Question

I need to execute a script on a remote server over ssh, I can’t locate the script as a file on the remote server nor create files during the script process.

The script checks for a non existent or zero byte file, and if exists, checks if is outdated.

I’ve followed a thread here on SO and tried this:

myvar=$(ssh user@server <<EOF
myfile=/mnt/file.csv
if [ -s $myfile ]; then
   filedate=$(stat -c %x $myfile|grep '[0-9\-]*' --max-count=1 -o);
   yesterday=$(date --date 'now -1 day' --iso-8601);
   if [ $filedate < $yesterday ]; then
     echo '1 '$yesterday;
   else
     echo '0 ok';
   fi
else
   echo $(date --iso-8601);
fi
EOF
)

sadly, the pipe appears to be truncating the string or something, because the script returns

stat: too few arguments

maybe just cannot use “myfile” var declaration. Any suggestions?

Thanks in advance.

—- Edit: Clarifying answer:

keber-laptop:~ keberflores$ echo $myvar

keber-laptop:~ keberflores$ myvar=$(ssh user@server <<EOF
> myfile=/mnt/file.csv
> if [ -s \$myfile ]; then
>    filedate=\$(stat -c %x \$myfile|grep '[0-9\-]*' --max-count=1 -o);
>    yesterday=\$(date --date 'now -1 day' --iso-8601);
>    if [ \$filedate < \$yesterday ]; then
>      echo '1 '\$yesterday;
>    else
>      echo '0 ok';
>    fi
> else
>    echo '1 '\$(date --iso-8601);
> fi
> EOF
> )
Pseudo-terminal will not be allocated because stdin is not a terminal.
user@server's password: 
keber-laptop:~ keberflores$ echo $?
0
keber-laptop:~ keberflores$ echo $myvar
1 2011-10-22

—- Edit: calling inside perl:

my $myvar = qx'ssh user@server <<\'EOF\'
myfile=/mnt/file.csv
if [ -s $myfile ]; then
   filedate=$(stat -c %x $myfile|grep \'[0-9\-]*\' --max-count=1 -o);
   yesterday=$(date --date \'now -1 day\' --iso-8601);
   if [ $filedate < $yesterday ]; then
     echo \'1 \'$yesterday;
   else
     echo \'0 ok\';
   fi
else
   echo \'1 \'$(date --iso-8601);
fi
EOF
';
print $myvar;

Answer 1

You need more escaping to get this to work. bash is going to evaluate the variables, etc in the here-file locally, then the result of that will be evaluated on the remote server.

In particular, your $myfile is probably evaluating to an empty string when the here-file is being evaluated, causing the stat to not have a file argument.