Thread

1. Re: non-standard escapes in string literals

   F Harvell <fharvell@fts.net> — 2002-04-25T17:30:34Z

   On Thu, 25 Apr 2002 10:41:56 EDT, Bruce Momjian wrote:
   > Andrew Pimlott wrote:
   > > I posted this some time ago to pgsql-bugs[1], to no response.  So
   > > I'll venture to try here.
   > > 
   > > Postgres breaks the standard for string literals by supporting
   > > C-like escape sequences.  This causes pain for people trying to
   > > write portable applications.  Is there any hope for an option to
   > > follow the standard strictly?
   > 
   > This is actually the first time this has come up (that I remember).  We
   > do support C escaping, but you are the first to mention that it can
   > cause problems for portable applications.
   > 
   > Anyone else want to comment?  I don't know how to address this.
   
   IMHO, I agree that I would like to see the ANSI standard implemented.
   
   While I really like PostgreSQL, it currently does not scale as large
   as other DBMS systems.  Due to this, we try to code as database
   agnostic as possible so that a port requires a minimum of effort.
   Currently there are only a few areas remaining that are at issue.
   (Intervals and implicit type conversion have/are being addressed).
   
   I believe that the reason that it hasn't come up as an issue, per se,
   is that it would only affect strings with a backslash in them.
   Backslash is not a commonly used character.  In addition, MySQL, also
   broken, uses backslashes in the same/similar way.  Lots of people
   using PostgreSQL are stepping up from MySQL.
   
   This also poses the biggest problem in terms of legacy compatibility.
   Perhaps the answer is to add a runtime config option (and default it
   to ANSI) and possibly deprecate the C escaping.
   
   Thanks,
   F Harvell
   
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2. Re: non-standard escapes in string literals

   Tom Lane <tgl@sss.pgh.pa.us> — 2002-04-25T19:07:44Z

   F Harvell <fharvell@fts.net> writes:
   > This also poses the biggest problem in terms of legacy compatibility.
   > Perhaps the answer is to add a runtime config option (and default it
   > to ANSI) and possibly deprecate the C escaping.
   
   While I wouldn't necessarily object to a runtime option, I do object
   to both the other parts of your proposal ;-).  Backslash escaping is
   not broken; we aren't going to remove it or deprecate it, and I would
   vote against making it non-default.
   
   			regards, tom lane
   
   

3. Re: non-standard escapes in string literals

   Bruce Momjian <pgman@candle.pha.pa.us> — 2002-04-25T20:22:10Z

   Tom Lane wrote:
   > F Harvell <fharvell@fts.net> writes:
   > > This also poses the biggest problem in terms of legacy compatibility.
   > > Perhaps the answer is to add a runtime config option (and default it
   > > to ANSI) and possibly deprecate the C escaping.
   > 
   > While I wouldn't necessarily object to a runtime option, I do object
   > to both the other parts of your proposal ;-).  Backslash escaping is
   > not broken; we aren't going to remove it or deprecate it, and I would
   > vote against making it non-default.
   
   Added to TODO:
   
    * Allow backslash handling in quoted strings to be disabled for portability
   
   -- 
     Bruce Momjian                        |  http://candle.pha.pa.us
     pgman@candle.pha.pa.us               |  (610) 853-3000
     +  If your life is a hard drive,     |  830 Blythe Avenue
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4. Re: non-standard escapes in string literals

   Florian Weimer <weimer@cert.uni-stuttgart.de> — 2002-05-03T21:58:07Z

   Bruce Momjian <pgman@candle.pha.pa.us> writes:
   
   > Added to TODO:
   >
   >  * Allow backslash handling in quoted strings to be disabled for portability
   
   BTW, what about embedded NUL characters in text strings? ;-)
   
   -- 
   Florian Weimer 	                  Weimer@CERT.Uni-Stuttgart.DE
   University of Stuttgart           http://CERT.Uni-Stuttgart.DE/people/fw/
   RUS-CERT                          +49-711-685-5973/fax +49-711-685-5898
   
   

5. Re: non-standard escapes in string literals

   Tom Lane <tgl@sss.pgh.pa.us> — 2002-05-03T22:29:04Z

   Florian Weimer <Weimer@CERT.Uni-Stuttgart.DE> writes:
   > BTW, what about embedded NUL characters in text strings? ;-)
   
   There's approximately zero chance of that happening in the foreseeable
   future.  Since null-terminated strings are the API for both the parser
   and all datatype I/O routines, there'd have to be a lot of code changed
   to support this.  To take just one example: strcoll() uses
   null-terminated strings, therefore we'd not be able to support
   locale-aware text comparisons unless we write our own replacement for
   the entire locale library.  (Which we might do someday, but it's not
   a trivial task.)
   
   The amount of pain involved seems to far outweigh the gain...
   
   			regards, tom lane