I am trying to read a file line-by-line in a while loop, and perform some tasks which involves non-interactive SSH to a remote server. The code looks something like this --
Code:
#!/usr/bin/ksh
export myFile=/path/to/my/file.load
while read line
do
do something
## Adding the SSH key for non-interactive ssh
export DISPLAY=junk
export SSH_ASKPASS=/home/subu/add-passphrase.ksh
eval `/usr/bin/ssh-agent | tee -a /tmp/pid.$$.txt`
ssh-add < /dev/null
ssh remoteHost "
if [[ -s someFile ]]
then
ftp -nv myHost << EOF > /dev/null 2>&1
user usrName pwd
prompt
put someFile
bye
EOF
rm -f someFile"
do something else
done < ${myFile}
The problem is after executing the 1st run of the loop perfectly, the read of the while is just not able to read from the file that I've provided as an input to it. Is it happening because of the
Code:
ssh-add < /dev/null
part or the here-doc in the ftp part? Is there an alternate way to do this?
---------- Post updated at 01:07 AM ---------- Previous update was at 01:00 AM ----------
I running this script using KSH in a Solaris box. When I run it using set -x option, the output that I get is
Code:
0< line.from.myFile
read line
.
.
.
.
read line
There is no '0< next.line.from.myFile' before the last 'read line'. This prompts me to conclude that ${myFile} is no longer attached to STDIN, and hence the read fails.
Thanks Chubler_XL! I could finally solve the problem. The issue was not with the indent of the EOF in the here-doc, but the 'ssh-add < /dev/null'. What this did was attach /dev/null to the STDIN and spawn a child-shell as soon as the script ssh-ed to the remoteHost. To avoid this, I altered the script as below --
Code:
#!/usr/bin/ksh
export myFile=/path/to/my/file.load
while read line
do
do something
## Adding the SSH key for non-interactive ssh
export DISPLAY=junk
export SSH_ASKPASS=/home/subu/add-passphrase.ksh
eval `/usr/bin/ssh-agent | tee -a /tmp/pid.$$.txt`
ssh-add < /dev/null
runMode=1
ssh remoteHost exec /usr/bin/ksh -s ${runMode} < "/home/subu/SSHInstructions.ksh"
do something else
done < ${myFile}
The file '/home/subu/SSHInstructions.ksh' contained --
Code:
runMode=$1
if [[ ${runMode} -eq 1 && -s someFile ]]
then
ftp -nv myHost << EOF > /dev/null 2>&1
user usrName pwd
prompt
put someFile
bye
EOF
rm -f someFile
How does this help? This actually spawns a child-shell first and then attaches /dev/null to the STDIN of the child-shell, thereby leaving the STDIN of the parent shell as it was.
P.S. - the reason for lack of indentation in the SSH instructions is that it has a tendency to collapse all the indentations (tabs, blank-lines etc.) into white-spaces, leading the shell to interpret the whole thing as a single command-line.
Greetings.
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