From 2325c99d07fa750c1098a3b2bc1bc80fb6bc846a Mon Sep 17 00:00:00 2001 From: "Richard W.M. Jones" Date: Fri, 12 Nov 2010 19:33:55 +0000 Subject: [PATCH] todo: Notes on parsing. --- TODO | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/TODO b/TODO index 2301c27..07e96f2 100644 --- a/TODO +++ b/TODO @@ -347,3 +347,31 @@ Eric Sandeen pointed out the blktrace tool which is a better way of capturing traces than using patched qemu (see contrib/visualize-alignment). We would still use the same visualization tools in conjunction with blktrace traces. + +guestfish parsing +----------------- + +At the moment guestfish uses an ad hoc parser which has many +shortcomings. We should change to using a lex/yacc-based scanner and +parser (there are better parsers out there, but yacc is sufficient and +very widely available). + +The scanner must deal with the case of parsing a whole command string, +eg. for a command that the user types in: + + > add-drive-opts "/tmp/foo" readonly:true + +and also with parsing single words from the command line: + + guestfish add-drive-opts /tmp/foo readonly:true + +Note the quotes are for scanning and don't indicate types. + +We should also allow variables and expressions as part of this new +parsing code, eg: + + set roots inspect-os + set product inspect-get-product-name %{roots[0]} + +% is better than $ because of shell escaping and confusion with shell +variables. -- 1.8.3.1