分段故障没有明显原因发生

Question

我没有明显的理由得到分段错误.我正在使用该strtok函数并将每一行拆分为多个标记并将它们存储在char指针中.我的数据如下:

输入:

200 -> 103 [weight=7];
200 -> 153 [weight=27];
200 -> 53 [weight=9];
200 -> 178 [weight=43];
55 -> 2 [weight=23];
55 -> 14 [weight=50];
55 -> 20 [weight=17];
55 -> 22 [weight=1];
55 -> 74 [weight=7];
55 -> 93 [weight=9];
55 -> 122 [weight=27];
65 -> 8 [weight=27];
65 -> 9 [weight=9];

码:

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

int main(int argc,char **argv)
{
        char *ipfile,line[80];
        FILE *fp;
        char *field1,*field2,*field3,*field4,*field5,*field6,mystr[10];
        int row,column,weight;
        ipfile = (char *)argv[1];
        printf("The input file name is %s\n",ipfile);
        fp = fopen(ipfile,"r");

        if(fp ==NULL) //Checking whether the command line argument was correctly or not.
        printf("There is no such file in the directory.\n");

        while(fgets(line,80,fp) != NULL)
        {
                field1 = strtok(line," ");
                //row    = atoi(field1);
                field2 = strtok(NULL," ");
                field3 = strtok(NULL," ");
                //column = atoi(field3);
                field4 = strtok(NULL," ");
                field5 = strtok(NULL," ");
                //field6 = strtok(NULL," ");

                printf("%s\n",field5);
                //printf("Row-%d Column - %d Weight - %d\n",row,column,weight);
        }
        fclose(fp);
        return 0;
}

来自评论:

当我尝试打印field1,field2,field3,field4之后就被打印出来.但是,当我尝试field5和field6我的节目是给分段错误.

在SO用户的建议之后添加代码.

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

int main(int argc,char **argv)
{
        char *ipfile,line[80];
        FILE *fp;
        char *field1,*field2,*field3,*field4,*field5,*field6,mystr[10];
        int row,column,weight;
        ipfile = (char *)argv[1];
        printf("The input file name is %s\n",ipfile);
        fp = fopen(ipfile,"r");

        if(fp == NULL) //Checking whether the command line argument was correctly or not.
        printf("There is no such file in the directory.\n");

        while(fgets(line,80,fp) != NULL)
        {
                field1 = strtok(line," ");
                //row    = atoi(field1);
                field2 = strtok(NULL," ");
                field3 = strtok(NULL," ");
                //column = atoi(field3);
                field4 = strtok(NULL," ");
                field5 = strtok(NULL," []=;");
                //field6 = strtok(NULL," ");

                printf("%s\n",field5);
                //printf("Row-%d Column - %d Weight - %d\n",row,column,weight);
        }
        fclose(fp);
        return 0;
}

Answer 1

你在空格上拆分字符串,所以这只有4个令牌,而你的代码需要6个:

200 -> 103 [weight=7];

指定" []=;"为分隔符以解决此问题.(或者->当你在它时也包括在内.)