Question

How can I get the result of a hg update command in bash and use the results?

I’m interested in a true/false value or something similar. One of the errors I’m interested on is unknown revision.

Answer 1

First off I run it in a subshell and catch the output and exit code

result=$(hg update 2>&1)
exit_code=$?

then

case $exit_code in
0)
  success
  ;;
[1-5])
  failure x
  ;;
[6-9])
  failure y
  ;;
255)
  failure z
  ;;
*) # Default
  echo "it's a trap"
  ;;
esac

Or you can if you are interested in true/false status run

result=$(hg update 2>&1) && echo "Success"

or

result=$(hg update 2>&1) || echo "Failure"