<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style></style></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1>Hi Raphaël.<o:p></o:p><o:p> </o:p>> An empty file contains "\n", not "".<o:p></o:p>So what you are saying is, that Augeas doesn't understand the concept of empty files? It will always interpret them as beeing filled with an empty line (which translates into an empty tree node)?<o:p></o:p><o:p> </o:p>Even though, that doesn't explain my question what the difference between<o:p></o:p><o:p> </o:p>let lns = properties? . ( filler | domain )*<o:p></o:p><o:p> </o:p> and<o:p></o:p><o:p> </o:p>let lns = ( properties? . ( filler | domain )* )?<o:p></o:p><o:p> </o:p>is.<o:p></o:p><o:p> </o:p>Ciao,<o:p></o:p>Xavier.<o:p></o:p><o:p> </o:p><o:p> </o:p><o:p> </o:p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>From: Raphaël Pinson [mailto:raphael.pinson@camptocamp.com] Sent: Friday, February 12, 2016 11:00 AM To: Mol, Xavier (SCC) Cc: augeas-devel@redhat.com Subject: Re: [augeas-devel] Why does Augeas fail to handle empty files?<o:p></o:p></div></div><o:p> </o:p><div><o:p> </o:p><div><o:p> </o:p><div>On Fri, Feb 12, 2016 at 10:57 AM, Mol, Xavier (SCC) <<a href="mailto:xavier.mol@kit.edu" target="_blank">xavier.mol@kit.edu</a>> wrote:<o:p></o:p><div><div>Hi again.<o:p></o:p> <o:p></o:p>> let lns = ( properties? . ( filler | domain )* )?<o:p></o:p>One more note on this: After I have changed this line, augparse compains that a very complicated regular expression "matches the empty word", which actually is the point of the exercise.<o:p></o:p></div></div><div><o:p> </o:p></div><div>It shouldn't be. An empty file contains "\n", not "".<o:p></o:p></div><div><o:p> </o:p></div><div><o:p> </o:p></div><div>Raphaël<o:p></o:p></div><div><o:p> </o:p></div><div><o:p> </o:p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div> <o:p></o:p> <o:p></o:p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>From: <a href="mailto:augeas-devel-bounces@redhat.com" target="_blank">augeas-devel-bounces@redhat.com</a> [mailto:<a href="mailto:augeas-devel-bounces@redhat.com" target="_blank">augeas-devel-bounces@redhat.com</a>] On Behalf Of Mol, Xavier (SCC) Sent: Friday, February 12, 2016 9:13 AM To: <a href="mailto:augeas-devel@redhat.com" target="_blank">augeas-devel@redhat.com</a> Subject: [augeas-devel] Why does Augeas fail to handle empty files?<o:p></o:p></div></div><div><div> <o:p></o:p>Hello Augeas experts,<o:p></o:p> <o:p></o:p>this issue was mentioned in a previous mail thread on this list (see attached final mail) and I've run into it again: Augeas seems to be quite strict about empty files (as opposed to non-existing files).<o:p></o:p> <o:p></o:p>I have a lens defined like this 'let lns = properties? . ( filler | domain )*'. The actual meaning of the sub-lenses is not important right now, since per regular expression this should successfully match the void. It indeed does create new files, but it fails to update empty files and this is the error message I get:<o:p></o:p> <o:p></o:p>"""<o:p></o:p>[root ~]# >/etc/dcache/layouts/f01-151-109-e.conf<o:p></o:p>[root ~]# augtool<o:p></o:p>augtool> print /files/etc/dcache/layouts/f01-151-109-e.conf<o:p></o:p>/files/etc/dcache/layouts/f01-151-109-e.conf<o:p></o:p>augtool> set /files/etc/dcache/layouts/f01-151-109-e.conf/properties/dcache.java.memory.heap 2g<o:p></o:p>augtool> print /files/etc/dcache/layouts/f01-151-109-e.conf<o:p></o:p>/files/etc/dcache/layouts/f01-151-109-e.conf<o:p></o:p>/files/etc/dcache/layouts/f01-151-109-e.conf/properties<o:p></o:p>/files/etc/dcache/layouts/f01-151-109-e.conf/properties/dcache.java.memory.heap = "2g"<o:p></o:p>augtool> save<o:p></o:p>error: Failed to execute command<o:p></o:p>saving failed (run 'errors' for details)<o:p></o:p>augtool> errors<o:p></o:p>Error in /etc/dcache/layouts/f01-151-109-e.conf (put_failed)<o:p></o:p> Failed to match<o:p></o:p> { /properties/ }?<o:p></o:p>( { /#comment/ = /[^\001-\004\t\n\r ][^\001-\004\n]*[^\001-\004\t\n\r ]|[^\001-\004\t\n\r ]/ }<o:p></o:p> | { }<o:p></o:p> | { /domain/ = /[$.0-9A-Z_a-{}-]+/ })*<o:p></o:p> with tree<o:p></o:p> { } { "properties" }<o:p></o:p> Lens: /var/lib/puppet/lib/augeas/lenses/dcachelayout.aug:29.12-.46:<o:p></o:p>"""<o:p></o:p> <o:p></o:p>For some reason, there is an empty node before the properties node, which failes the put direction. For that the lens needs to be written like…<o:p></o:p> <o:p></o:p>let lns = ( properties? . ( filler | domain )* )?<o:p></o:p> <o:p></o:p>As far as regular expressions go, there is no effective change here, right? Yet for Augeas this clearly seems to make a difference. Can someone maybe explain this to me?<o:p></o:p> <o:p></o:p>Thank you for your time,<o:p></o:p>Xavier.<o:p></o:p> <o:p></o:p> <o:p></o:p>****<o:p></o:p>Karlsruher Institute of Technology (KIT)<o:p></o:p>Steinbuch Centre for Computing (SCC)<o:p></o:p> <o:p></o:p>B. Sc. Xavier Mol<o:p></o:p>GridKa Storage Administrator and Support Manager<o:p></o:p> <o:p></o:p>Hermann-von-Helmholtz-Platz 1<o:p></o:p>Geb. 449<o:p></o:p>76344 Eggenstein-Leopoldshafen<o:p></o:p>Phone: <a href="tel:%2B49%20721%20608%2023041" target="_blank">+49 721 608 23041</a><o:p></o:p>Email: <a href="mailto:xavier.mol@kit.edu" target="_blank">xavier.mol@kit.edu</a><o:p></o:p><a href="http://www.kit.edu/" target="_blank">www.kit.edu</a><o:p></o:p>KIT - University of the State of Baden-Württemberg and National Large-scale Research Center of the Helmholtz Association<o:p></o:p>"Since 2010, the KIT has been certified as a family-friendly university."<o:p></o:p>****<o:p></o:p> <o:p></o:p> <o:p></o:p></div></div></div></div></div> _______________________________________________ augeas-devel mailing list <a href="mailto:augeas-devel@redhat.com">augeas-devel@redhat.com</a> <a href="https://www.redhat.com/mailman/listinfo/augeas-devel" target="_blank">https://www.redhat.com/mailman/listinfo/augeas-devel</a><o:p></o:p></blockquote></div> <o:p></o:p><div><o:p> </o:p></div>-- <o:p></o:p><div><div><div><div>Raphaël Pinson<o:p></o:p><div>Infrastructure Developer & Training Leader<o:p></o:p></div><div>+33 458 482 013<o:p></o:p><div><o:p> </o:p></div><div>Camptocamp France Savoie Technolac BP 352 48, avenue du Lac du Bourget 73372 Le Bourget du Lac, Cedex <a href="http://www.camptocamp.com" target="_blank">www.camptocamp.com</a><o:p></o:p></div></div></div></div></div></div></div></div></div></div></body></html>