c - strtok 和数组存储 : output not as expected

Question

在下面的代码中，文件 test.txt 具有以下数据:
192.168.1.1-90
192.168.2.2-80

这个输出不符合预期。我期望输出是
192.168.1.1
90
192.168.2.2
80
任何帮助将不胜感激。

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
int main()
{
  FILE *fp;
  char *result[10][4];
  int i=0;
  const char s[2] = "-";
  char *value,str[128];
  fp = fopen("test.txt", "r");
  if (fp == NULL)
    printf("File doesn't exist\n");
  else{
    while(!feof(fp)){

      if(fgets(str,sizeof(str),fp)){

        /* get the first value */
        value = strtok(str, s);
        result[i][0]=value;
        printf("IP : %s\n",result[i][0]); //to be removed after testing


        /* get second value */
        value = strtok(NULL, s);
        result[i][1]=value;
        printf("PORT : %s\n",result[i][1]); //to be removed after testing
        i++;
     }}
    for (int k=0;k<2;k++){
        for (int j=0;j<2;j++){
            printf("\n%s\n",result[k][j]);
       }
   }

 }
        return(0);
 }

Answer 1

您可以尝试这个解决方案。它使用动态内存来代替，但会做你想要的事情。

代码:

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

#define BUFFSIZE 128

void exit_if_null(void *ptr, const char *msg);

int
main(int argc, char const *argv[]) {
    FILE *filename;
    char buffer[BUFFSIZE];
    char *sequence;
    char **ipinfo;
    int str_size = 10, str_count = 0, i;

    filename = fopen("ips.txt", "r");

    if (filename == NULL) {
        fprintf(stderr, "%s\n", "Error Reading File!");
        exit(EXIT_FAILURE);
    }

    ipinfo = malloc(str_size * sizeof(*ipinfo));
    exit_if_null(ipinfo, "Initial Allocation");

    while (fgets(buffer, BUFFSIZE, filename) != NULL) {
        sequence = strtok(buffer, "-\n");

        while (sequence != NULL) {
            if (str_size == str_count) {
                str_size *= 2;
                ipinfo = realloc(ipinfo, str_size * sizeof(*ipinfo));
                exit_if_null(ipinfo, "Reallocation");
            }

            ipinfo[str_count] = malloc(strlen(sequence)+1);
            exit_if_null(ipinfo[str_count], "Initial Allocation");

            strcpy(ipinfo[str_count], sequence);

            str_count++;

            sequence = strtok(NULL, "-\n");
        }
    }

    for (i = 0; i < str_count; i++) {
        printf("%s\n", ipinfo[i]);
        free(ipinfo[i]);
        ipinfo[i] = NULL;
    }

    free(ipinfo);
    ipinfo = NULL;

    fclose(filename);

    return 0;
}

void
exit_if_null(void *ptr, const char *msg) {
    if (!ptr) {
        printf("Unexpected null pointer: %s\n", msg);
        exit(EXIT_FAILURE);
    }
}