I have 100 servers and i need to login to them with ssh from central server using script: i tried below with this i should get the version redirected to the file which will be stored at central server.
#!/bin/bash
CMD='java -version'
while read line
do
ssh -n user@"$line" $CMD >> /pathforoutputfile/outputjava.txt
done < /pathforhosts/hosts.txt
But I am not getting output generated in file /pathforoutputfile/outputjava.txt
That command does in fact write to stderr.
ron@haggis:~$ java -version
openjdk version "11.0.2" 2019-01-15
OpenJDK Runtime Environment (build 11.0.2+9-Ubuntu-3ubuntu118.04.3)
OpenJDK 64-Bit Server VM (build 11.0.2+9-Ubuntu-3ubuntu118.04.3, mixed mode, sharing)
ron@haggis:~$
ron@haggis:~$ java -version 2> foo.txt
ron@haggis:~$ cat foo.txt
openjdk version "11.0.2" 2019-01-15
OpenJDK Runtime Environment (build 11.0.2+9-Ubuntu-3ubuntu118.04.3)
OpenJDK 64-Bit Server VM (build 11.0.2+9-Ubuntu-3ubuntu118.04.3, mixed mode, sharing)
Thus, you should redirect using 2>> instead of >> in
ssh -n sgarole@"$line" $CMD >> /pathforoutputfile/outputjava.txt
One other thing I noticed is that you don't seem to be mentioning the remote host names in /pathforoutputfile/outputjava.txt.
> redirect after done removes the need to manually delete the output file each time the script is being rerun: ...; done <inputfile >outputfile And the host could simply be outputted with printf '%s\n' "$line" in the loop.
ansiblefor server orchestration. see stackoverflow.com/questions/30388361/…set -x.