How it works...

The -x flag outputs every line of script as it is executed. However, we may require only some portions of the source lines to be observed. Bash uses a set builtin to enable and disable debug printing within the script:

• set -x: This displays arguments and commands upon their execution
• set +x: This disables debugging
• set -v: This displays input when they are read
• set +v: This disables printing input