Add support for \x hex strings in psql variables.

Author: bmomjian

doc/src/sgml/ref/psql-ref.sgml

@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.137 2005/05/30 15:24:23 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.138 2005/06/02 01:23:48 momjian Exp $
 PostgreSQL documentation
 -->
 
@@ -589,8 +589,9 @@ testdb=&gt;
     single quote. To include a single quote into such an argument,
     precede it by a backslash. Anything contained in single quotes is
     furthermore subject to C-like substitutions for
-    <literal>\n</literal> (new line), <literal>\t</literal> (tab), and
-    <literal>\</literal><replaceable>digits</replaceable> (octal).
+    <literal>\n</literal> (new line), <literal>\t</literal> (tab),
+    <literal>\</literal><replaceable>digits</replaceable> (octal),
+    <literal>\x</literal><replaceable>digits</replaceable> (hexadecimal).
     </para>
 
     <para>

src/bin/psql/psqlscan.l

@@ -33,7 +33,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/psql/psqlscan.l,v 1.12 2005/05/30 16:48:47 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/bin/psql/psqlscan.l,v 1.13 2005/06/02 01:23:48 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -250,8 +250,9 @@ xnstart			[nN]{quote}
 xqstart			{quote}
 xqdouble		{quote}{quote}
 xqinside		[^\\']+
-xqescape		[\\][^0-7]
+xqescape		[\\][^0-7x]
 xqoctesc		[\\][0-7]{1,3}
+xqhexesc		[\\]x[0-9A-Fa-f]{1,2}
 
 /* $foo$ style quotes ("dollar quoting")
  * The quoted string starts with $foo$ where "foo" is an optional string
@@ -467,6 +468,9 @@ other			.
 <xq>{xqoctesc}  {
 					ECHO;
 				}
+<xq>{xqhexesc}  {
+					ECHO;
+				}
 <xq>{quotecontinue} {
 					ECHO;
 				}
@@ -855,6 +859,12 @@ other			.
 										  (char) strtol(yytext + 1, NULL, 8));
 				}
 
+{xqhexesc}		{
+					/* hex case */
+					appendPQExpBufferChar(output_buf,
+										  (char) strtol(yytext + 2, NULL, 16));
+				}
+
 "\\".			{ emit(yytext + 1, 1); }
 
 {other}|\n		{ ECHO; }