Add time stamp to script log entries

Question

Currently I have my bash script using exec 22>&2 21>&1 1>$log 2>&1 to write stderr and stdout to a log file. I would like to add a time stamp for each entry, but I haven't found an easy way to do that. Ideally it would be a simple change to the current command with the time being written on the same line before the rest.

Here's a script that I'm using the command in:

#!/bin/bash

#This script takes the server to rysnc as an argument. You can also tell 
#the script to check the server_status.txt file.
#
#Example: /path/to/script/sync.sh grail true
#
#The arguments are order senstive. The server name must come before the status
#check value.

#Logfile
LOG=/var/log/sync.log

DIRECTORYS="auth/ keys/ log/mailwhen/ intranet/ www/calmaa/data/ www/admatch/data/ www/sfhsa/data/ www/hfa3_org www/padmatch/ www/serverdown/"

if [ "x$2" == "xfalse" ]; then
    return 0
elif [ "x$2" == "xtrue" ]; then
    if [ `cat /srv/www/wan*/server_status.txt` == "primary" ]; then
        exit 0
    fi
else
    echo "Please use \"true\" or \"false\" for the second value." 
    exit 1
fi

# Copy stdout and stderr, and then open the logfile
exec 22>&2 21>&1 1>$log 2>&1
# Here is how to restore stdout and stderr:
# exec 2>&22 1>&21

for DIRECTORY in $DIRECTORYS; do
    rsync -azu --delete --bwlimit=500 $1:/srv/$DIRECTORY  /srv/$DIRECTORY
done

score 3 · Accepted Answer · answered Sep 05 '13 at 02:36

3

Without seeing more of your script I can't tell you the best way for your particular needs. However this is a general way that can be adapted for your needs.

exec > >(while read -r line; do printf '%s %s\n' "$(date --rfc-3339=seconds)" "$line"; done)

Each line of text that is output will have the timestamp for the time that it occurred prepended. The output will look something like this:

2013-09-04 21:32:14-05:00 An event occurred and this is the message
2013-09-04 21:32:37-05:00 Some time passed, another event produced a message

answered Sep 05 '13 at 02:36

Dennis Williamson

62,149
16
116
151

This is more in line with what I want. – Ironlenny Sep 05 '13 at 19:53
That works great except it doesn't handle stderr. That is still logged with out a time stamp. – Ironlenny Sep 05 '13 at 23:29
@Ironlenny: You should be able to add `2>&1` after the closing parenthesis. Without seeing how you're using the other file descriptors, I can't really tell you how to use them. You can try a separate `exec` statement for them before the main one. By the way, to redirect the timestamped line to your log file, you should be able to add `>"$log"` between the `done` and the closing parenthesis. – Dennis Williamson Sep 06 '13 at 00:44

score 2 · Answer 2 · answered Sep 04 '13 at 19:01

2

edit stream with sed:

sed "s/^/$(date -u) /"

using pipe:

[root@giomacdesk ~]# cat test.txt 
asd1
asd2
[root@giomacdesk ~]# cat test.txt |sed "s/^/$(date -u) /"
ოთხ სექ  4 19:00:53 UTC 2013 asd1
ოთხ სექ  4 19:00:53 UTC 2013 asd2
[root@giomacdesk ~]#

answered Sep 04 '13 at 19:01

GioMac

4,544
4
27
41

1

That gives the same date/time on every line. – Dennis Williamson Sep 05 '13 at 02:20
GioMac, your solution requires a file that is already written. I want the time stamp appended to the string that is being written to the log file. – Ironlenny Sep 05 '13 at 23:16

Add time stamp to script log entries

2 Answers2