Shell programing

[Igor Sovin]

I have text file with several strings in it.
for example
more 123.txt
aa
bb
cc
dd

I need to make script that could read these strings from 123.txt and write them in another txt file.

[RAC_1]

cp 123.txt what_ever.txt

[Muthukumar_5 · Accepted solution]

while read line; do

echo ${line}

done < inputfile >

You can copy all the contents if you are not going to any changes as,

cp

--
Muthu

[Peter Godron]

Igor,
if you insists on a script:
#!/usr/bin/sh
while read record
do
echo $record >> output.txt
done < 123.txt

[Muthukumar_5]

Are you going to do any shell program or changes in content? or simply that contents itself?!

More ways to simply copy the file contents to new.

cat file > newfile

--
Muthu

[Igor Sovin]

I have the following script:

for i in 1 2 3
do
command ${variable}
done

I need to get aa then bb and cc from 123.txt and put it into my script instead of variable.
How to do that?

[Muthukumar_5]

Use like:

for i in 1 2 3
do
while read variable;
do
command ${variable}
done < 123.txt
done

That is it.

--
Muthu

[Muthukumar_5]

Can you just ellaborate your requirement to give effect script solution!? In the for loop you are not using i variable anywhere.

Post requirement as:

1) input
2) expected output from input

--
Muthu

[Igor Sovin]

the problem is :

1. I have txt file containing list of remote hosts.
host1
host2
host3 etc
2. I need to do script that reads host1 from txt file and ssh to host1 do the command then exit from host1, and this action must be done for all hosts ( host2, host3.. etc).

[Muthukumar_5]

1. I have txt file containing list of remote hosts.
host1
host2
host3 etc
2. I need to do script that reads host1 from txt file and ssh to host1 do the command then exit from host1, and this action must be done for all hosts ( host2, host3.. etc).

>>>>>>>>

Simply as,

put all hosts in > hosts file. So host1,host2 and etc are in hosts file.

while read host;
do
ssh @${host} 'command'
done < hosts


If you don't want to specify the hostname then,

while read host;
do
ssh ${host} 'command'
done < hosts

will do that.


PS: Hope you have set key transaction between hosts for not asking password. Else it will ask password.

--
Muthu

[Igor Sovin]

let me try..

[Igor Sovin]

I've created two files

root@lev /Ignite_Bckp>more test.sh
while read host;
do
ssh ${host}
done < hosts_test.txt

and file containing hosts (in the same dir)

root@lev /Ignite_Bckp>more hosts_test.txt
adam
kate

when executing script test.sh I get error:

root@lev /Ignite_Bckp>chmod +x hosts_test.txt
root@lev /Ignite_Bckp>./hosts_test.txt
./hosts_test.txt: adam: not found.
./hosts_test.txt[2]: kate: not found.

[Hein van den Heuvel]

You reversed the files and are trying to exectue the data (.txt) file.

Try:

chmod +x test.sh
./test.sh


Also... I generally preferr to keep the parameter out of the script file. You your case that means removing the "< node_test.txt" fromt eh .sh

The activate the shell script providing whatever data is appropirate at the moment, possibly even entering lines manually:

./test.sh < node_test.txt

Hein.

[Peter Nikitka]

Hi,

a simple 'ssh' will leave stdin open, so a successful connection will read all but the first value of the loop.
Use:

while read host
do ssh -n $host
done

mfG Peter

[Patrice Le Guyader]

Demat,

Try to enable the public key mechanism.

Look at this procedure and check for the following lines in sshd.conf file :
RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile ~/.ssh/authorized_keys
These lines should be uncommented.

After this you'll be able to do : sftp/scp/ssh between this hosts without password asking.

Another possibility for shell scripting ;
#!/sbin/sh
for SERVER in `cat hosts.txt`
do
ssh $SERVER < command 1
command 2
command n
EOF
done

Hope this help
Kenavo
Pat

[Jannik]

#!/usr/bin/ksh
# use file /tmp/host.list
# file name is : xxxxx

for i in $(cat /tmp/host.list)
do
echo "do something on : $i"
ssh root@$i "command;command"
done

[Igor Sovin]

I'm a novice in shell programming.
Thanks to all for advices. My scrips works fine now.

[Arunvijai_4]

Hi Igor,

You can close this thread now.

-Arun

[Igor Sovin]

have found a solution to this question as seen in the comments below.