Actually the FTP is extremely good at knowing whether a file is newer or not iff you use the Net::FTP Perl client but that should not be necessary if I can depend upon you being truthful about the filename changing everytime. All we have to do is list the remote directory and compare those names to the one found in the destination directory on the local machine. Any files not found should be retrieved and mail should be sent. I already have a Perl script which will do all of the hard work, we just need to add some shell logic.
ftp.sh
--------------------------------
#!/usr/bin/sh
PATH=${PATH}:/usr/local/bin
export PATH
typeset PROG=${0##*/}
typeset TDIR=${TMPDIR:-/var/tmp}
typeset PID=${?}
typeset T1=${TDIR}/X${PID}_1.txt
trap 'eval rm -f ${T1}' 0 1 2 15
typeset SRCDIR="/home/cstephen"
typeset REMHOST="bugs"
typeset DESTDIR="/tmp/cstephen"
typeset U="cstephen"
typeset P="-p secret"
typeset ADDRESS="mmouse@disney.com"
typeset -i STAT=0
# make sure destination directory exists"
if [[ ! -d "${DESTDIR}" ]]
then
echo "Destination ${DESTDIR} does not exist." >&2
exit 1
fi
cd "${DESTDIR}"
STAT=${?}
if [[ ${STAT} -ne 0 ]]
then
echo "Cannot cd to ${DESTDIR}; status ${STAT}." >&2
exit 2
fi
#Get a list of files in directory ${DIR} on remotehost {REMHOST}
#Login as user ${U} using password ${P}.
#If a .netrc file is located on the client then no passwd is needed.
ftpget.pl -h ${REMHOST} -l ${U} ${P} -L '' -d "${SRCDIR}" > ${T1}
STAT=${?}
if [[ ${STAT} -eq 0 ]] # dirlist okay
then
if [[ -s ${T1} ]]
then
typeset FNAME=""
cat ${T1} | while read FNAME
do
if [[ ! -f ${FNAME} ]]
then
ftpget.pl -h ${REMHOST} -l ${U} ${P} -d "${SRCDIR}" "${FNAME}"
STAT=${?}
if [[ ${STAT} -eq 0 ]]
then
echo "New File: ${FNAME}" | mailx -s "New File" ${ADDRESS}
else
echo "Failed to get ${FNAME}; status ${STAT}" >&2
exit ${STAT}
fi
fi
done
fi
else
echo "${PROG} dirlist failed; status ${STAT}" >&2
fi
exit ${STAT}
-------------------------------
That should do it if I haven't made any typo's. You can add a patterm to the ftpget.pl -L argument to match only certain patterns. e.g -L 'Data*.txt'. Using Perl is a much better choice because you get error checking for free -- something that is very tedious in the shell. Note that you can also setup a .netrc file on your end and you don't need to pass the password. Man .netrc for details. If you want to do this more secure there is also a Net::SFTP module. You can then make a cron wrapper script for this and you are done.
Here's the perl piece, ftpget.pl; the above script assumes that you install it in /usr/local/bin. I suggest that you invoke it as ftpget.pl -u for full usage because you may want to set binary or ASCII mode for the gets.
If it ain't broke, I can fix that.
