How to make the scp retry till it succeds in case of a failed attempt?

Question

I have a perl script written in Server B to scp a file periodically for every hour from Server A to Server B. The problem is sometimes the scp fails for that particular hour because of some issues on the server B. I want the scp to keep retrying until it succeeds whenever this happens.

The script is:

$soc_scp=`scp -r user\@some_ip:\/home\/hbase\/hourly\/$datehr\.tar\.gz \/home\/hbase\/hourly\/$datehr\.tar\.gz`;


$echo_soc=`echo $?`;

if($echo_soc != 0)
{
$soc_scp=`scp -r user\@some_ip\:\/home\/hbase\/hourly\/$datehr\.tar\.gz \/home\/hbase\/hourly\/$datehr\.tar\.gz`;
}

I have not specified the ip for security reasons.Any help would be much appreciated.

Answer 1

Instead of the backticks, try calling scp with system(). That captures scp's exit status instead of its output. Then you can check it and retry if it was nonzero.

sleep 1 while system "scp -r user\@some_ip:/home/hbase/hourly/$datehr.tar.gz /home/hbase/hourly/$datehr.tar.gz";

This will try scp forever at 1s intervals until success.
To limit the number of tries to 10:

my $tries = 0;
while (system "scp -r user\@some_ip:/home/hbase/hourly/$datehr.tar.gz /home/hbase/hourly/$datehr.tar.gz") {
    last if $tries++ > 10;
    sleep 1;
}