Check if rsync command ran successful

Question

The following bash-script is doing a rsync of a folder every hour:

#!/bin/bash
rsync -r -z -c /home/pi/queue [email protected]:/home/foobar
rm -rf rm /home/pi/queue/*
echo "Done"

But I found out that my Pi disconnected from the internet, so the rsync failed. So it did the following command, deleting the folder. How to determine if a rsync-command was successful, if it was, then it may remove the folder.

Solution 1

Usually, any Unix command shall return 0 if it ran successfully, and non-0 in other cases.

Look at man rsync for exit codes that may be relevant to your situation, but I'd do that this way :

#!/bin/bash
rsync -r -z -c /home/pi/queue [email protected]:/home/foobar && rm -rf rm /home/pi/queue/* && echo "Done"

Which will rm and echo done only if everything went fine.

Other way to do it would be by using $? variable which is always the return code of the previous command :

#!/bin/bash
rsync -r -z -c /home/pi/queue [email protected]:/home/foobar
if [ "$?" -eq "0" ]
then
  rm -rf rm /home/pi/queue/*
  echo "Done"
else
  echo "Error while running rsync"
fi

see man rsync, section EXIT VALUES

Solution 2

Old question but I am surprised nobody has given the simple answer:
   Use the --remove-source-files rsync option.
I think it is exactly what you need.

From the man page:

--remove-source-files   sender removes synchronized files (non-dir)

Only files that rsync has fully successfully transferred are removed.

When unfamiliar with rsync it is easy to be confused about the --delete options and the --remove-source-files option. The --delete options remove files on the destination side. More info here: https://superuser.com/questions/156664/what-are-the-differences-between-the-rsync-delete-options

Solution 3

you need to check the exit value of rsync

#!/bin/bash
rsync -r -z -c /home/pi/queue [email protected]:/home/foobar
if [[ $? -gt 0 ]] 
then
   # take failure action here
else
   rm -rf rm /home/pi/queue/*
   echo "Done"
fi

Set of result codes here: http://linux.die.net/man/1/rsync

Comments

[user1670816]

Should I use if [ "$?" -eq "0" ] or if [[ $? -gt 0 ]] ? Because the latest is the resultcode regarding the rsync documentation.

[Benjamin Sonntag]

both work fine. [ is a shell syntax, [[ is bash-specific, and the first compare the exit code to 0, the other one to non-zero, and the if is reverse, so both are working fine and doing exactly the same here \o/