[SOLVED] How to grep multiple words from a remote file in a SSH command to a target server

How to grep multiple words from a remote file in a SSH command to a target server

I wanted to execute the below command. I have a file with server names.

for i in \`cat /tmp/srv_list\`; do ssh $i "uname -a; uptime;  grep -E "warn|error|failed|issues" /var/log/messages ; echo "======================= "" \>\> /var/tmp/hst.out; done

I couldn't get the above working. The one-liner breaks after the first word in the grep sequence and waits indefinitely.

Output

========

# for i in `cat /tmp/srv_list`; do ssh $i "uname -a; uptime; grep -E "warn|error|completed|issues|rollback" /var/adm/messages/*unix " >> /var/tmp/new.out; done

-bash: error: command not found

-bash: issues: command not found

Access to this computer is prohibited unless authorised

Accessing programs or data unrelated to your job is prohibited

Solution

Bash is able to serialize function into string. That way you can send any commands to the remote side.

Do not use backticks. Use $(...).

for i in $(..) is an antipattern. Check your scripts with ShellCheck.

work() {
   uname -a
   uptime
   grep -E "warn|error|completed|issues|rollback" /var/adm/messages/*unix
}
for i in $(cat /tmp/srv_list); do
   ssh "$i" "$(declare -f work);work" >> /var/tmp/new.out
done

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