<?php
$object = "dizaz#7#final";
$res = str_replace("#", "-", $object);
echo $res;

/* {{{ proto mixed str_replace(mixed search, mixed replace, mixed subject [, int &replace_count])
Replaces all occurrences of search in haystack with replace */
PHP_FUNCTION(str_replace)
{
php_str_replace_common(INTERNAL_FUNCTION_PARAM_PASSTHRU, 1);

}
/* }}} */

/* {{{ php_str_replace_common
*/
static void php_str_replace_common(INTERNAL_FUNCTION_PARAMETERS, int case_sensitivity)
{
/**
* TODO
* typedef struct _zval_struct zval;
* typedef struct _zend_class_entry zend_class_entry
*
* struct _zval_struct {
* zvalue_value value;
* zend_uint refcount__gc;
* zend_uchar type;
* zend_uchar is_ref__gc;
* };
*
* typedef union _zvalue_value {
* long lval;
* double dval;
* struct {
* char *val;
* int len;
* } str;
* HashTable *ht;
* zend_object_value obj;
* } zvalue_value;
*
* typedef struct _zend_object {
* zend_class_entry *ce;
* HashTable *properties;
* HashTable *guards;
* } zend_object;
*
*/
zval **subject, **search, **replace, **subject_entry, **zcount = NULL;
zval *result;
char *string_key;
uint string_key_len;
ulong num_key;
int count = 0;
int argc = ZEND_NUM_ARGS();
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ZZZ|Z", &search, &replace, &subject, &zcount) == FAILURE) {
return;
}
SEPARATE_ZVAL(search);
SEPARATE_ZVAL(replace);
SEPARATE_ZVAL(subject);
/* Make sure we're dealing with strings and do the replacement. */
if (Z_TYPE_PP(search) != IS_ARRAY) {
....//代碼省濾
} else { /* if subject is not an array */
php_str_replace_in_subject(*search, *replace, subject, return_value, case_sensitivity, (argc > 3) ? &count : NULL);
}
if (argc > 3) {
zval_dtor(*zcount);
ZVAL_LONG(*zcount, count);
}
}
/* }}} */

/* {{{ php_str_replace_in_subject
*/
static void php_str_replace_in_subject(zval *search, zval *replace, zval **subject, zval *result, int case_sensitivity, int *replace_count)
{
zval **search_entry,
**replace_entry = NULL,
temp_result;
char *replace_value = NULL;
int replace_len = 0;
/* Make sure we're dealing with strings. */
convert_to_string_ex(subject);
Z_TYPE_P(result) = IS_STRING;
if (Z_STRLEN_PP(subject) == 0) {
ZVAL_STRINGL(result, "", 0, 1);
return;
}
/* If search is an array */
if (Z_TYPE_P(search) == IS_ARRAY) {
...//不走這步
} else {
if (Z_STRLEN_P(search) == 1) { //例子中只有”#“所以，執(zhí)行這一步。
php_char_to_str_ex(Z_STRVAL_PP(subject),//subject的值，也就是dizaz#7#final
Z_STRLEN_PP(subject), //獲取subject的長度
Z_STRVAL_P(search)[0], //由于只有1個(gè)”#”，所以只需要第一個(gè)字符
Z_STRVAL_P(replace), //所要替換成的字符，現(xiàn)在是“-”
Z_STRLEN_P(replace), //目標(biāo)字符的長度，現(xiàn)在為1
result, //替換結(jié)果
case_sensitivity, //大小寫是否敏感，默認(rèn)是1
replace_count); //替換次數(shù)
} else if (Z_STRLEN_P(search) > 1) {
Z_STRVAL_P(result) = php_str_to_str_ex(Z_STRVAL_PP(subject), Z_STRLEN_PP(subject),
Z_STRVAL_P(search), Z_STRLEN_P(search),
Z_STRVAL_P(replace), Z_STRLEN_P(replace), &Z_STRLEN_P(result), case_sensitivity, replace_count);
} else {
MAKE_COPY_ZVAL(subject, result);
}
}
}

/* {{{ php_char_to_str_ex
*/
PHPAPI int php_char_to_str_ex(char *str, uint len, char from, char *to, int to_len, zval *result, int case_sensitivity, int *replace_count)
{
int char_count = 0;
int replaced = 0;
char *source, *target, *tmp, *source_end=str+len, *tmp_end = NULL;
if (case_sensitivity) { //現(xiàn)在case_sensitivity = 1
char *p = str, *e = p + len;
　　　　　//計(jì)算需要替換幾次
while ((p = memchr(p, from, (e - p)))) {
char_count++;
p++;
}
} else {
for (source = str; source < source_end; source++) {
if (tolower(*source) == tolower(from)) {
char_count++;
}
}
}
if (char_count == 0 && case_sensitivity) {
ZVAL_STRINGL(result, str, len, 1);
return 0;
}
//計(jì)算替換以后的長度，并且存儲(chǔ)到result中。
Z_STRLEN_P(result) = len + (char_count * (to_len - 1));
//申請(qǐng)內(nèi)存，存放替換后的數(shù)據(jù)
Z_STRVAL_P(result) = target = safe_emalloc(char_count, to_len, len + 1);
//設(shè)定結(jié)果是一個(gè)字符串
Z_TYPE_P(result) = IS_STRING;
//target跟result的值都指向統(tǒng)一塊內(nèi)存，所以只需要處理target
if (case_sensitivity) {
char *p = str, *e = p + len, *s = str;
while ((p = memchr(p, from, (e - p)))) { //判斷在第幾個(gè)字符出現(xiàn)#
memcpy(target, s, (p - s)); //把#以前的數(shù)據(jù)拷貝給target
target += p - s;
memcpy(target, to, to_len); //把目標(biāo)字符拷貝給target[當(dāng)然此時(shí)的target是開始target+p-s的]
target += to_len;
p++;
s = p;
if (replace_count) {
*replace_count += 1; //設(shè)定替換次數(shù)
}
}
//如果后面還有，繼續(xù)添加到target后，這樣target所指向的內(nèi)存塊已經(jīng)是替換好的數(shù)據(jù)了。
if (s < e) {
memcpy(target, s, (e - s));
target += e - s;
}
} else {
for (source = str; source < source_end; source++) {
if (tolower(*source) == tolower(from)) {
replaced = 1;
if (replace_count) {
*replace_count += 1;
}
for (tmp = to, tmp_end = tmp+to_len; tmp < tmp_end; tmp++) {
*target = *tmp;
target++;
}
} else {
*target = *source;
target++;
}
}
}
*target = 0;
return replaced;
}
/* }}} */