Home / ubuntu / Questions / 693002
Accepted
Edward Torvalds
Asked: 2015-11-03 08:11:16 +0800 CST

Log error of script to a file along with the date and time

  • 772

I can use 2> errorLogFile to log error of running script to a file right? my question is how to log the date and time of error along with error?

for example:

$ cat myScript
2> errorLogFile
..... # rest of the script

this is how the error file should look like:

$ cat errorLogFile
21 Nov 2015 2:00 PM some error happened
bash

1 Answers

  1. Best Answer

    You could redirect stderr to a process substitution which processes stderr and outputs the processed lines to the log.

    For example, this script will print 5 lines to stdout and 5 lines to stderr, redirecting stderr to a process susbstitution which processes stderr and outputs the processed lines to a file named "log" in the current working directory (mind that the syntax to redirect stderr is exec 2> [...], not 2> [...]):

    #!/bin/bash
exec 2> >(perl -pe '$x=`date "+%d %b %Y %H:%M %p"`;chomp($x);$_=$x." ".$_' >log)
for i in {1..5}; do
    sleep 1
    echo "STDOUT message #$i"
    echo "STDERR message #$i" >&2
done
exit 0

    The process substitution invokes Perl, which appends the current date and time in that format to each line and outputs them to a file named "log" in the current working directory.

    % bash script.sh
STDOUT message #1
STDOUT message #2
STDOUT message #3
STDOUT message #4
STDOUT message #5
% cat log
02 Nov 2015 20:15 PM STDERR message #1
02 Nov 2015 20:15 PM STDERR message #2
02 Nov 2015 20:15 PM STDERR message #3
02 Nov 2015 20:15 PM STDERR message #4
02 Nov 2015 20:15 PM STDERR message #5
    • 0