在C中用scanf分割字符串

Question

I have a string that has # and ! symbols throughout it. My task is to separate all the content in between those symbols into new strings. I don't know how many symbols there are going to be.

Can I use the scanf function to separate them into strings

I was thinking something like this:

input string: dawddwamars#dawdjiawjd!fjejafi!djiajoa#jdawijd#

char s1[20], s2[20], s3[20], s4[20], s5[20];

scanf("%s[^!][^#]%s[^!][^#]%s[^!][^#]%s[^!][^#]%s[^!][^#]", s1, s2, s3, s4, s5);

Would this work? Or does someone have a method that is better. I need to separate the string into substrings because i have to search for the longest common substring in those new strings.

Answer 1

To get you started, here is some non-flexible code concerning number of substrings you will get out of the input string (strings array). As already mentioned, use strsep() (since strtok() is obsoleted by it, see man strtok ).

#include <stdio.h>
#include <string.h>

int main() {
    char* str;
    char* token;
    char* temp;
    char strings[10][20];
    int i = 0;
    str = strdup("dawddwamars#dawdjiawjd!fjejafi!djiajoa#jdawijd#");

    printf("%s\n", str);
    while ((token = strsep(&str, "#")) != NULL) {
        temp = strdup(token);
        while ((token = strsep(&temp, "!")) != NULL) {
            printf("%s\n", token);
            strcpy(strings[i], token);
            i++;
        }
    }
}

Answer 2

scanf() has a lot of features that just aren't needed here.

To be more efficient, I would probably use strtok() , which seems ideal for this task.

Alternatively, I might just write C code to find the next # or ! using strchr() or a simple loop, and then just extract the tokens myself.

Answer 3

If you must use scanf()

#define Fmt1   "%19[^#!]"
#define Sep1   "%*[#!]"
char s1[20], s2[20], s3[20], s4[20], s5[20];
int count = scanf(" " Fmt1 Sep1 Fmt1 Sep1 Fmt1 Sep1 Fmt1 Sep1 Fmt1, 
    s1, s2, s3, s4, s5);
// count represents the number of successfully scanned strings.
// Expected range 0 to 5 and EOF.