str_replace for C
2399 ワード
////PS
char *str_replace(const char *search ,const char *replace ,const char *subject)
{
int i = 0;
char *str = strdup(subject);
char *p = str;
char *new_str;
char *p1;
int len = strlen(str);
while((p = strstr(p,search)))
{
*p = '\0';
p+=strlen(search);
++i;
}
if(i < 1)
{
free(str);
return NULL;
}
new_str = (char *)malloc(i * strlen(replace) + strlen(subject));
*new_str = 0;
p1 = new_str;
p = str;
for (p = str;(int)p - (int)str < len;)
{
if(*p == '\0')
{
strcat(p1,replace);
p += strlen(search);
p1 += strlen(replace);
}
else
{
*p1++ = *p++;
*p1 = 0;
}
}
free(str);
return new_str;
}
//////////////////////////////////////////////////////////////////////////////////////////////
http://www.binarytides.com/str_replace-for-c/
Php has a useful function called str_replace which can search and
replace a certain string in another big string. However there is no such
function in C. So I wrote up one for myself. Here is the code.
/*
* Search and replace a string with another string , in a string
* */
char *str_replace(char *search , char *replace , char *subject)
{
char *p = NULL , *old = NULL , *new_subject = NULL ;
int c = 0 , search_size;
search_size = strlen(search);
//Count how many occurences
for(p = strstr(subject , search) ; p != NULL ; p = strstr(p + search_size , search))
{
c++;
}
//Final size
c = ( strlen(replace) - search_size )*c + strlen(subject);
//New subject with new size
new_subject = malloc( c );
//Set it to blank
strcpy(new_subject , "");
//The start position
old = subject;
for(p = strstr(subject , search) ; p != NULL ; p = strstr(p + search_size , search))
{
//move ahead and copy some text from original subject , from a certain position
strncpy(new_subject + strlen(new_subject) , old , p - old);
//move ahead and copy the replacement text
strcpy(new_subject + strlen(new_subject) , replace);
//The new start position after this search match
old = p + search_size;
}
//Copy the part after the last search match
strcpy(new_subject + strlen(new_subject) , old);
return new_subject;
}