I have gone through the following guide to set up an SSIS package to retrieve a text file located on an SFTP server:
https://www.mssqltips.com/sqlservertip/3435/using-sftp-with-sql-server-integration-services/
To summarize, the SSIS package executes PSFTP.exe (A PuTTY tool) which takes the necessary credentials to connect to the server. It also takes a batch file that it executes after connecting. This batch file contains the commands to retrieve the desired text file. To start from the guide, it simply contains a cmd command to change directory, and a get command to retrieve the file:
cmd DataDump
get TeleMarketingResults.txt
All of this works fine.
The issue arises when I try to make this batch file logic more complex as it does not seem to recognize basic keywords. For instance, I would like to modify it to retrieve the most recent file, so I tried adding this:
for /f %%i in ('dir /b/a-d/od/t:c') do set LAST=%%i
echo The most recently created file is %LAST%
but then I get these errors:
psftp: unknown command "for"
psftp: unknown command "echo"
If I execute the batch file manually in a local directory, it works. The issue only occurs when passing it as a parameter to PSFTP.exe. Why is this?
psftp script file can contain psftp commands only. for, set or dir are not psftp commands.
There's hardly any reasonable way to retrieve latest file using psftp. You would have to do it in two steps. First to retrieve listing and store it to a file. Then parse that file using some smart batch file commands to find the latest files. And then run psftp again to download that file. It is cumbersome and ineffective as it requires two connections.
You better use a more powerful SFTP client. For example it's trivial with my WinSCP SFTP client. See