How to Log

ducasio · #1 (**permalink**) 08-31-04, 08:55

How can I write a script in bash so I can decide another log file instead of the default one? For treating the options I am using getopts.
e.g.

./myscript.sh logs to the default log file

and

./myscript.sh -l newlog logs to newlog file

Thank you in advance,
ducasio

Damian Ibbotson · #2 (**permalink**) 09-02-04, 05:46

You're not really giving enough information here but I'll have a go.

I'll assume that the 'default' log is standard out/err. If you actually have a 'default log' coded in your scripts, then you can modify the code below.

Code:

exec 3>&1
while getopts ":l:" opt; do
  case ${opt} in
    l) exec >${OPTARG} 2>&1;;
    *) echo "Invalid argument supplied" >&3; exit 1;;
  esac
done
shift $((OPTIND-1))

echo Stdout message >&1
echo Implicit stdout message
echo Stderr message >&2
echo Safe message to terminal >&3

e.g. yourScript -l aLogFile

ducasio · #3 (**permalink**) 09-03-04, 09:47

hi Damian,
in what I see it is very useful. Actually I must use different options with the script and every option should be valid in long and short form e.g.

./myshell.sh [[-? | --usage] | [-h | -history] [-l file | --log=file] ]

The redirection inside the script is something like this:

......
while getopts ":hl:" opt
do
done

echo 'hello' 2>&1 |tee -a $LOGFILE

And after, how can I menage the long options? How can I print ERR in the begining of every line of error(stderr) and LOG in the begining of every line of output(stdout)?

Thank you for you help
ducasio

Internet Services

Web Development

Digital Marketing

Consumer Tech