bash

I have been a bash hacker since I started with computers. That being said, I probably have some old habits on this page. This page primarily serves as short snippets of bash recipes I often want to re-use.

A lot of this bash is old and wrong, because I learned bash so long ago (1998?). Refer to http://mywiki.wooledge.org/BashGuide for proper rules.

• Simple Logging Redirect
• Human Size

Simple Logging Redirect

If you have a bash script you wish to add logging to a simple approach is to use exec and redirect the output to a file.

 exec > >(tee mylog) 2>&1

This is straight from the bash FAQ #106 so go there for details.

Human Size

This function converts a integer to the appropriate human size

  function human_size {
   local B=$1
   local S
   if [ "$B" -gt 1099511627776   ] ; then
     S="$(($B/1099511627776))tb"
   elif [ "$B" -gt 1073741824 ] ; then
     S="$(($B/1073741824))gb"
   elif [ "$B" -gt 1048576  ] ; then
     S="$(($B/1048576))mb"
   elif [ "$B" -gt 1024  ] ; then
     S="$(($B/1024))kb"
   else
     S="${B}b"
   fi
   echo $S
  }

NOTES

• This is sh compatible and not explicitly bash because it makes use of [ and should instead use [[