pointer proggy

I need to write an implementation for search that steps through the string comparing each character wit the given character. If it finds a match, it will return a pointer to the current position. If it reaches the end of the string without finding a match, it will return a null pointer.

Can anyone help me do it?

Here is my code so far:#include <stdio.h>

char* search (char* s, int c) {

/*code here*/


}

int main () {
char quick_fox [] = "The quick brown fox jumps over the lazy dog.";
char c;
char* p;

c = 'x';
p = search(quick_fox, c);
if (p) {
printf("The substring that starts with %c is \"%s\"\n", c, p);
} else {
printf("No %c in \"%s\"\n", c, quick_fox);
}

c = 'X';
p = search(quick_fox, c);
if (p) {
printf("The substring that starts with %c is \"%s\"\n", c, p);
} else {
printf("No %c in \"%s\"\n", c, quick_fox);
}
}

what about the standard strchr function?

The manual page: strchr

You need a temporary pointer that points to the beginning of the string. You can increment the temporary pointer (++) and get the character to where the temporary pointer is pointing by placing a * before it (it's called dereferencing). Just loop through the string and stop when you find a match or when you are at the end of the string. Here a beginning of the search function. You only have to fill in the while and if statement and you're done.

Code:

---

char* search (char* s, int c)
{
    char *tmp = s;

    if(tmp != NULL)
    {
        while( /* while not end of string and no match with c */ )
            tmp++;

        if( /* if at end of string then return NULL pointer */ )
            tmp = NULL;
    }
    return tmp;
}

---

Here an example of dereferencing:

Code:

---

int main(void)
{
    char s[] = "Hello world\n";
    char *tmp = s;

    while(*tmp != '\0') /* while not end of string */
    {
        printf("%c", *tmp); /* print character */
        tmp++;
    }
    return 0;
}

---