The following approach sobject <- charToRaw(serialize(object,NULL)) len <- length(sobject) writeBin(sobject, outcon)
would appear to work. As from 2.3.0 you will then be able to do unserialize(readBin(incon, "raw", n=len)) On Fri, 31 Mar 2006, Prof Brian Ripley wrote: > I think you should be using a raw type to hold such data in R. It is not > intentional that readChar handles embedded nuls (and in fact it might not in > an MBCS). > > As ?serialize says > > For 'serialize', 'NULL' unless 'connection=NULL', when the result > is stored in the first element of a character vector (but is not a > normal character string unless 'ascii = TRUE' and should not be > processed except by 'unserialize'). > > so you have been told this is not intended to work as you tried. > > serialize predates the raw type, or it would have made use of it. In these > days of MBCS character strings it is increasingly unsafe to use them to hold > anything other than valid character data. > > > On Thu, 30 Mar 2006, Jeffrey Horner wrote: > >> Is this possible? I've tried both writeChar() and writeBin() to no avail. >> >> My goal is to serialize(ascii=FALSE) an object to a connection but >> determine the size of the serialized object before hand: >> >> sobject <- serialize(object,NULL,ascii=FALSE) >> len <- nchar(sobject) >> # >> # run some code here to notify listener on other end of connection >> # how many bytes I'm getting ready to send >> # >> writeChar(sobject,con) >> >> The other option is to serialize twice: >> >> len <- nchar(serialize(object,NULL,ascii=FALSE)) >> # >> # run some code here to notify listener on other end of connection >> # how many bytes I'm getting ready to send >> # >> serialize(object,con,ascii=FALSE) >> >> Object stores, like memcache (http://danga.com/memcached/), need to know >> object sizes before storing. RDBMS's which support large objects (CLOBS >> or BLOBS) don't nececarilly need to know object sizes before-hand, but >> they do have max column size limits which must be honored. >> >> BTW, readchar() can read strings with embedded nulls; I figured >> writeChar() should be able to write them. >> >> > > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
