Thread: Re: [HACKERS] patches for items from TODO list
Here is an updated version of the COPY \x patch. It is the first patch
attached.
Also, I realized that if we support \x in COPY, we should also support
\x in strings to the backend. This is the second patch.
Third, I found out that psql has some unusual handling of escaped
numbers. Instead of using \ddd as octal, it has \ddd is decimal, \0ddd
is octal, and \0xddd is decimal. It is basically following the strtol()
rules for an escaped value. This seems confusing and contradicts how
the rest of our system works. I looked at 'bash' and found that it
supports the \000 and \x00 just like C, so I am confused why we have
the current behavior. This patch makes psql consistent with the rest of
our system for back slashes. It does break backward compatibility. It
wouldn't be a big deal to fix, except we document this in the psql
manual page, and that adds confusion.
FYI, here is the current psql behavior:
test=> \set x '\42'
test=> \echo :x
*
test=> \set x '\042'
test=> \echo :x
"
test=> \set x '\0x42'
test=> \echo :x
B
The new behavior is:
test=> \set x '\42'
test=> \echo :x
"
test=> \set x '\042'
test=> \echo :x
"
test=> \set x '\x42'
test=> \echo :x
B
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
Index: doc/src/sgml/ref/copy.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/copy.sgml,v
retrieving revision 1.65
diff -c -c -r1.65 copy.sgml
*** doc/src/sgml/ref/copy.sgml 7 May 2005 02:22:45 -0000 1.65
--- doc/src/sgml/ref/copy.sgml 28 May 2005 14:02:59 -0000
***************
*** 424,436 ****
<entry>Backslash followed by one to three octal digits specifies
the character with that numeric code</entry>
</row>
</tbody>
</tgroup>
</informaltable>
! Presently, <command>COPY TO</command> will never emit an octal-digits
! backslash sequence, but it does use the other sequences listed above
! for those control characters.
</para>
<para>
--- 424,441 ----
<entry>Backslash followed by one to three octal digits specifies
the character with that numeric code</entry>
</row>
+ <row>
+ <entry><literal>\x</><replaceable>digits</></entry>
+ <entry>Backslash <literal>x</> followed by one or two hex digits specifies
+ the character with that numeric code</entry>
+ </row>
</tbody>
</tgroup>
</informaltable>
! Presently, <command>COPY TO</command> will never emit an octal or
! hex-digits backslash sequence, but it does use the other sequences
! listed above for those control characters.
</para>
<para>
Index: src/backend/commands/copy.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/commands/copy.c,v
retrieving revision 1.244
diff -c -c -r1.244 copy.c
*** src/backend/commands/copy.c 7 May 2005 02:22:46 -0000 1.244
--- src/backend/commands/copy.c 28 May 2005 14:03:07 -0000
***************
*** 2274,2279 ****
--- 2274,2291 ----
return result;
}
+ /*
+ * Return decimal value for a hexadecimal digit
+ */
+ static
+ int GetDecimalFromHex(char hex)
+ {
+ if (isdigit(hex))
+ return hex - '0';
+ else
+ return tolower(hex) - 'a' + 10;
+ }
+
/*----------
* Read the value of a single attribute, performing de-escaping as needed.
*
***************
*** 2335,2340 ****
--- 2347,2353 ----
case '5':
case '6':
case '7':
+ /* handle \013 */
{
int val;
***************
*** 2360,2365 ****
--- 2373,2402 ----
c = val & 0377;
}
break;
+ case 'x':
+ /* Handle \x3F */
+ if (line_buf.cursor < line_buf.len)
+ {
+ char hexchar = line_buf.data[line_buf.cursor];
+
+ if (isxdigit(hexchar))
+ {
+ int val = GetDecimalFromHex(hexchar);
+
+ line_buf.cursor++;
+ if (line_buf.cursor < line_buf.len)
+ {
+ hexchar = line_buf.data[line_buf.cursor];
+ if (isxdigit(hexchar))
+ {
+ line_buf.cursor++;
+ val = (val << 4) + GetDecimalFromHex(hexchar);
+ }
+ }
+ c = val & 0xff;
+ }
+ }
+ break;
case 'b':
c = '\b';
break;
Index: doc/src/sgml/datatype.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v
retrieving revision 1.157
diff -c -c -r1.157 datatype.sgml
*** doc/src/sgml/datatype.sgml 1 May 2005 15:54:46 -0000 1.157
--- doc/src/sgml/datatype.sgml 28 May 2005 14:02:40 -0000
***************
*** 1118,1124 ****
<para>
When entering <type>bytea</type> values, octets of certain values
<emphasis>must</emphasis> be escaped (but all octet values
! <emphasis>may</emphasis> be escaped) when used as part of a string
literal in an <acronym>SQL</acronym> statement. In general, to
escape an octet, it is converted into the three-digit octal number
equivalent of its decimal octet value, and preceded by two
--- 1118,1124 ----
<para>
When entering <type>bytea</type> values, octets of certain values
<emphasis>must</emphasis> be escaped (but all octet values
! <emphasis>can</emphasis> be escaped) when used as part of a string
literal in an <acronym>SQL</acronym> statement. In general, to
escape an octet, it is converted into the three-digit octal number
equivalent of its decimal octet value, and preceded by two
Index: doc/src/sgml/libpq.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v
retrieving revision 1.180
diff -c -c -r1.180 libpq.sgml
*** doc/src/sgml/libpq.sgml 26 Feb 2005 18:39:04 -0000 1.180
--- doc/src/sgml/libpq.sgml 28 May 2005 14:02:46 -0000
***************
*** 2229,2235 ****
<para>
Certain byte values <emphasis>must</emphasis> be escaped (but all
! byte values <emphasis>may</emphasis> be escaped) when used as part
of a <type>bytea</type> literal in an <acronym>SQL</acronym>
statement. In general, to escape a byte, it is converted into the
three digit octal number equal to the octet value, and preceded by
--- 2229,2235 ----
<para>
Certain byte values <emphasis>must</emphasis> be escaped (but all
! byte values <emphasis>can</emphasis> be escaped) when used as part
of a <type>bytea</type> literal in an <acronym>SQL</acronym>
statement. In general, to escape a byte, it is converted into the
three digit octal number equal to the octet value, and preceded by
Index: doc/src/sgml/syntax.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v
retrieving revision 1.99
diff -c -c -r1.99 syntax.sgml
*** doc/src/sgml/syntax.sgml 23 Dec 2004 05:37:40 -0000 1.99
--- doc/src/sgml/syntax.sgml 28 May 2005 14:02:58 -0000
***************
*** 254,270 ****
<para>
Another <productname>PostgreSQL</productname> extension is that
! C-style backslash escapes are available:
! <literal>\b</literal> is a backspace, <literal>\f</literal> is a
! form feed, <literal>\n</literal> is a newline,
! <literal>\r</literal> is a carriage return, <literal>\t</literal>
! is a tab, and <literal>\<replaceable>xxx</replaceable></literal>,
! where <replaceable>xxx</replaceable> is an octal number, is a
! byte with the corresponding code. (It is your responsibility
! that the byte sequences you create are valid characters in the
! server character set encoding.) Any other character following a
! backslash is taken literally. Thus, to include a backslash in a
! string constant, write two backslashes.
</para>
<para>
--- 254,271 ----
<para>
Another <productname>PostgreSQL</productname> extension is that
! C-style backslash escapes are available: <literal>\b</literal> is a
! backspace, <literal>\f</literal> is a form feed,
! <literal>\n</literal> is a newline, <literal>\r</literal> is a
! carriage return, <literal>\t</literal> is a tab. Also supported is
! <literal>\<replaceable>digits</replaceable></literal>, where
! <replaceable>ddd</replaceable> represents an octal byte value, and
! <literal>\x<replaceable>hexdigits</replaceable></literal>, where
! <replaceable>hexdigits</replaceable> represents a hexadecimal byte value.
! (It is your responsibility that the byte sequences you create are
! valid characters in the server character set encoding.) Any other
! character following a backslash is taken literally. Thus, to
! include a backslash in a string constant, write two backslashes.
</para>
<para>
Index: src/backend/parser/scan.l
===================================================================
RCS file: /cvsroot/pgsql/src/backend/parser/scan.l,v
retrieving revision 1.122
diff -c -c -r1.122 scan.l
*** src/backend/parser/scan.l 26 May 2005 01:24:29 -0000 1.122
--- src/backend/parser/scan.l 28 May 2005 14:03:10 -0000
***************
*** 193,200 ****
xqstart {quote}
xqdouble {quote}{quote}
xqinside [^\\']+
! xqescape [\\][^0-7]
xqoctesc [\\][0-7]{1,3}
/* $foo$ style quotes ("dollar quoting")
* The quoted string starts with $foo$ where "foo" is an optional string
--- 193,201 ----
xqstart {quote}
xqdouble {quote}{quote}
xqinside [^\\']+
! 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
***************
*** 435,440 ****
--- 436,445 ----
unsigned char c = strtoul(yytext+1, NULL, 8);
addlitchar(c);
}
+ <xq>{xqhexesc} {
+ unsigned char c = strtoul(yytext+2, NULL, 16);
+ addlitchar(c);
+ }
<xq>{quotecontinue} {
/* ignore */
}
Index: doc/src/sgml/ref/psql-ref.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v
retrieving revision 1.135
diff -c -c -r1.135 psql-ref.sgml
*** doc/src/sgml/ref/psql-ref.sgml 28 Apr 2005 13:09:59 -0000 1.135
--- doc/src/sgml/ref/psql-ref.sgml 28 May 2005 16:23:01 -0000
***************
*** 590,599 ****
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),
! <literal>\</literal><replaceable>digits</replaceable>,
! <literal>\0</literal><replaceable>digits</replaceable>, and
! <literal>\0x</literal><replaceable>digits</replaceable> (the
! character with the given decimal, octal, or hexadecimal code).
</para>
<para>
--- 590,598 ----
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),
! <literal>\</literal><replaceable>digits</replaceable>, and
! <literal>\x</literal><replaceable>digits</replaceable> (the
! character with the given octal or hexadecimal code).
</para>
<para>
Index: src/bin/psql/psqlscan.l
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/psqlscan.l,v
retrieving revision 1.10
diff -c -c -r1.10 psqlscan.l
*** src/bin/psql/psqlscan.l 26 May 2005 01:24:29 -0000 1.10
--- src/bin/psql/psqlscan.l 28 May 2005 16:23:10 -0000
***************
*** 849,877 ****
"\\r" { appendPQExpBufferChar(output_buf, '\r'); }
"\\f" { appendPQExpBufferChar(output_buf, '\f'); }
! "\\"[1-9][0-9]* {
! /* decimal case */
! appendPQExpBufferChar(output_buf,
! (char) strtol(yytext + 1, NULL, 0));
! }
!
! "\\"0[0-7]* {
/* octal case */
appendPQExpBufferChar(output_buf,
! (char) strtol(yytext + 1, NULL, 0));
}
! "\\"0[xX][0-9A-Fa-f]+ {
/* hex case */
appendPQExpBufferChar(output_buf,
! (char) strtol(yytext + 1, NULL, 0));
! }
!
! "\\"0[xX] {
! /* failed hex case */
! yyless(2);
! appendPQExpBufferChar(output_buf,
! (char) strtol(yytext + 1, NULL, 0));
}
"\\". { emit(yytext + 1, 1); }
--- 849,864 ----
"\\r" { appendPQExpBufferChar(output_buf, '\r'); }
"\\f" { appendPQExpBufferChar(output_buf, '\f'); }
! "\\"[0-7]{1,3} {
/* octal case */
appendPQExpBufferChar(output_buf,
! (char) strtol(yytext + 1, NULL, 8));
}
! "\\"x[0-9A-Fa-f]{1,2} {
/* hex case */
appendPQExpBufferChar(output_buf,
! (char) strtol(yytext + 2, NULL, 16));
}
"\\". { emit(yytext + 1, 1); }
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Here is an updated version of the COPY \x patch. It is the first patch
> attached.
> Also, I realized that if we support \x in COPY, we should also support
> \x in strings to the backend. This is the second patch.
Do we really want to do any of these things? We've been getting beaten
up recently about the fact that we have non-SQL-spec string escapes
(ie, all the backslash stuff) so I'm a bit dubious about adding more,
especially when there's little if any demand for it.
I don't object too much to the COPY addition, since that's outside any
spec anyway, but I do think we ought to think twice about adding this
to SQL literal handling.
> Third, I found out that psql has some unusual handling of escaped
> numbers. Instead of using \ddd as octal, it has \ddd is decimal, \0ddd
> is octal, and \0xddd is decimal. It is basically following the strtol()
> rules for an escaped value. This seems confusing and contradicts how
> the rest of our system works.
I agree, that's just going to confuse people.
> ! xqescape [\\][^0-7x]
If you are going to insist on this, at least make it case-insensitive.
regards, tom lane
Tom Lane wrote: > Bruce Momjian <pgman@candle.pha.pa.us> writes: > >>Here is an updated version of the COPY \x patch. It is the first patch >>attached. >>Also, I realized that if we support \x in COPY, we should also support >>\x in strings to the backend. This is the second patch. > > > Do we really want to do any of these things? We've been getting beaten > up recently about the fact that we have non-SQL-spec string escapes > (ie, all the backslash stuff) so I'm a bit dubious about adding more, > especially when there's little if any demand for it. > > I don't object too much to the COPY addition, since that's outside any > spec anyway, but I do think we ought to think twice about adding this > to SQL literal handling. +1 from me on this for Tom -- please don't break spec compliance! Best Regards, Michael Paesold
Tom Lane wrote: > > Third, I found out that psql has some unusual handling of escaped > > numbers. Instead of using \ddd as octal, it has \ddd is decimal, \0ddd > > is octal, and \0xddd is decimal. It is basically following the strtol() > > rules for an escaped value. This seems confusing and contradicts how > > the rest of our system works. > > I agree, that's just going to confuse people. Fixed and applied, with no hex addition. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 Index: src/bin/psql/psqlscan.l =================================================================== RCS file: /cvsroot/pgsql/src/bin/psql/psqlscan.l,v retrieving revision 1.10 diff -c -c -r1.10 psqlscan.l *** src/bin/psql/psqlscan.l 26 May 2005 01:24:29 -0000 1.10 --- src/bin/psql/psqlscan.l 30 May 2005 14:35:43 -0000 *************** *** 849,877 **** "\\r" { appendPQExpBufferChar(output_buf, '\r'); } "\\f" { appendPQExpBufferChar(output_buf, '\f'); } ! "\\"[1-9][0-9]* { ! /* decimal case */ ! appendPQExpBufferChar(output_buf, ! (char) strtol(yytext + 1, NULL, 0)); ! } ! ! "\\"0[0-7]* { /* octal case */ appendPQExpBufferChar(output_buf, ! (char) strtol(yytext + 1, NULL, 0)); ! } ! ! "\\"0[xX][0-9A-Fa-f]+ { ! /* hex case */ ! appendPQExpBufferChar(output_buf, ! (char) strtol(yytext + 1, NULL, 0)); ! } ! ! "\\"0[xX] { ! /* failed hex case */ ! yyless(2); ! appendPQExpBufferChar(output_buf, ! (char) strtol(yytext + 1, NULL, 0)); } "\\". { emit(yytext + 1, 1); } --- 849,858 ---- "\\r" { appendPQExpBufferChar(output_buf, '\r'); } "\\f" { appendPQExpBufferChar(output_buf, '\f'); } ! "\\"[0-7]{1,3} { /* octal case */ appendPQExpBufferChar(output_buf, ! (char) strtol(yytext + 1, NULL, 8)); } "\\". { emit(yytext + 1, 1); }
Bruce Momjian wrote: > Here is an updated version of the COPY \x patch. It is the first patch > attached. > > Also, I realized that if we support \x in COPY, we should also support > \x in strings to the backend. This is the second patch. Here is a new version of the three \x hex support patches. I have added \x for psql variables, which is the last patch. I have IM'ed with Peter and he is now OK with the idea of supporting \x, with the underestanding that it doesn't take us any farther away from compatibility than we are now. I have already fixed the psql octal/decimal/hex behavior in another patch. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 Index: doc/src/sgml/ref/copy.sgml =================================================================== RCS file: /cvsroot/pgsql/doc/src/sgml/ref/copy.sgml,v retrieving revision 1.65 diff -c -c -r1.65 copy.sgml *** doc/src/sgml/ref/copy.sgml 7 May 2005 02:22:45 -0000 1.65 --- doc/src/sgml/ref/copy.sgml 28 May 2005 14:02:59 -0000 *************** *** 424,436 **** <entry>Backslash followed by one to three octal digits specifies the character with that numeric code</entry> </row> </tbody> </tgroup> </informaltable> ! Presently, <command>COPY TO</command> will never emit an octal-digits ! backslash sequence, but it does use the other sequences listed above ! for those control characters. </para> <para> --- 424,441 ---- <entry>Backslash followed by one to three octal digits specifies the character with that numeric code</entry> </row> + <row> + <entry><literal>\x</><replaceable>digits</></entry> + <entry>Backslash <literal>x</> followed by one or two hex digits specifies + the character with that numeric code</entry> + </row> </tbody> </tgroup> </informaltable> ! Presently, <command>COPY TO</command> will never emit an octal or ! hex-digits backslash sequence, but it does use the other sequences ! listed above for those control characters. </para> <para> Index: src/backend/commands/copy.c =================================================================== RCS file: /cvsroot/pgsql/src/backend/commands/copy.c,v retrieving revision 1.244 diff -c -c -r1.244 copy.c *** src/backend/commands/copy.c 7 May 2005 02:22:46 -0000 1.244 --- src/backend/commands/copy.c 28 May 2005 14:03:07 -0000 *************** *** 2274,2279 **** --- 2274,2291 ---- return result; } + /* + * Return decimal value for a hexadecimal digit + */ + static + int GetDecimalFromHex(char hex) + { + if (isdigit(hex)) + return hex - '0'; + else + return tolower(hex) - 'a' + 10; + } + /*---------- * Read the value of a single attribute, performing de-escaping as needed. * *************** *** 2335,2340 **** --- 2347,2353 ---- case '5': case '6': case '7': + /* handle \013 */ { int val; *************** *** 2360,2365 **** --- 2373,2402 ---- c = val & 0377; } break; + case 'x': + /* Handle \x3F */ + if (line_buf.cursor < line_buf.len) + { + char hexchar = line_buf.data[line_buf.cursor]; + + if (isxdigit(hexchar)) + { + int val = GetDecimalFromHex(hexchar); + + line_buf.cursor++; + if (line_buf.cursor < line_buf.len) + { + hexchar = line_buf.data[line_buf.cursor]; + if (isxdigit(hexchar)) + { + line_buf.cursor++; + val = (val << 4) + GetDecimalFromHex(hexchar); + } + } + c = val & 0xff; + } + } + break; case 'b': c = '\b'; break; Index: doc/src/sgml/syntax.sgml =================================================================== RCS file: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v retrieving revision 1.99 diff -c -c -r1.99 syntax.sgml *** doc/src/sgml/syntax.sgml 23 Dec 2004 05:37:40 -0000 1.99 --- doc/src/sgml/syntax.sgml 28 May 2005 14:02:58 -0000 *************** *** 254,270 **** <para> Another <productname>PostgreSQL</productname> extension is that ! C-style backslash escapes are available: ! <literal>\b</literal> is a backspace, <literal>\f</literal> is a ! form feed, <literal>\n</literal> is a newline, ! <literal>\r</literal> is a carriage return, <literal>\t</literal> ! is a tab, and <literal>\<replaceable>xxx</replaceable></literal>, ! where <replaceable>xxx</replaceable> is an octal number, is a ! byte with the corresponding code. (It is your responsibility ! that the byte sequences you create are valid characters in the ! server character set encoding.) Any other character following a ! backslash is taken literally. Thus, to include a backslash in a ! string constant, write two backslashes. </para> <para> --- 254,271 ---- <para> Another <productname>PostgreSQL</productname> extension is that ! C-style backslash escapes are available: <literal>\b</literal> is a ! backspace, <literal>\f</literal> is a form feed, ! <literal>\n</literal> is a newline, <literal>\r</literal> is a ! carriage return, <literal>\t</literal> is a tab. Also supported is ! <literal>\<replaceable>digits</replaceable></literal>, where ! <replaceable>ddd</replaceable> represents an octal byte value, and ! <literal>\x<replaceable>hexdigits</replaceable></literal>, where ! <replaceable>hexdigits</replaceable> represents a hexadecimal byte value. ! (It is your responsibility that the byte sequences you create are ! valid characters in the server character set encoding.) Any other ! character following a backslash is taken literally. Thus, to ! include a backslash in a string constant, write two backslashes. </para> <para> Index: src/backend/parser/scan.l =================================================================== RCS file: /cvsroot/pgsql/src/backend/parser/scan.l,v retrieving revision 1.122 diff -c -c -r1.122 scan.l *** src/backend/parser/scan.l 26 May 2005 01:24:29 -0000 1.122 --- src/backend/parser/scan.l 28 May 2005 14:03:10 -0000 *************** *** 193,200 **** xqstart {quote} xqdouble {quote}{quote} xqinside [^\\']+ ! xqescape [\\][^0-7] xqoctesc [\\][0-7]{1,3} /* $foo$ style quotes ("dollar quoting") * The quoted string starts with $foo$ where "foo" is an optional string --- 193,201 ---- xqstart {quote} xqdouble {quote}{quote} xqinside [^\\']+ ! 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 *************** *** 435,440 **** --- 436,445 ---- unsigned char c = strtoul(yytext+1, NULL, 8); addlitchar(c); } + <xq>{xqhexesc} { + unsigned char c = strtoul(yytext+2, NULL, 16); + addlitchar(c); + } <xq>{quotecontinue} { /* ignore */ } Index: doc/src/sgml/ref/psql-ref.sgml =================================================================== RCS file: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v retrieving revision 1.137 diff -c -c -r1.137 psql-ref.sgml *** doc/src/sgml/ref/psql-ref.sgml 30 May 2005 15:24:23 -0000 1.137 --- doc/src/sgml/ref/psql-ref.sgml 30 May 2005 19:07:20 -0000 *************** *** 589,596 **** 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). </para> <para> --- 589,597 ---- 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), ! <literal>\</literal><replaceable>digits</replaceable> (octal), ! <literal>\x</literal><replaceable>digits</replaceable> (hexadecimal). </para> <para> Index: src/bin/psql/psqlscan.l =================================================================== RCS file: /cvsroot/pgsql/src/bin/psql/psqlscan.l,v retrieving revision 1.12 diff -c -c -r1.12 psqlscan.l *** src/bin/psql/psqlscan.l 30 May 2005 16:48:47 -0000 1.12 --- src/bin/psql/psqlscan.l 30 May 2005 19:07:25 -0000 *************** *** 250,257 **** xqstart {quote} xqdouble {quote}{quote} xqinside [^\\']+ ! xqescape [\\][^0-7] xqoctesc [\\][0-7]{1,3} /* $foo$ style quotes ("dollar quoting") * The quoted string starts with $foo$ where "foo" is an optional string --- 250,258 ---- xqstart {quote} xqdouble {quote}{quote} xqinside [^\\']+ ! 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 *************** *** 467,472 **** --- 468,476 ---- <xq>{xqoctesc} { ECHO; } + <xq>{xqhexesc} { + ECHO; + } <xq>{quotecontinue} { ECHO; } *************** *** 855,860 **** --- 859,870 ---- (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; }
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Here is a new version of the three \x hex support patches. I have added
> \x for psql variables, which is the last patch.
> I have IM'ed with Peter and he is now OK with the idea of supporting \x,
> with the underestanding that it doesn't take us any farther away from
> compatibility than we are now.
Peter may be OK with it, but I object strongly to adding this to SQL
literals. This is exactly *not* the direction we want to be going in.
I don't really see the point for COPY and psql, either.
regards, tom lane