apenwarr-redo/t/350-deps/overwrite3.do

# we don't delete $3 here, we just truncate and overwrite it.  But redo
# can detect this by checking the current file position of our stdout when
# we exit, and making sure it equals either 0 or the file size.
#
# If it doesn't, then we accidentally wrote to *both* stdout and a separate
# file, and we should get warned about it.
echo hello world
echo goodbye world >$3
user-friendliness sanity checks: catch common mistakes regarding $1/$2/$3. .do files should never modify $1, and should write to either $3 or stdout, but not both. If they write to both, it's probably because they forgot to redirect stdout to stderr, a very easy mistake to make but a hard one to detect. Now redo detects it for you and prints an informative message. 2010-11-22 04:40:54 -08:00			`# we don't delete $3 here, we just truncate and overwrite it. But redo`
			`# can detect this by checking the current file position of our stdout when`
			`# we exit, and making sure it equals either 0 or the file size.`
			`#`
			`# If it doesn't, then we accidentally wrote to both stdout and a separate`
			`# file, and we should get warned about it.`
			`echo hello world`
			`echo goodbye world >$3`