Say I have a const char* string like this:
../products/product_code1233213/image.jpg
I want to retrieve the second last part of this path string, which is the parent folder name of the jpg file, how would I do that?
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This might be helpful: stackoverflow.com/questions/9210528/…Ruslan– Ruslan2014-10-18 06:43:46 +00:00Commented Oct 18, 2014 at 6:43
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3 Answers
You can use strtok.
#include <string.h>
#include <stdio.h>
int main()
{
char str[] = "/products/product_code1233213/image.jpg";
char s[2] = "/";
char *token;
/* get the first token */
token = strtok(str, s);
/* walk through other tokens */
while( token != NULL )
{
printf( " %s\n", token );
token = strtok(NULL, s);
}
return(0);
}
Output:
products
product_code1233213
image.jpg
3 Comments
potrzebie
You can't use
strtok() on a constant string.
Jayesh Bhoi
@Ruslan this is called string literal and yes it's illegal to modify it.But any way OP have happy with this solution.
dulan
I did make a little tweak to make it work, by strcpy to a char*
This version works with a const char *:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main()
{
const char *s = "/products/product_code1233213/image.jpg";
const char *p = s, *begin = s, *end = s;
char *result;
size_t len;
while (p) {
p = strchr(p, '/');
if (p) {
begin = end;
end = ++p;
}
}
if (begin != end) {
len = end - begin - 1;
result = malloc(len + 1);
memcpy(result, begin, len);
result[len] = '\0';
printf("%s\n", result);
free(result);
}
return 0;
}
Comments
Using only strchr() and no backtracking. Fast and const-safe.
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SEPARATOR '/'
const char *path = "../products/product_code1233213/image.jpg";
int main(void) {
const char *beg, *end, *tmp;
beg = path;
if ((end = strchr(beg, SEPARATOR)) == NULL) {
exit(1); /* no separators */
}
while ((tmp = strchr(end + 1, SEPARATOR)) != NULL) {
beg = end + 1;
end = tmp;
}
(void) printf("%.*s\n", (int) (end - beg), beg);
return 0;
}
Comments
