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Extend format() to handle field width and left/right alignment.

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This change adds some more standard sprintf() functionality to format().

Pavel Stehule, reviewed by Dean Rasheed and Kyotaro Horiguchi
This commit is contained in:
Tom Lane 2013-03-14 22:56:56 -04:00
parent 1a1832eb08
commit 73e7025bd8
4 changed files with 657 additions and 98 deletions
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222
doc/src/sgml/func.sgml
View File

@ -1519,21 +1519,13 @@
<primary>format</primary> <primary>format</primary>
</indexterm> </indexterm>
<literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type> <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
[, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal> [, <parameter>formatarg</parameter> <type>"any"</type> [, ...] ])</literal>
</entry> </entry>
<entry><type>text</type></entry> <entry><type>text</type></entry>
<entry> <entry>
Format arguments according to a format string. Format arguments according to a format string.
This function is similar to the C function This function is similar to the C function <function>sprintf</>.
<function>sprintf</>, but only the following conversion specifications See <xref linkend="functions-string-format">.
are recognized: <literal>%s</literal> interpolates the corresponding
argument as a string; <literal>%I</literal> escapes its argument as
an SQL identifier; <literal>%L</literal> escapes its argument as an
SQL literal; <literal>%%</literal> outputs a literal <literal>%</>.
A conversion can reference an explicit parameter position by preceding
the conversion specifier with <literal><replaceable>n</>$</>, where
<replaceable>n</replaceable> is the argument position.
See also <xref linkend="plpgsql-quote-literal-example">.
</entry> </entry>
<entry><literal>format('Hello %s, %1$s', 'World')</literal></entry> <entry><literal>format('Hello %s, %1$s', 'World')</literal></entry>
<entry><literal>Hello World, World</literal></entry> <entry><literal>Hello World, World</literal></entry>
@ -2847,6 +2839,214 @@
</tgroup> </tgroup>
</table> </table>
<sect2 id="functions-string-format">
<title><function>format</function></title>
<indexterm>
<primary>format</primary>
</indexterm>
<para>
The function <function>format</> produces output formatted according to
a format string, in a style similar to the C function
<function>sprintf</>.
</para>
<para>
<synopsis>
<function>format</>(<parameter>formatstr</> <type>text</> [, <parameter>formatarg</> <type>"any"</> [, ...] ])
</synopsis>
<replaceable>formatstr</> is a format string that specifies how the
result should be formatted. Text in the format string is copied
directly to the result, except where <firstterm>format specifiers</> are
used. Format specifiers act as placeholders in the string, defining how
subsequent function arguments should be formatted and inserted into the
result. Each <replaceable>formatarg</> argument is converted to text
according to the usual output rules for its data type, and then formatted
and inserted into the result string according to the format specifier(s).
</para>
<para>
Format specifiers are introduced by a <literal>%</> character and have
the form
<synopsis>
%[<replaceable>position</>][<replaceable>flags</>][<replaceable>width</>]<replaceable>type</>
</synopsis>
where the component fields are:
<variablelist>
<varlistentry>
<term><replaceable>position</replaceable> (optional)</term>
<listitem>
<para>
A string of the form <literal><replaceable>n</>$</> where
<replaceable>n</> is the index of the argument to print.
Index 1 means the first argument after
<replaceable>formatstr</>. If the <replaceable>position</> is
omitted, the default is to use the next argument in sequence.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>flags</replaceable> (optional)</term>
<listitem>
<para>
Additional options controlling how the format specifier's output is
formatted. Currently the only supported flag is a minus sign
(<literal>-</>) which will cause the format specifier's output to be
left-justified. This has no effect unless the <replaceable>width</>
field is also specified.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>width</replaceable> (optional)</term>
<listitem>
<para>
Specifies the <emphasis>minimum</> number of characters to use to
display the format specifier's output. The output is padded on the
left or right (depending on the <literal>-</> flag) with spaces as
needed to fill the width. A too-small width does not cause
truncation of the output, but is simply ignored. The width may be
specified using any of the following: a positive integer; an
asterisk (<literal>*</>) to use the next function argument as the
width; or a string of the form <literal>*<replaceable>n</>$</> to
use the <replaceable>n</>th function argument as the width.
</para>
<para>
If the width comes from a function argument, that argument is
consumed before the argument that is used for the format specifier's
value. If the width argument is negative, the result is left
aligned (as if the <literal>-</> flag had been specified) within a
field of length <function>abs</>(<replaceable>width</replaceable>).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>type</replaceable> (required)</term>
<listitem>
<para>
The type of format conversion to use to produce the format
specifier's output. The following types are supported:
<itemizedlist>
<listitem>
<para>
<literal>s</literal> formats the argument value as a simple
string. A null value is treated as an empty string.
</para>
</listitem>
<listitem>
<para>
<literal>I</literal> treats the argument value as an SQL
identifier, double-quoting it if necessary.
It is an error for the value to be null.
</para>
</listitem>
<listitem>
<para>
<literal>L</literal> quotes the argument value as an SQL literal.
A null value is displayed as the string <literal>NULL</>, without
quotes.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
<para>
In addition to the format specifiers described above, the special sequence
<literal>%%</> may be used to output a literal <literal>%</> character.
</para>
<para>
Here are some examples of the basic format conversions:
<screen>
SELECT format('Hello %s', 'World');
<lineannotation>Result: </lineannotation><computeroutput>Hello World</computeroutput>
SELECT format('Testing %s, %s, %s, %%', 'one', 'two', 'three');
<lineannotation>Result: </><computeroutput>Testing one, two, three, %</>
SELECT format('INSERT INTO %I VALUES(%L)', 'Foo bar', E'O\'Reilly');
<lineannotation>Result: </lineannotation><computeroutput>INSERT INTO "Foo bar" VALUES('O''Reilly')</computeroutput>
SELECT format('INSERT INTO %I VALUES(%L)', 'locations', E'C:\\Program Files');
<lineannotation>Result: </lineannotation><computeroutput>INSERT INTO locations VALUES(E'C:\\Program Files')</computeroutput>
</screen>
</para>
<para>
Here are examples using <replaceable>width</replaceable> fields
and the <literal>-</> flag:
<screen>
SELECT format('|%10s|', 'foo');
<lineannotation>Result: </><computeroutput>| foo|</>
SELECT format('|%-10s|', 'foo');
<lineannotation>Result: </><computeroutput>|foo |</>
SELECT format('|%*s|', 10, 'foo');
<lineannotation>Result: </><computeroutput>| foo|</>
SELECT format('|%*s|', -10, 'foo');
<lineannotation>Result: </><computeroutput>|foo |</>
SELECT format('|%-*s|', 10, 'foo');
<lineannotation>Result: </><computeroutput>|foo |</>
SELECT format('|%-*s|', -10, 'foo');
<lineannotation>Result: </><computeroutput>|foo |</>
</screen>
</para>
<para>
These examples show use of <replaceable>position</> fields:
<screen>
SELECT format('Testing %3$s, %2$s, %1$s', 'one', 'two', 'three');
<lineannotation>Result: </><computeroutput>Testing three, two, one</>
SELECT format('|%*2$s|', 'foo', 10, 'bar');
<lineannotation>Result: </><computeroutput>| bar|</>
SELECT format('|%1$*2$s|', 'foo', 10, 'bar');
<lineannotation>Result: </><computeroutput>| foo|</>
</screen>
</para>
<para>
Unlike the standard C function <function>sprintf</>,
<productname>PostgreSQL</>'s <function>format</> function allows format
specifiers with and without <replaceable>position</> fields to be mixed
in the same format string. A format specifier without a
<replaceable>position</> field always uses the next argument after the
last argument consumed.
In addition, the <function>format</> function does not require all
function arguments to be used in the format string.
For example:
<screen>
SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three');
<lineannotation>Result: </><computeroutput>Testing three, two, three</>
</screen>
</para>
<para>
The <literal>%I</> and <literal>%L</> format specifiers are particularly
useful for safely constructing dynamic SQL statements. See
<xref linkend="plpgsql-quote-literal-example">.
</para>
</sect2>
</sect1> </sect1>

397
src/backend/utils/adt/varlena.c
View File

@ -56,32 +56,41 @@ typedef struct
#define PG_GETARG_UNKNOWN_P_COPY(n) DatumGetUnknownPCopy(PG_GETARG_DATUM(n)) #define PG_GETARG_UNKNOWN_P_COPY(n) DatumGetUnknownPCopy(PG_GETARG_DATUM(n))
#define PG_RETURN_UNKNOWN_P(x) PG_RETURN_POINTER(x) #define PG_RETURN_UNKNOWN_P(x) PG_RETURN_POINTER(x)
static int text_cmp(text *arg1, text *arg2, Oid collid);
static int32 text_length(Datum str); static int32 text_length(Datum str);
static int text_position(text *t1, text *t2);
static void text_position_setup(text *t1, text *t2, TextPositionState *state);
static int text_position_next(int start_pos, TextPositionState *state);
static void text_position_cleanup(TextPositionState *state);
static text *text_catenate(text *t1, text *t2); static text *text_catenate(text *t1, text *t2);
static text *text_substring(Datum str, static text *text_substring(Datum str,
int32 start, int32 start,
int32 length, int32 length,
bool length_not_specified); bool length_not_specified);
static text *text_overlay(text *t1, text *t2, int sp, int sl); static text *text_overlay(text *t1, text *t2, int sp, int sl);
static void appendStringInfoText(StringInfo str, const text *t); static int text_position(text *t1, text *t2);
static void text_position_setup(text *t1, text *t2, TextPositionState *state);
static int text_position_next(int start_pos, TextPositionState *state);
static void text_position_cleanup(TextPositionState *state);
static int text_cmp(text *arg1, text *arg2, Oid collid);
static bytea *bytea_catenate(bytea *t1, bytea *t2); static bytea *bytea_catenate(bytea *t1, bytea *t2);
static bytea *bytea_substring(Datum str, static bytea *bytea_substring(Datum str,
int S, int S,
int L, int L,
bool length_not_specified); bool length_not_specified);
static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl); static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
static StringInfo makeStringAggState(FunctionCallInfo fcinfo); static void appendStringInfoText(StringInfo str, const text *t);
static void text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull);
static Datum text_to_array_internal(PG_FUNCTION_ARGS); static Datum text_to_array_internal(PG_FUNCTION_ARGS);
static text *array_to_text_internal(FunctionCallInfo fcinfo, ArrayType *v, static text *array_to_text_internal(FunctionCallInfo fcinfo, ArrayType *v,
const char *fldsep, const char *null_string); const char *fldsep, const char *null_string);
static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
static bool text_format_parse_digits(const char **ptr, const char *end_ptr,
int *value);
static const char *text_format_parse_format(const char *start_ptr,
const char *end_ptr,
int *argpos, int *widthpos,
int *flags, int *width);
static void text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull,
int flags, int width);
static void text_format_append_string(StringInfo buf, const char *str,
int flags, int width);
/***************************************************************************** /*****************************************************************************
@ -3996,8 +4005,22 @@ text_reverse(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result); PG_RETURN_TEXT_P(result);
} }
/* /*
* Returns a formated string * Support macros for text_format()
*/
#define TEXT_FORMAT_FLAG_MINUS 0x0001 /* is minus flag present? */
#define ADVANCE_PARSE_POINTER(ptr,end_ptr) \
do { \
if (++(ptr) >= (end_ptr)) \
ereport(ERROR, \
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
errmsg("unterminated format specifier"))); \
} while (0)
/*
* Returns a formatted string
*/ */
Datum Datum
text_format(PG_FUNCTION_ARGS) text_format(PG_FUNCTION_ARGS)
@ -4008,16 +4031,18 @@ text_format(PG_FUNCTION_ARGS)
const char *start_ptr; const char *start_ptr;
const char *end_ptr; const char *end_ptr;
text *result; text *result;
int arg = 0; int arg;
bool funcvariadic; bool funcvariadic;
int nargs; int nargs;
Datum *elements = NULL; Datum *elements = NULL;
bool *nulls = NULL; bool *nulls = NULL;
Oid element_type = InvalidOid; Oid element_type = InvalidOid;
Oid prev_type = InvalidOid; Oid prev_type = InvalidOid;
Oid prev_width_type = InvalidOid;
FmgrInfo typoutputfinfo; FmgrInfo typoutputfinfo;
FmgrInfo typoutputinfo_width;
/* When format string is null, returns null */ /* When format string is null, immediately return null */
if (PG_ARGISNULL(0)) if (PG_ARGISNULL(0))
PG_RETURN_NULL(); PG_RETURN_NULL();
@ -4081,10 +4106,15 @@ text_format(PG_FUNCTION_ARGS)
start_ptr = VARDATA_ANY(fmt); start_ptr = VARDATA_ANY(fmt);
end_ptr = start_ptr + VARSIZE_ANY_EXHDR(fmt); end_ptr = start_ptr + VARSIZE_ANY_EXHDR(fmt);
initStringInfo(&str); initStringInfo(&str);
arg = 1; /* next argument position to print */
/* Scan format string, looking for conversion specifiers. */ /* Scan format string, looking for conversion specifiers. */
for (cp = start_ptr; cp < end_ptr; cp++) for (cp = start_ptr; cp < end_ptr; cp++)
{ {
int argpos;
int widthpos;
int flags;
int width;
Datum value; Datum value;
bool isNull; bool isNull;
Oid typid; Oid typid;
@ -4099,11 +4129,7 @@ text_format(PG_FUNCTION_ARGS)
continue; continue;
} }
/* Did we run off the end of the string? */ ADVANCE_PARSE_POINTER(cp, end_ptr);
if (++cp >= end_ptr)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unterminated conversion specifier")));
/* Easy case: %% outputs a single % */ /* Easy case: %% outputs a single % */
if (*cp == '%') if (*cp == '%')
@ -4112,69 +4138,89 @@ text_format(PG_FUNCTION_ARGS)
continue; continue;
} }
/* Parse the optional portions of the format specifier */
cp = text_format_parse_format(cp, end_ptr,
&argpos, &widthpos,
&flags, &width);
/* /*
* If the user hasn't specified an argument position, we just advance * Next we should see the main conversion specifier. Whether or not
* to the next one. If they have, we must parse it. * an argument position was present, it's known that at least one
* character remains in the string at this point. Experience suggests
* that it's worth checking that that character is one of the expected
* ones before we try to fetch arguments, so as to produce the least
* confusing response to a mis-formatted specifier.
*/ */
if (*cp < '0' || *cp > '9') if (strchr("sIL", *cp) == NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized conversion type specifier \"%c\"",
*cp)));
/* If indirect width was specified, get its value */
if (widthpos >= 0)
{ {
++arg; /* Collect the specified or next argument position */
if (arg <= 0) /* overflow? */ if (widthpos > 0)
{ arg = widthpos;
/* if (arg >= nargs)
* Should not happen, as you can't pass billions of arguments
* to a function, but better safe than sorry.
*/
ereport(ERROR, ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE), (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument number is out of range"))); errmsg("too few arguments for format")));
}
}
else
{
bool unterminated = false;
/* Parse digit string. */ /* Get the value and type of the selected argument */
arg = 0; if (!funcvariadic)
do
{ {
int newarg = arg * 10 + (*cp - '0'); value = PG_GETARG_DATUM(arg);
isNull = PG_ARGISNULL(arg);
if (newarg / 10 != arg) /* overflow? */ typid = get_fn_expr_argtype(fcinfo->flinfo, arg);
ereport(ERROR, }
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("argument number is out of range")));
arg = newarg;
++cp;
} while (cp < end_ptr && *cp >= '0' && *cp <= '9');
/*
* If we ran off the end, or if there's not a $ next, or if the $
* is the last character, the conversion specifier is improperly
* terminated.
*/
if (cp == end_ptr || *cp != '$')
unterminated = true;
else else
{ {
++cp; value = elements[arg - 1];
if (cp == end_ptr) isNull = nulls[arg - 1];
unterminated = true; typid = element_type;
} }
if (unterminated) if (!OidIsValid(typid))
ereport(ERROR, elog(ERROR, "could not determine data type of format() input");
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unterminated conversion specifier")));
/* There's no argument 0. */ arg++;
if (arg == 0)
ereport(ERROR, /* We can treat NULL width the same as zero */
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), if (isNull)
errmsg("conversion specifies argument 0, but arguments are numbered from 1"))); width = 0;
else if (typid == INT4OID)
width = DatumGetInt32(value);
else if (typid == INT2OID)
width = DatumGetInt16(value);
else
{
/* For less-usual datatypes, convert to text then to int */
char *str;
if (typid != prev_width_type)
{
Oid typoutputfunc;
bool typIsVarlena;
getTypeOutputInfo(typid, &typoutputfunc, &typIsVarlena);
fmgr_info(typoutputfunc, &typoutputinfo_width);
prev_width_type = typid;
}
str = OutputFunctionCall(&typoutputinfo_width, value);
/* pg_atoi will complain about bad data or overflow */
width = pg_atoi(str, sizeof(int), '\0');
pfree(str);
}
} }
/* Not enough arguments? Deduct 1 to avoid counting format string. */ /* Collect the specified or next argument position */
if (arg > nargs - 1) if (argpos > 0)
arg = argpos;
if (arg >= nargs)
ereport(ERROR, ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("too few arguments for format"))); errmsg("too few arguments for format")));
@ -4195,6 +4241,8 @@ text_format(PG_FUNCTION_ARGS)
if (!OidIsValid(typid)) if (!OidIsValid(typid))
elog(ERROR, "could not determine data type of format() input"); elog(ERROR, "could not determine data type of format() input");
arg++;
/* /*
* Get the appropriate typOutput function, reusing previous one if * Get the appropriate typOutput function, reusing previous one if
* same type as previous argument. That's particularly useful in the * same type as previous argument. That's particularly useful in the
@ -4211,9 +4259,7 @@ text_format(PG_FUNCTION_ARGS)
} }
/* /*
* At this point, we should see the main conversion specifier. Whether * And now we can format the value.
* or not an argument position was present, it's known that at least
* one character remains in the string at this point.
*/ */
switch (*cp) switch (*cp)
{ {
@ -4221,13 +4267,16 @@ text_format(PG_FUNCTION_ARGS)
case 'I': case 'I':
case 'L': case 'L':
text_format_string_conversion(&str, *cp, &typoutputfinfo, text_format_string_conversion(&str, *cp, &typoutputfinfo,
value, isNull); value, isNull,
flags, width);
break; break;
default: default:
/* should not get here, because of previous check */
ereport(ERROR, ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized conversion specifier \"%c\"", errmsg("unrecognized conversion type specifier \"%c\"",
*cp))); *cp)));
break;
} }
} }
@ -4244,19 +4293,157 @@ text_format(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result); PG_RETURN_TEXT_P(result);
} }
/* Format a %s, %I, or %L conversion. */ /*
* Parse contiguous digits as a decimal number.
*
* Returns true if some digits could be parsed.
* The value is returned into *value, and *ptr is advanced to the next
* character to be parsed.
*
* Note parsing invariant: at least one character is known available before
* string end (end_ptr) at entry, and this is still true at exit.
*/
static bool
text_format_parse_digits(const char **ptr, const char *end_ptr, int *value)
{
bool found = false;
const char *cp = *ptr;
int val = 0;
while (*cp >= '0' && *cp <= '9')
{
int newval = val * 10 + (*cp - '0');
if (newval / 10 != val) /* overflow? */
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("number is out of range")));
val = newval;
ADVANCE_PARSE_POINTER(cp, end_ptr);
found = true;
}
*ptr = cp;
*value = val;
return found;
}
/*
* Parse a format specifier (generally following the SUS printf spec).
*
* We have already advanced over the initial '%', and we are looking for
* [argpos][flags][width]type (but the type character is not consumed here).
*
* Inputs are start_ptr (the position after '%') and end_ptr (string end + 1).
* Output parameters:
* argpos: argument position for value to be printed. -1 means unspecified.
* widthpos: argument position for width. Zero means the argument position
* was unspecified (ie, take the next arg) and -1 means no width
* argument (width was omitted or specified as a constant).
* flags: bitmask of flags.
* width: directly-specified width value. Zero means the width was omitted
* (note it's not necessary to distinguish this case from an explicit
* zero width value).
*
* The function result is the next character position to be parsed, ie, the
* location where the type character is/should be.
*
* Note parsing invariant: at least one character is known available before
* string end (end_ptr) at entry, and this is still true at exit.
*/
static const char *
text_format_parse_format(const char *start_ptr, const char *end_ptr,
int *argpos, int *widthpos,
int *flags, int *width)
{
const char *cp = start_ptr;
int n;
/* set defaults for output parameters */
*argpos = -1;
*widthpos = -1;
*flags = 0;
*width = 0;
/* try to identify first number */
if (text_format_parse_digits(&cp, end_ptr, &n))
{
if (*cp != '$')
{
/* Must be just a width and a type, so we're done */
*width = n;
return cp;
}
/* The number was argument position */
*argpos = n;
/* Explicit 0 for argument index is immediately refused */
if (n == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("format specifies argument 0, but arguments are numbered from 1")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
/* Handle flags (only minus is supported now) */
while (*cp == '-')
{
*flags |= TEXT_FORMAT_FLAG_MINUS;
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
if (*cp == '*')
{
/* Handle indirect width */
ADVANCE_PARSE_POINTER(cp, end_ptr);
if (text_format_parse_digits(&cp, end_ptr, &n))
{
/* number in this position must be closed by $ */
if (*cp != '$')
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("width argument position must be ended by \"$\"")));
/* The number was width argument position */
*widthpos = n;
/* Explicit 0 for argument index is immediately refused */
if (n == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("format specifies argument 0, but arguments are numbered from 1")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
else
*widthpos = 0; /* width's argument position is unspecified */
}
else
{
/* Check for direct width specification */
if (text_format_parse_digits(&cp, end_ptr, &n))
*width = n;
}
/* cp should now be pointing at type character */
return cp;
}
/*
* Format a %s, %I, or %L conversion
*/
static void static void
text_format_string_conversion(StringInfo buf, char conversion, text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo, FmgrInfo *typOutputInfo,
Datum value, bool isNull) Datum value, bool isNull,
int flags, int width)
{ {
char *str; char *str;
/* Handle NULL arguments before trying to stringify the value. */ /* Handle NULL arguments before trying to stringify the value. */
if (isNull) if (isNull)
{ {
if (conversion == 'L') if (conversion == 's')
appendStringInfoString(buf, "NULL"); text_format_append_string(buf, "", flags, width);
else if (conversion == 'L')
text_format_append_string(buf, "NULL", flags, width);
else if (conversion == 'I') else if (conversion == 'I')
ereport(ERROR, ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
@ -4271,23 +4458,71 @@ text_format_string_conversion(StringInfo buf, char conversion,
if (conversion == 'I') if (conversion == 'I')
{ {
/* quote_identifier may or may not allocate a new string. */ /* quote_identifier may or may not allocate a new string. */
appendStringInfoString(buf, quote_identifier(str)); text_format_append_string(buf, quote_identifier(str), flags, width);
} }
else if (conversion == 'L') else if (conversion == 'L')
{ {
char *qstr = quote_literal_cstr(str); char *qstr = quote_literal_cstr(str);
appendStringInfoString(buf, qstr); text_format_append_string(buf, qstr, flags, width);
/* quote_literal_cstr() always allocates a new string */ /* quote_literal_cstr() always allocates a new string */
pfree(qstr); pfree(qstr);
} }
else else
appendStringInfoString(buf, str); text_format_append_string(buf, str, flags, width);
/* Cleanup. */ /* Cleanup. */
pfree(str); pfree(str);
} }
/*
* Append str to buf, padding as directed by flags/width
*/
static void
text_format_append_string(StringInfo buf, const char *str,
int flags, int width)
{
bool align_to_left = false;
int len;
/* fast path for typical easy case */
if (width == 0)
{
appendStringInfoString(buf, str);
return;
}
if (width < 0)
{
/* Negative width: implicit '-' flag, then take absolute value */
align_to_left = true;
/* -INT_MIN is undefined */
if (width <= INT_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("number is out of range")));
width = -width;
}
else if (flags & TEXT_FORMAT_FLAG_MINUS)
align_to_left = true;
len = pg_mbstrlen(str);
if (align_to_left)
{
/* left justify */
appendStringInfoString(buf, str);
if (len < width)
appendStringInfoSpaces(buf, width - len);
}
else
{
/* right justify */
if (len < width)
appendStringInfoSpaces(buf, width - len);
appendStringInfoString(buf, str);
}
}
/* /*
* text_format_nv - nonvariadic wrapper for text_format function. * text_format_nv - nonvariadic wrapper for text_format function.
* *

115
src/test/regress/expected/text.out
View File

@ -209,7 +209,7 @@ ERROR: too few arguments for format
select format('Hello %s'); select format('Hello %s');
ERROR: too few arguments for format ERROR: too few arguments for format
select format('Hello %x', 20); select format('Hello %x', 20);
ERROR: unrecognized conversion specifier "x" ERROR: unrecognized conversion type specifier "x"
-- check literal and sql identifiers -- check literal and sql identifiers
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, 'Hello'); select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, 'Hello');
format format
@ -256,12 +256,14 @@ select format('%1$s %4$s', 1, 2, 3);
ERROR: too few arguments for format ERROR: too few arguments for format
select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
ERROR: too few arguments for format ERROR: too few arguments for format
select format('%1s', 1); select format('%0$s', 'Hello');
ERROR: unterminated conversion specifier ERROR: format specifies argument 0, but arguments are numbered from 1
select format('%*0$s', 'Hello');
ERROR: format specifies argument 0, but arguments are numbered from 1
select format('%1$', 1); select format('%1$', 1);
ERROR: unterminated conversion specifier ERROR: unterminated format specifier
select format('%1$1', 1); select format('%1$1', 1);
ERROR: unrecognized conversion specifier "1" ERROR: unterminated format specifier
-- check mix of positional and ordered placeholders -- check mix of positional and ordered placeholders
select format('Hello %s %1$s %s', 'World', 'Hello again'); select format('Hello %s %1$s %s', 'World', 'Hello again');
format format
@ -328,3 +330,106 @@ from generate_series(1,200) g(i);
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200
(1 row) (1 row)
-- check field widths and left, right alignment
select format('>>%10s<<', 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%10s<<', NULL);
format
----------------
>> <<
(1 row)
select format('>>%10s<<', '');
format
----------------
>> <<
(1 row)
select format('>>%-10s<<', '');
format
----------------
>> <<
(1 row)
select format('>>%-10s<<', 'Hello');
format
----------------
>>Hello <<
(1 row)
select format('>>%-10s<<', NULL);
format
----------------
>> <<
(1 row)
select format('>>%1$10s<<', 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%1$-10I<<', 'Hello');
format
----------------
>>"Hello" <<
(1 row)
select format('>>%2$*1$L<<', 10, 'Hello');
format
----------------
>> 'Hello'<<
(1 row)
select format('>>%2$*1$L<<', 10, NULL);
format
----------------
>> NULL<<
(1 row)
select format('>>%2$*1$L<<', -10, NULL);
format
----------------
>>NULL <<
(1 row)
select format('>>%*s<<', 10, 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%*1$s<<', 10, 'Hello');
format
----------------
>> Hello<<
(1 row)
select format('>>%-s<<', 'Hello');
format
-----------
>>Hello<<
(1 row)
select format('>>%10L<<', NULL);
format
----------------
>> NULL<<
(1 row)
select format('>>%2$*1$L<<', NULL, 'Hello');
format
-------------
>>'Hello'<<
(1 row)
select format('>>%2$*1$L<<', 0, 'Hello');
format
-------------
>>'Hello'<<
(1 row)

21
src/test/regress/sql/text.sql
View File

@ -78,7 +78,8 @@ select format('%1$s %12$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
-- should fail -- should fail
select format('%1$s %4$s', 1, 2, 3); select format('%1$s %4$s', 1, 2, 3);
select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
select format('%1s', 1); select format('%0$s', 'Hello');
select format('%*0$s', 'Hello');
select format('%1$', 1); select format('%1$', 1);
select format('%1$1', 1); select format('%1$1', 1);
-- check mix of positional and ordered placeholders -- check mix of positional and ordered placeholders
@ -97,3 +98,21 @@ select format('Hello', variadic NULL);
-- variadic argument allows simulating more than FUNC_MAX_ARGS parameters -- variadic argument allows simulating more than FUNC_MAX_ARGS parameters
select format(string_agg('%s',','), variadic array_agg(i)) select format(string_agg('%s',','), variadic array_agg(i))
from generate_series(1,200) g(i); from generate_series(1,200) g(i);
-- check field widths and left, right alignment
select format('>>%10s<<', 'Hello');
select format('>>%10s<<', NULL);
select format('>>%10s<<', '');
select format('>>%-10s<<', '');
select format('>>%-10s<<', 'Hello');
select format('>>%-10s<<', NULL);
select format('>>%1$10s<<', 'Hello');
select format('>>%1$-10I<<', 'Hello');
select format('>>%2$*1$L<<', 10, 'Hello');
select format('>>%2$*1$L<<', 10, NULL);
select format('>>%2$*1$L<<', -10, NULL);
select format('>>%*s<<', 10, 'Hello');
select format('>>%*1$s<<', 10, 'Hello');
select format('>>%-s<<', 'Hello');
select format('>>%10L<<', NULL);
select format('>>%2$*1$L<<', NULL, 'Hello');
select format('>>%2$*1$L<<', 0, 'Hello');