How to capture SFTP transfer if successful from expect - shell

Question

I was lurking on this site for quite awhile now because I am doing an SFTP in a expect/SH script. SSH keygen is not an option for us since we don't have access to the remote server so we're looking into using expect to provide password arg for SFTP.
Here is the script I am working on, and everything is working here except I want to capture or log to an output file if my transfer ("mput") completed successfully. Any advice on what code to put after the "mput" since if I add an expect_out(buffer) after, it is failing.
#!/bin/ksh
DIRROOT=/apps/gen/e2k/sys/bpp
COPYDIR=$DIRROOT/SENT
FILEHASH=TEST.SOME.FILE.*
if [ ! -f $COPYDIR/$FILEHASH ]; then
echo "No File"
fi
# New FTP credential from GIC
FTPSERV=**********
FTPUSER=**********
FTPPWD=**********
FTPDIR=/to-scs
/usr/local/bin/expect -f - <<EOFEXPECT1
#exp_internal 1
set timeout -1
set log [open "/dir/dir1/dir2/MIKETEST.txt" w]
spawn sftp -oPort=10022 $FTPUSER#$FTPSERV
expect "password:"
send "$FTPPWD\r";
expect "sftp> "
send "lcd $COPYDIR \r";
expect "sftp> "
send "cd /recipient \r";
expect "sftp> "
send "mput TEST.SOME.FILE.*\r";
put $log $expect_out(buffer)
close $log
expect "sftp> "
send "bye\r";
expect eof
EOFEXPECT1
if [ $? -eq 0 ]
then
echo "success"
else
echo "fail"
fi

Answer 1

You should be using puts instead of put and i wouldn't rely on $expect_out(buffer) for error checking. Rather use a nested expect statement to trap for common sftp scenarios/errors.
set timeout -1
send "mput TEST.SOME.FILE.*\r";
expect {
#Check for progress, note does not work with all versions of SFTP
#If a match is found restart expect loop
-re "\[0-9]*%" {
set percent $expect_out(0,string)
puts $logf "File transfer at $percent, continuing..."
exp_continue
}
#Check for common errors, by no means all of them
-re "Couldn't|(.*)disconnect|(.*)stalled" {
puts $logf "Unable to transfer file"
exit 1
}
#OK continue
"sftp>" {
puts $logf "File transfer completed"
}
}
Finally, i don't recommend using timeout of -1 (never) as this will lead to a stuck process sooner or later. Rather make us of a timeout value and trap for the possibility of a timeout to occur in the expect block.
set timeout 60
expect {
#Process timed out
timeout {
puts $logf "File transfer timed out"
}
}