Diff for "BashFAQ/044"

Anchor(faq44)

How do I create a progress bar?

The easiest way is to use dialog --gauge. Here is an example, which relies heavily on BASH features:

   # We want to process all of the *.zip files in the current directory.
   files=(*.zip)
   dialog --gauge "Working..." 20 75 < <(
      n=${#files[*]}; i=0
      for f in "${files[@]}"; do
         # process "$f" in some way (for testing, "sleep 1")
         echo $((100*(++i)/n))
      done)

Here's an explanation of what it's doing:

• An array named files is populated with all the files we want to process.

• dialog is invoked, and its input is redirected from a process substitution. (A pipe could also be used here; we'd simply have to reverse the dialog command and the loop.)

• The processing loop iterates over the array.

• Every time a file is processed, it increments a counter (i), and writes the percent complete to stdout.

For more examples of using dialog, see [:BashFAQ#faq40:FAQ #40].