Template objects following methods:
set -x command to be more verbose.
The first letter can be either of '-' (which means the command
reads its standard input), 'f' (which means the commands reads
a given file on the command line) or '.' (which means the commands
reads no input, and hence must be first.)
Similarly, the second letter can be either of '-' (which means
the command writes to standard output), 'f' (which means the
command writes a file on the command line) or '.' (which means
the command does not write anything, and hence must be last.)
'r',
'w' may be given.