Add timestamp to log

NotionCommotion · 06-16-2017, 08:21 AM

The following will append the output of /usr/local/monapp/monclient to /var/log/monclient.log. How can I add a timestamp before each entry?

Code:

SCRIPT=/usr/local/monapp/monclient
RUNAS=monclient
PIDFILE=/var/run/monclient.pid
LOGFILE=/var/log/monclient.log

start() {
  if [ -f "$PIDFILE" ] && kill -0 $(cat "$PIDFILE"); then
    echo "Service already running" >&2
    return 1
  fi
  echo "Starting $PROG…" >&2
  local CMD="$SCRIPT >&3 2>&1 & echo \$!"
  cd `dirname $SCRIPT`
  su -c "$CMD" $RUNAS  3>>"$LOGFILE" >"$PIDFILE"
  echo "Service started" >&2
}

business_kid · 06-16-2017, 08:57 AM

Perhaps invoke the 'date' command? No options required.

Turbocapitalist · 06-16-2017, 09:10 AM

Can you say a little more about the script /usr/local/monapp/monclient and its nature? It is what you would have to modify if you want the date-time to appear on every line of output that it produces.

Alternately, you might be able to wedge something in before your redirect.

Code:

. . . | awk '{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }' >> . . .

NotionCommotion · 06-16-2017, 09:35 AM

Quote:

Originally Posted by Turbocapitalist

Can you say a little more about the script /usr/local/monapp/monclient and its nature? It is what you would have to modify if you want the date-time to appear on every line of output that it produces.

Alternately, you might be able to wedge something in before your redirect.

Code:

. . . | awk '{ "date +\"%F %T\"" | getline datestamp; print datestamp "\t" $0; }' >> . . .

It is a client that monitors the local machine and send data to a remote server. It's logging functionality is limited to periodical writing to stdout debugging messages, and it does not include a timestamp with each message.

Looks like your script is searching for the date in each message sent to stdout?

Turbocapitalist · 06-16-2017, 09:42 AM

Quote:

Originally Posted by NotionCommotion

It is a client that monitors the local machine and send data to a remote server. It's logging functionality is limited to periodical writing to stdout debugging messages, and it does not include a timestamp with each message.

Looks like your script is searching for the date in each message sent to stdout?

Almost. It gets the date and time from the date utility and appends that to each line sent to stdout. However, see the updated version, I missed a proper close() function to force awk to get a new time for each line.

NotionCommotion · 06-16-2017, 10:18 AM

Thanks,

I've tried a couple of iterations, but this one errors with 25: local: +"%F: bad variable name, and the commented out one errors with awk: cannot open 3 (No such file or directory) bash: 3: Bad file descriptor.

Code:

#  local CMD="$SCRIPT >&3 2>&1 & echo \$!"
  local CMD="$SCRIPT | awk '{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }' >&3 2>&1 & echo \$!"
  cd `dirname $SCRIPT`
  su -c "$CMD" $RUNAS  3>>"$LOGFILE" >"$PIDFILE"
#  su -c "$CMD" $RUNAS  | awk '{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }' 3 >> "$LOGFILE" >"$PIDFILE"

Turbocapitalist · 06-16-2017, 10:33 AM

Quote:

Originally Posted by NotionCommotion

I've tried a couple of iterations, but this one errors

Yep. You have nested quotes which have to be escaped properly. When you have only two levels, you can alternate single ' and double " quotes to come to a solution. With three levels, it's significantly harder to look at:

Code:

sh -c "echo \"a $(date +\\" %F %T \\") b\" "

NotionCommotion · 06-16-2017, 10:46 AM

Yes, it is hard to look at!. This is what I ended up doing. Thanks!

Code:

#  local CMD="$SCRIPT >&3 2>&1 & echo \$!"
#  local CMD="$SCRIPT | awk '{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }' >&3 2>&1 & echo \$!"
  prnt='{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }'
  local CMD="$SCRIPT | awk '$prnt' >&3 2>&1 & echo \$!"
  cd `dirname $SCRIPT`
  su -c "$CMD" $RUNAS  3>>"$LOGFILE" >"$PIDFILE"
#  su -c "$CMD" $RUNAS  | awk '{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }' 3 >> "$LOGFILE" >"$PIDFILE"

NotionCommotion · 06-16-2017, 10:57 AM

Quote:

Originally Posted by NotionCommotion

Yes, it is hard to look at!. This is what I ended up doing. Thanks!

Hummm...

For some reason, some outputs from /usr/local/monapp/monclient are no longer being sent to the log. What might cause this?

Turbocapitalist · 06-16-2017, 11:01 AM

What is the result of the dirname action? Maybe you are not changing to the right directory?

You can try adding this line towards the beginning of your script during the debugging process.

Code:

set -ex

NotionCommotion · 06-16-2017, 11:20 AM

Quote:

Originally Posted by Turbocapitalist

What is the result of the dirname action? Maybe you are not changing to the right directory?

You can try adding this line towards the beginning of your script during the debugging process.

Code:

set -ex

Not sure about set -ex.
set=make variables available?
-e=exit?
-x=expand command?

The thing is I do get the entries I am expecting with my original script:

Code:

  local CMD="$SCRIPT >&3 2>&1 & echo \$!"
  cd `dirname $SCRIPT`
  su -c "$CMD" $RUNAS  3>>"$LOGFILE" >"$PIDFILE"

but not with this:

Code:

  prnt='{ "date +\"%F %T\"" | getline datestamp; close( "date +\"%F %T\"" ); print datestamp "\t" $0; }'
  local CMD="$SCRIPT | awk '$prnt' >&3 2>&1 & echo \$!"
  cd `dirname $SCRIPT`
  su -c "$CMD" $RUNAS  3>>"$LOGFILE" >"$PIDFILE"

Turbocapitalist · 06-16-2017, 01:36 PM

Quote:

Originally Posted by NotionCommotion

set=make variables available?
-e=exit?
-x=expand command?

The -e will stop the script if an error is encountered.

The -x will show you verbatim the command which will run, including all options. Whatever that shows should give you an idea of what the problem would be. In addition to the previous guess, I'd say trying to run the program in the background with the & is going to throw the results off.