Bash Variable losing its value - strange - bash

Question

notice the FTP_PUT_RETVAL. There are two echo commands, the first one shows a value of '0'. The second one shows no value at all. I am running this inside a nightly cron. BASH is GNU bash, version 3.2.25(1)-release (x86_64-redhat-linux-gnu)
My script tells me that the ftp upload was unsuccessful, because FTP_PUT_RETVAL contains no value!
Why is this occuring? How can I change this? What have I done wrong?
#!/bin/sh
#
# Filename: rh5-manager-cron.sh
#
# Purpose: Runs backup.cron, and FTP uploads backup to Linux4
#
# Usage: the program is run with no arguments. This program is
# intended to run from manager cron, and redirection is handled inside the cron
# e.g. 00 1 * * * /u2/app/lbin/rh5-manager-cron.sh > /tmp/log/rh5-manager-cron.log 2>&1
trap signalCaught ABRT EXIT HUP INT PIPE TERM QUIT
signalCaught () {
for file in $FTP_LOG_FILE $TMPF; do
$BIN_HOME/rm_file $TMPF
done
exit
}
if [[ ! -r /u2/conf/ctrl/lettus.sh || ! -r /u2/app/lbin/fsh_sh_lib ]]; then
printf "Cannot source environment.\n" >&2
exit 1
fi
. /u2/conf/ctrl/lettus.sh
. /u2/app/lbin/fsh_sh_lib
#-------------------------------------------------------
# Variables
#-------------------------------------------------------
PRG=${0##*/}
FTPUSER=dummy
FTPPASS=dummy
FTPHOST=192.168.0.3
BACKUPDIR=/backup
FTPBACKUPNAME=Redhat5Backup.tgz
FTPBACKUPFILE=$BACKUPDIR/$FTPBACKUPNAME
LOGDIR=/tmp/log
FTP_LOG_FILE=$LOGDIR/Redhat5FTP.log
SENDLOGS=$C/sendlogs.dat
ZOOT_XML=$C/zoot.xml
TMPF=`mktemp` || exit 1
#-------------------------------------------------------
# Sanity
#-------------------------------------------------------
if ! isValidUser root manager; then
printf "$PRG: Must be run as user 'root' or user 'manager'.\n" >&2
exit 1
fi
if [[ ! -d $BACKUPDIR ]]; then
logger "$PRG: $BACKUPDIR: Not a valid directory" >&2
exit 1
fi
if [[ ! -d $LOGDIR ]]; then
logger "$PRG: $LOGDIR: Not a valid directory" >&2
exit 1
fi
if [[ ! -r $SENDLOGS || ! -r $ZOOT_XML ]]; then
logger "$PRG: E-mail: Files are not readable: $SENDLOGS, $ZOOT_XML" >&2
exit 1
fi
if ! which lftp >/dev/null 2>&1; then
logger "$PRG: lftp: command not found" >&2
exit 1
fi
# e-mail
EMAIL_SUBJECT="Redhat5 FTP PUT"
EMAIL_TO=$(email_to $SENDLOGS)
EMAIL_FROM=$(email_from $ZOOT_XML)
# ftp binary
LFTP_BIN=$(which lftp 2>/dev/null)
#-------------------------------------------------------
# Functions
#-------------------------------------------------------
# calls lftp to upload a file to server non-interactively
ftp_put() {
$LFTP_BIN $LFTP_DEBUG -u ${FTPUSER},${FTPPASS} $FTPHOST <<-EOF
put $FTPBACKUPFILE
pwd
ls $FTPBACKUPNAME
quit
EOF
#^^^^^^^^^^^ leave the above indentation alone
}
main() {
# Backup, and send manager logs
logger "Running backup.cron..."
echo
backup.cron
BACKUP_CRON_RETVAL=$?
logger "Running fsh_sendlogs..."
echo
$SH_HOME/fsh_sendlogs 1
# show ls listing
logger "Here comes a directory listing..."
echo
/bin/ls -l /backup/Redhat5Backup.tgz
echo
# ftp upload
logger "Running ftp upload..."
echo
ftp_put
FTP_PUT_RETVAL=$?
echo " -- debug: Line ${LINENO:-}: FTP_PUT_RETVAL=${FTP_PUT_RETVAL:-}"
}
checkSuccess() {
if [[ "$BACKUP_CRON_RETVAL" -eq 0 ]]; then
echo "Backup was successful."
echo
echo "*********************************"
echo " OK: Backup was successful."
echo "*********************************"
echo
else
echo "ERROR: Backup FAILED! "
echo
echo "*********************************"
echo " ERROR: Backup FAILED! "
echo "*********************************"
echo
fi
echo " -- debug: Line ${LINENO:-}: FTP_PUT_RETVAL=${FTP_PUT_RETVAL:-}"
if [ "$FTP_PUT_RETVAL" -eq 0 ]; then
echo "lftp: ftp file upload complete."
echo
echo "*********************************"
echo " OK: ftp file upload complete."
echo "*********************************"
echo
else
echo "lftp: error ftp file upload not successful."
echo
echo "*********************************"
echo " ERROR: file upload"
echo " NOT successful."
echo "*********************************"
echo
fi
}
email_logs() {
if [[ -z "$EMAIL_FROM" || -z $EMAIL_TO || -z $EMAIL_SUBJECT || ! -r $FTP_LOG_FILE ]]; then
logger "$PRG: One of the variables is not correctly configured" >&2
exit 1
fi
fsh_mail -r "${EMAIL_TO}" -F "${EMAIL_FROM}" -s "${EMAIL_SUBJECT}" -t "${FTP_LOG_FILE}"
return
}
#----------------------------------------------------------------------
# Main Program
#----------------------------------------------------------------------
main | tee $FTP_LOG_FILE
checkSuccess | tee -a $FTP_LOG_FILE $TMPF
cat $FTP_LOG_FILE >> $TMPF
# E-mail ftp log file
logger "Emailing ftp logfile"
echo
email_logs
#eof

Answer 1

The problem is that you are using:
main | tee $FTP_LOG_FILE
checkSuccess | tee -a $FTP_LOG_FILE $TMPF
Because of the piping, the work done in main is done in a sub-shell, and a sub-shell cannot set variables in the parent shell. So, when checkSuccess (which is also run in a sub-shell) goes to look at the results, it sees what was in the parent shell (nothing), rather than what was set in the main function in a sub-shell.
If you dropped the piping, it would start to work.
More reliably, put the call to checkSuccess into the main function. Or use one or the other of these two notations:
{ main; checkSuccess; } | tee $FTP_LOG_FILE $TMPF
( main; checkSuccess ) | tee $FTP_LOG_FILE $TMPF
Note that the { ... } notation requires a semi-colon after the second function which the ( ... ) notation does not require. However, there is one less process involved in the { ... } mechanism, not that it is going to make any measurable difference to the overall performance of this (the FTP time will dominate).