I've searched a lot on the internet but haven't been able to find any useful info this yet. Does PFTP not allow you to run loops like 'IF' and 'WHILE' at all?
If it does, please let me know the syntax, I'm tried of banging my head against it. Annoyingly, PuTTY allows these commands but psftp doesn't seem to even though both are from the same family. I really hope there is a solution to this!
PSFTP isn't a language. It's just an SFTP client. SFTP itself is just a protocol for moving files between computers. If you have SFTP set up on the remote computer then it suggests that you have SSH running (since SFTP generally comes bundled with the SSH server install).
You can do a test in a bash shell script, for instance, to see if the file exists on the remote server, then execute your psftp command based on the result. Something like:
#!/bin/bash
# test if file exists on remote system
fileExists=$(ssh user@yourothercomputer "test -f /tmp/foo && echo 'true' || echo 'false'")
if $fileExists; then
psftp <whatever>
fi
You can stick that whole mess in a loop or whatevs. What's happening here is that we are sending a command test -f /tmp/foo && echo 'true' || echo 'false' to the remote computer to execute. The stdout of the command is returned and stored in the variable fileExists. Then we just test it.
If you are in windows you could convert this to a batch script and use plink.exe to send the command kind of like they do here. Or maybe just plop cygwin on your computer with an SSH and SFTP client and use what's above.
The big take-away here is that you will need a separate scripting environment to do the loop and run psftp based on a test.