Add support for * precision in printf()

Author: nikic

ext/standard/formatted_print.c

@@ -364,6 +364,27 @@ php_sprintf_getnumber(char **buffer, size_t *len)
 }
 /* }}} */
 
+#define ARG_NUM_NEXT -1
+#define ARG_NUM_INVALID -2
+
+int php_sprintf_get_argnum(char **format, size_t *format_len) {
+	char *temppos = *format;
+	while (isdigit((int) *temppos)) temppos++;
+	if (*temppos != '$') {
+		return ARG_NUM_NEXT;
+	}
+
+	int argnum = php_sprintf_getnumber(format, format_len);
+	if (argnum <= 0) {
+		zend_value_error("Argument number must be greater than zero");
+		return ARG_NUM_INVALID;
+	}
+
+	(*format)++;  /* skip the '$' */
+	(*format_len)--;
+	return argnum - 1;
+}
+
 /* php_formatted_print() {{{
  * New sprintf implementation for PHP.
  *
@@ -438,24 +459,12 @@ php_formatted_print(char *format, size_t format_len, zval *args, int argc, int n
 						  *format, format - Z_STRVAL_P(z_format)));
 			if (isalpha((int)*format)) {
 				width = precision = 0;
-				argnum = currarg++;
+				argnum = ARG_NUM_NEXT;
 			} else {
 				/* first look for argnum */
-				temppos = format;
-				while (isdigit((int)*temppos)) temppos++;
-				if (*temppos == '$') {
-					argnum = php_sprintf_getnumber(&format, &format_len);
-
-					if (argnum <= 0) {
-						zend_string_efree(result);
-						zend_value_error("Argument number must be greater than zero");
-						return NULL;
-					}
-					argnum--;
-					format++;  /* skip the '$' */
-					format_len--;
-				} else {
-					argnum = currarg++;
+				argnum = php_sprintf_get_argnum(&format, &format_len);
+				if (argnum == ARG_NUM_INVALID) {
+					goto fail;
 				}
 
 				/* after argnum comes modifiers */
@@ -503,11 +512,38 @@ php_formatted_print(char *format, size_t format_len, zval *args, int argc, int n
 					format++;
 					format_len--;
 					PRINTF_DEBUG(("sprintf: getting precision\n"));
-					if (isdigit((int)*format)) {
+					if (*format == '*') {
+						format++;
+						format_len--;
+
+						int prec_argnum = php_sprintf_get_argnum(&format, &format_len);
+						if (prec_argnum == ARG_NUM_INVALID) {
+							goto fail;
+						}
+						if (prec_argnum == ARG_NUM_NEXT) {
+							prec_argnum = currarg++;
+						}
+						if (prec_argnum >= argc) {
+							max_missing_argnum = MAX(max_missing_argnum, prec_argnum);
+							continue;
+						}
+						tmp = &args[prec_argnum];
+						ZVAL_DEREF(tmp);
+						if (Z_TYPE_P(tmp) != IS_LONG) {
+							zend_value_error("Precision must be an integer");
+							goto fail;
+						}
+						if (Z_LVAL_P(tmp) < -1 || Z_LVAL_P(tmp) > INT_MAX) {
+							zend_value_error("Precision must be between -1 and %d", INT_MAX);
+							goto fail;
+						}
+						precision = Z_LVAL_P(tmp);
+						adjusting |= ADJ_PRECISION;
+						expprec = 1;
+					} else if (isdigit((int)*format)) {
 						if ((precision = php_sprintf_getnumber(&format, &format_len)) < 0) {
-							efree(result);
 							zend_value_error("Precision must be greater than zero and less than %d", INT_MAX);
-							return NULL;
+							goto fail;
 						}
 						adjusting |= ADJ_PRECISION;
 						expprec = 1;
@@ -526,11 +562,19 @@ php_formatted_print(char *format, size_t format_len, zval *args, int argc, int n
 			}
 			PRINTF_DEBUG(("sprintf: format character='%c'\n", *format));
 
+			if (argnum == ARG_NUM_NEXT) {
+				argnum = currarg++;
+			}
 			if (argnum >= argc) {
 				max_missing_argnum = MAX(max_missing_argnum, argnum);
 				continue;
 			}
 
+			if (expprec && precision == -1 && *format != 'g' && *format != 'G') {
+				zend_value_error("Precision -1 is only supported for %%g and %%G");
+				goto fail;
+			}
+
 			/* now we expect to find a type specifier */
 			tmp = &args[argnum];
 			switch (*format) {
@@ -641,6 +685,10 @@ php_formatted_print(char *format, size_t format_len, zval *args, int argc, int n
 	ZSTR_VAL(result)[outpos]=0;
 	ZSTR_LEN(result) = outpos;
 	return result;
+
+fail:
+	zend_string_efree(result);
+	return NULL;
 }
 /* }}} */
 

ext/standard/tests/strings/sprintf_star.phpt

@@ -0,0 +1,54 @@
+--TEST--
+Star width and precision in sprintf()
+--FILE--
+<?php
+
+
+$f = 1.23456789012345678;
+var_dump($f);
+printf("%.*f\n", 10, $f);
+printf("%.*G\n", 10, $f);
+printf("%.*G\n", -1, $f);
+printf("%.*s\n", 3, "foobar");
+
+echo "\n";
+
+printf("%1$.*2\$f\n", $f, 10);
+printf("%.*2\$f\n", $f, 10);
+printf("%2$.*f\n", 10, $f);
+
+echo "\n";
+
+try {
+    printf("%.*G\n", "foo", 1.5);
+} catch (ValueError $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    printf("%.*G\n", -100, 1.5);
+} catch (ValueError $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    printf("%.*s\n", -1, "Foo");
+} catch (ValueError $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECTF--
+float(1.2345678901234567)
+1.2345678901
+1.23456789
+1.2345678901234567
+foo
+
+1.2345678901
+1.2345678901
+1.2345678901
+
+Precision must be an integer
+Precision must be between -1 and 2147483647
+Precision -1 is only supported for %g and %G