New full version that works

Inner file is run as many times as there are files by the outer file.
This is because Inner file can only rename one file at a time on SFTP
due to limitations of SFTP protocol

inner.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+#This script uploads one file at a time to SFTP server
+#It renames local file first to .tmp
+#It then connects, uploads file, renames it back to no .tmp
+#It then disconnects and delets the local .tmp file 
+
+
+#keeping original name for later step
+filename=$(basename $1 .tmp)
+
+#renaming original local file to FILENAME.tmp to mark it is being processed
+mv $1 $1.tmp
+
+
+#connecting to SFTP using username & ssh keys - not passwords
+sftp USERNAME@IP_ADDRESS << EOT
+cd out
+put $1.tmp
+rename $filename.tmp $filename
+ls -al
+bye
+EOT
+
+#removing the original file
+rm $1.tmp

outer.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# this script just runs the "inner.sh" script as many times as there are files in the directory
+for file in ftpsource/*.csv; do
+  ./inner.sh $file
+done