer 2

Can't get much simpler than this :)

ssh host "test -e /path/to/file"
if [ $? -eq 0 ]; then
    # your file exists
fi

Answer 3

one line, proper quoting

ssh remote_host test -f "/path/to/file" && echo found || echo not found

Answer 4

Test if a file exists:

HOST="example.com"
FILE="/path/to/file"

if ssh $HOST "test -e $FILE"; then
    echo "File exists."
else
    echo "File does not exist."
fi

And the opposite, test if a file does not exist:

HOST="example.com"
FILE="/path/to/file"

if ! ssh $HOST "test -e $FILE"; then
    echo "File does not exist."
else
    echo "File exists."
fi

Answer 5

On CentOS machine, the oneliner bash that worked for me was:

if ssh <servername> "stat <filename> > /dev/null 2>&1"; then echo "file exists"; else echo "file doesnt exits"; fi

It needed I/O redirection (as the top answer) as well as quotes around the command to be run on remote.

Answer 6

Here is a simple approach:

if ssh $HOST stat $FILE_PATH \> /dev/null 2\>\&1
            then
                    echo "File exists"
            else
                    echo "File does not exist"

fi