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Comment by lordfoo | Hacker News Reader

Would you mind expanding on this with an example? I'm trying to improve performance of my bash logging

So this line only redirects all script output to a file as well as ensure that that output makes it onto your screen at the same time.

It is unstructured only in the way you allow any running command within your script to dump their output.

I run most commands inside my scripts with `> /dev/null 2>&1` and then rely on exit codes to wrap structured information to be echoed out with this function:

echo_l(){echo;echo '--------';echo "${1}";echo '--------';echo}

Or functions such as this to populate a log:

log_cat(){echo "${1}" >> ${__LOG} }

But the tee named pipe is the winner.

PS. The __DOC_LOCAL and __DIR variables start with these magic variables below. These variables are a life saver and allow easy directory and file manipulation, they kind of setup a top-level context:

# Set magic variables for current file & dir

__DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

__FILE="${__DIR}/$(basename "${BASH_SOURCE[0]}")"

__SCRIPT="$(basename ${__FILE})"

__BASE="$(basename ${__FILE} .sh)"

__ROOT="$(cd "$(dirname "${__DIR}")" && pwd)"

+1. My goal is to learn how to robustly do any logging whatsoever. Eager to learn new tricks.

Do you just want to log the scripts execution or do you want something more structured? If it's the former you can redirect the output from within the bash script with this (apologies for any condescension, I'm not familiar with your skill tree):

  if [ ! -t 1 ]; then
    exec > /my/log/file 2>&1
  fi

The if statements tests if your at an interactive prompt, if your not all output from the script get's redirected to /my/log/file. The above poster is instead redirecting into a subprocess " > (tee)" that will both print the output and log it.

It should be noted that often the bottleneck is the terminal itself, try running your scripts with a "> /dev/null" to suppress output and verify the slow part is actually the script.

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