c - 如何在 for 循环中使用 strtok()？

Question

对于给定的表示，

typedef struct {
  int age;
  char *firstName;
  char *lastName;
}Record;

---

并给定file.txt，

Age,LastName,FirstName
50,B,A
30,A,B
20,X,D
10,F,A
90,V,E
60,N,M

---

下面是main()中的代码，

 pFile=fopen("file.txt", "r");
 ...
 //Complete file is copied to 'readBuffer', approach inspired from  
 // http://stackoverflow.com/a/11487960/3317808
 ....

 char *record = strtok(readBuffer,"\n"); //Ignore header record
  record = strtok(NULL, "\n");// Read first data record(50,'B','A')

  for(;record != NULL; record = strtok(NULL,"\n")){

    printf("###Print complete record\n");
    puts(record);

    Record *r = malloc(sizeof(Record)*1);

    r->age = atoi(strtok(record,","));

    char *firstName = strtok(NULL,",");
    char *lastName = strtok(NULL, ",");

    r->firstName = strdup(firstName);
    r->lastName = strdup(lastName);
    printf("Age: %d\n", r->age);
    printf("First name: %s\n", r->firstName);
    printf("Last name: %s\n", r->lastName);

  }

---

strtok(readBuffer,",")将编译器与 for 循环中的 strtok(record,",") 混淆

---

实际输出显示标记化只发生在一条记录上。

$ ./program.exe
Print complete file
Age,LastName,FirstName
50,B,A
30,A,B
20,X,D
10,F,A
90,V,E
60,N,M



###Print complete record
50,B,A
Age: 50
First name: B
Last name: A

---

如何解决？

Answer 1

如果在我们的例子中可能的话，使用 strtok_r() 似乎是最简单的方法。只是通知一下，这不是标准 C，它在 POSIX 中。

来自man page ,

The strtok_r() function is a reentrant version strtok(). The saveptr argument is a pointer to a char * variable that is used internally by strtok_r() in order to maintain context between successive calls that parse the same string.

和

Different strings may be parsed concurrently using sequences of calls to strtok_r() that specify different saveptr arguments.

手册页还有您正在寻找的场景的示例。