# exec
#
# Shell builtin command
# It can start a new process to replace the shell, without a new process
# creation. It can make redirections take effect in the current shell

# Redirect all STDOUT from within a script to the given file.
exec > foo.log

# Redirect all of both STDOUT & STDERR from within a script to the given file.
exec > foo.log 2>&1
# Or, if on bash(1), this syntax is also viable:
exec &> foo.log

# Copy output to a log file, allowing the outputs to still work as usual.
exec >  >(tee -ia foo.log)
exec 2> >(tee -ia foo.log >&2)