Hi all,
Following is my attempt to write a string search and replace
function.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*-------------------------------------------------------------------------------------------
| Function name : strrep
|
| Arguments : src,find,rep
|
| src string should be *big* enough to hold the result
|
| Return Value : Number of replacements made |
--------------------------------------------------------------------------------------------*/
int strrep(char *src,const char *find,const char *rep)
{
char *remaining; /* pointer to the left over part
*/
int count = 0; /* no. of replacements
*/
size_t find_len = strlen(find); /* length of find string
*/
size_t rep_len = strlen(rep); /* length of replace string */
if(find_len == 0) return 0; /* nothing to find */
/*Initially allocate memory to store whole of src */
if( (remaining = malloc(strlen(src) + 1)) == NULL) /*remember to
free this*/
{
printf("Sorry out of memory !");
return 0;
}
while( (src = strstr(src,find)) != NULL ) /* get the matching
position */
{
count++; /*Count the num of
replacements*/
strcpy(remaining,src + find_len); /*store left over string
*/
strcpy(src,rep); /*make the
replacement */
src += rep_len; /*move to end of
replacement */
strcpy(src,remaining); /*copy back the left
over part */
}
free(remaining);
return count;
}
I know that this code is inefficient (it uses all the string
library routines),
I wanted to know how to improve this code. Can anyone help me ?
I want to know how you would implement the same function
I know that there are some Regex libraries to do this effectively.
But why is such a common function not there in standard library ?
Thanks for your time,
Yugi
