使用strstr逐行搜索

Question

我一直试图提出一种系统，该系统逐行搜索文件中的6位数字，当它找到它时，它将中断循环并输出找到的行，但是由于某种原因，每当我运行我的尝试时该程序刚刚退出。任何帮助，将不胜感激

        searching = 1;
        while (searching == 1) {
            search = 0;
            printf("Please enter the UP number of the student:\n");
            scanf(" %d", &w);
            while (search != 1) {
                fgets(line, 60, StudentDB);
                t = strstr(line, w);
                if (t != NULL && t != -1) {
                    search = 1;
                    printf("The student's data is:\n");
                    printf("%s\n", line);
                    printf("What would you like to do now\n1. Edit marks\n2. Delete record\n3. Search for a different record\n4. Return to menu\n");
                    scanf(" %d", &v);
                    switch (v)
                    case 1:

                    case 2:

                    case 3:
                        break;
                    case 4:
                        ;
                        break;
                    }
               if (line == EOF) {
                    search = 1;
                    printf("There is no student with that UP number saved.\nWhat would you like to do?\n");
                    printf("1. Search for a different number\n2. Return to the menu\n");
                    scanf(" %d", &v);
                    switch (v) {
                        case 1:
                            break;
                        case 2:
                            searching = 0;
                            search = 1;
                            break;
                        }
                } else {
                    printf("Something went horribly horribly wrong");
                }
                break;
            }
        }

Answer 1

您无法使用t = strstr(line, w);搜索号码

strstr的第二个参数必须是字符串。您应该将w定义为char w [7];, read the 6 digit number as a string withscanf（“％6s”，w）and use strstr（line，w）`以在行中查找编号。

[还要注意，t != -1毫无意义，t应该是char *，如果不存在该数字，则为NULL；如果找到strstr，则为指向该行的有效指针。] >

类似地，在搜索行之后测试文件末尾没有任何意义：在文件末尾，fgets()返回NULL并且未读取该行。