# Each variable or function that is created or modified is given the export attribute and marked for export to the environment of subsequent commands.
# Cause the status of terminated background jobs to be reported immediately, rather than before printing the next primary prompt.
# Disable filename expansion (globbing).
# Treat unset variables and parameters other than the special parameters ‘@’ or ‘*’ as an error when performing parameter expansion. An error message will be written to the standard error, and a non-interactive shell will exit.
# Print shell input lines as they are read.
# Print a trace of simple commands.