Re: [PATCHES] document plperl argument and return value representation
Andrew Dunstan wrote: Alvaro Herrera wrote: Andrew Dunstan wrote: The attached docs patch makes clearer how arguments and return values in pl/perl are escaped. This is to clarify the situation that Theo Schlossnagle recently reported on -bugs. I find the mix of arguments and results a bit confusing. Maybe you could put them in separate paragraphs. Is this better? Yup, looks very nice. This message also serves to test whether I removed the annoying Mail-Followup-To header. It was actually a _feature_ of mutt (followup_to, which fired when I replied to a list to which I'm subscribed), which I disabled. Sorry about that. ETOOMANYWHICH, sorry about that as well :-) -- Alvaro Herrerahttp://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
[PATCHES] document plperl argument and return value representation
The attached docs patch makes clearer how arguments and return values in
pl/perl are escaped. This is to clarify the situation that Theo
Schlossnagle recently reported on -bugs.
If there's no objection I will apply this.
cheers
andrew
? plperldoc.patch
Index: plperl.sgml
===
RCS file: /cvsroot/pgsql/doc/src/sgml/plperl.sgml,v
retrieving revision 2.65
diff -c -r2.65 plperl.sgml
*** plperl.sgml 3 May 2007 15:05:56 - 2.65
--- plperl.sgml 3 May 2007 22:19:05 -
***
*** 138,143
--- 138,169
/para
para
+Anything in a function argument or result that is not a reference is
+a string, which is in the standard productnamePostgreSQL/productname
+external text representation for the relevant data type. In the case of
+ordinary numeric or text types, Perl will just do the right thing and
+the programmer will normally not have to worry about it. However, in
+other cases the argument will need to be converted into a form that is
+more usable in Perl, and the return result will need to be converted to
+the form that productnamePostgreSQL/productname expects. For example,
+here is how to convert an argument of type bytea into unescaped binary
+data:
+
+ programlisting
+ my $arg = shift;
+ $arg =~ s!\\(\d{3})!chr(oct($1))!ge;
+ /programlisting
+
+and here is how to escape binary data for a return value of type bytea:
+
+ programlisting
+ $retval =~ s!([^ -~])!sprintf(\\%03o,ord($1))!ge;
+ return $retval;
+ /programlisting
+
+ /para
+
+ para
Perl can return productnamePostgreSQL/productname arrays as
references to Perl arrays. Here is an example:
---(end of broadcast)---
TIP 5: don't forget to increase your free space map settings
Re: [PATCHES] document plperl argument and return value representation
Andrew Dunstan wrote: The attached docs patch makes clearer how arguments and return values in pl/perl are escaped. This is to clarify the situation that Theo Schlossnagle recently reported on -bugs. I find the mix of arguments and results a bit confusing. Maybe you could put them in separate paragraphs. -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [PATCHES] document plperl argument and return value representation
Alvaro Herrera wrote:
Andrew Dunstan wrote:
The attached docs patch makes clearer how arguments and return values in
pl/perl are escaped. This is to clarify the situation that Theo
Schlossnagle recently reported on -bugs.
I find the mix of arguments and results a bit confusing. Maybe you
could put them in separate paragraphs.
Is this better?
I also took the opportunity to replace an unbalanced quote mark that was
screwing up the syntax highlighting.
cheers
andrew
Index: plperl.sgml
===
RCS file: /cvsroot/pgsql/doc/src/sgml/plperl.sgml,v
retrieving revision 2.65
diff -c -r2.65 plperl.sgml
*** plperl.sgml 3 May 2007 15:05:56 - 2.65
--- plperl.sgml 3 May 2007 23:44:04 -
***
*** 138,150
/para
para
Perl can return productnamePostgreSQL/productname arrays as
references to Perl arrays. Here is an example:
programlisting
CREATE OR REPLACE function returns_array()
RETURNS text[][] AS $$
! return [['ab','c,d'],['e\\f','g']];
$$ LANGUAGE plperl;
select returns_array();
--- 138,180
/para
para
+Anything in a function argument that is not a reference is
+a string, which is in the standard productnamePostgreSQL/productname
+external text representation for the relevant data type. In the case of
+ordinary numeric or text types, Perl will just do the right thing and
+the programmer will normally not have to worry about it. However, in
+other cases the argument will need to be converted into a form that is
+more usable in Perl. For example, here is how to convert an argument of
+type bytea into unescaped binary
+data:
+
+ programlisting
+ my $arg = shift;
+ $arg =~ s!\\(\d{3})!chr(oct($1))!ge;
+ /programlisting
+
+ /para
+
+ para
+Similarly, values passed back to productnamePostgreSQL/productname
+must be in the external text representation format. For example, here
+is how to escape binary data for a return value of type bytea:
+
+ programlisting
+ $retval =~ s!([^ -~])!sprintf(\\%03o,ord($1))!ge;
+ return $retval;
+ /programlisting
+
+ /para
+
+ para
Perl can return productnamePostgreSQL/productname arrays as
references to Perl arrays. Here is an example:
programlisting
CREATE OR REPLACE function returns_array()
RETURNS text[][] AS $$
! return [['aquot;b','c,d'],['e\\f','g']];
$$ LANGUAGE plperl;
select returns_array();
---(end of broadcast)---
TIP 4: Have you searched our list archives?
http://archives.postgresql.org
Re: [PATCHES] document plperl argument and return value representation
Andrew Dunstan [EMAIL PROTECTED] writes: Is this better? I suggest bytea - typebytea/, otherwise seems fine. regards, tom lane ---(end of broadcast)--- TIP 6: explain analyze is your friend
