Bash reading from file and parsing each line [duplicate] - linux

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This question already has an answer here:
Loop only iterates once with `ssh` in the body [duplicate]
(1 answer)
Closed 8 years ago.
I need to manage updates of a particular software on several customers' linux servers. The updates are provided by sending .tar.gz files to each server and inflating it overwriting the old software files.
I've put the customers' server list in a txt file like this:
user1#customer-server-1-address:22:/path/to/software/server1:NULL:Customer1name
user2#customer-server-2-address:2222:/path/to/software/server2:/etc/vpnc/client1.conf:Customer2name
user3#customer-server-3-address:22:/path/to/software/server3:NULL:Customer3name
Char ":" acts as field separator; field 1 is the server address, 2 is port, 3 is path to software, 4 is used to tell if a VPN tunnel is to be enabled first, 5 is customer name.
I've managed to create the following script:
#!/bin/bash
[...]
while IFS=':' read -ra array; do
if [ "${array[3]}" != "NULL" ]; then
echo
echo "### USING VPN CONF '${array[3]}' FOR SERVER '${array[0]}'... ###"
sleep 1
#vpnc ${array[3]}
TUNNEL1=$(ifconfig | grep -o eth0)
TUNNEL2='eth0'
if [ "$TUNNEL1" = "$TUNNEL2" ]; then
echo "### TUNNEL IS UP ###"
scp -P${array[1]} $FILENAME.gz ${array[0]}:${array[2]}
scp -P${array[1]} $FILELIST ${array[0]}:${array[2]}
ssh -p${array[1]} ${array[0]} 'cd '${array[2]}' && cat '${array[2]}'/'$FILELIST' | cpio --quiet -H ustar -o -0 -L -F '${array[2]}'/'$BACKUP_FILENAME
ssh -p${array[1]} ${array[0]} 'gzip '${array[2]}'/'$BACKUP_FILENAME
ssh -p${array[1]} ${array[0]} 'tar -C '${array[2]}' -xf '${array[2]}'/'$FILENAME.gz
ssh -p${array[1]} ${array[0]} 'cd '${array[2]}' && mkdir -p '$REMOTE_BACKUP_DIRECTORY' && rm -f '$FILELIST' && mv -f '$BACKUP_FILENAME.gz $REMOTE_BACKUP_DIRECTORY
echo "### SERVER '${array[0]}' UPDATED ###"
#vpnc-disconnect
sleep 1
else
echo "### VPN ERROR IN SERVER '${array[4]}' ###"
fi
else
echo
scp -P${array[1]} $FILENAME.gz ${array[0]}:${array[2]}
scp -P${array[1]} $FILELIST ${array[0]}:${array[2]}
ssh -p${array[1]} ${array[0]} 'cd '${array[2]}' && cat '${array[2]}'/'$FILELIST' | cpio --quiet -H ustar -o -0 -L -F '${array[2]}'/'$BACKUP_FILENAME-${array[4]}
ssh -p${array[1]} ${array[0]} 'gzip '${array[2]}'/'$BACKUP_FILENAME-${array[4]}
ssh -p${array[1]} ${array[0]} 'tar -C '${array[2]}' -xf '${array[2]}'/'$FILENAME.gz
ssh -p${array[1]} ${array[0]} 'cd '${array[2]}' && mkdir -p '$REMOTE_BACKUP_DIRECTORY' && rm -f '$FILELIST' && mv -f '$BACKUP_FILENAME-${array[4]}.gz $REMOTE_BACKUP_DIRECTORY
echo "### SERVER '${array[4]}' UPDATED ###"
echo
fi;
done < "$CUSTOMER_SERVERS_FILE"
$CUSTOMER_SERVERS_FILE is the container file as described earlier, $FILENAME.gz is the update package,
$FILELIST is the list of the files to update. Other variables set for other purposes.
Problem is, this whole thing is effectively running only for the first customer in my $CUSTOMER_SERVERS_FILE. The lines above the first are being skipped, and I can't tell why. Any hints? Thank you.
EDIT: As an answer to the duplicate objection, being the script rather large I didn't think of any link between the while and ssh objects. I was rather thinking more of a syntax error. However, I can still delete the question if asked to do so.

Answer 1

This happens because your while read loop and ssh both read from stdin.
You can fix it by using /dev/null as ssh's stdin:
ssh host cmd < /dev/null