document stdin reading

Signed-off-by: Nico Schottelius <nico@brief.schottelius.org>
This commit is contained in:
Nico Schottelius 2012-06-04 16:14:28 +02:00
parent 3c1ab59b17
commit 56222d1f85

View file

@ -111,6 +111,33 @@ fi
--------------------------------------------------------------------------------
INPUT FROM STDIN
-----------------
Every type can access what has been written on stdin when it has been called.
The result is saved into the ***stdin*** file in the object directory.
Example use of a type: (e.g. in conf/type/__archlinux_hostname)
--------------------------------------------------------------------------------
__file /etc/rc.conf --source - << eof
...
HOSTNAME="$__target_host"
...
eof
--------------------------------------------------------------------------------
If you have not seen this syntax (<< eof) before, it may help you to read
about "here documents".
In the __file type, stdin is used as source for the file, if - is used for source:
--------------------------------------------------------------------------------
if [ -f "$__object/parameter/source" ]; then
source="$(cat "$__object/parameter/source")"
if [ "$source" = "-" ]; then
source="$__object/stdin"
fi
....
--------------------------------------------------------------------------------
WRITING THE MANIFEST
--------------------
In the manifest of a type you can use other types, so your type extends