update sftp setup

sftp-server.md

@@ -50,6 +50,21 @@ $ mkdir /sftp/guestuser/incoming
 # set folder ownership
 $ chown guestuser:sftpusers /sftp/guestuser/incoming
 
+# set folder group
+$ chgrp -R sftpusers /sftp/general
+# Give write permission to the group
+$ chmod -R g+w /sftp/general
+
+#setup common folder for a group
+$ groupadd sftp
+$ mkdir /home/sftp
+$ chown nobody:sftp /home/sftp/common
+$ chmod 770 /home/sftp/common
+$ useradd -d /home/sftp/common -g sftp sam
+$ useradd -d /home/sftp/common -g sftp tom
+
+$ chmod g+s /home/sftp/common
+
 # verify ownership
 $ ls -ld /sftp/guestuser/incoming
 drwxr-xr-x 2 guestuser sftpusers 4096 Dec 28 23:49 /sftp/guestuser/incoming