我无法弄清楚如何从输入文件中读取字符串（单词）到链表

#include  #include  #include  struct node { char *data; struct node *next; }; void insertNode(struct node**, char *); void printList(struct node*); int main() { struct node *head = NULL; FILE *fptr; char file_name[20]; char str[1000]; int numOfChar; printf("Enter the name of the file: "); scanf("%s",file_name); printf("Enter the number of characters per line: "); scanf("%d",&numOfChar); fptr=fopen(file_name,"r"); char tokens[100]; while(fgets(str, sizeof(str), fptr) != NULL) { while (sscanf(str, "%s", tokens) != EOF) { } } fclose(fptr); printList(head); return 0; } void insertNode(struct node** nodeHead, char *data) { struct node* new_node = (struct node*) malloc(sizeof(struct node)); struct node *last = *nodeHead; char *str; str= (char *)malloc(60*sizeof(char)); strcpy(str, data); new_node->data = str; new_node->next = NULL; if (*nodeHead == NULL) { *nodeHead = new_node; return; } while (last->next != NULL) { last = last->next; } last->next = new_node; } 

我的程序应该将每个单词读入一个链表，但我无法弄清楚如何从输入文件中获取每个单词/字符串。 输入文件是ASCII文本文件。 有什么建议？ 谢谢你的帮助。

 void printList(struct node* node) { while(node != NULL) { printf(" %s ", node->data); node = node->next; } } 

Answer 1

例如，您可以使用非常低级别的字符扫描，如下例所示 – 它可能会扩展为实际接受多个分隔符，分隔符重复等：

 #include  #include  #include  int main() { FILE *fptr; char buf[100]; char *p, *s; strcpy(buf, "this is just a test"); fptr=fopen("test.txt","r"); while(fgets(buf, sizeof(buf), fptr) != NULL) { printf("LINE: %s\n", buf); /* scan characters and print tokens - single space is a separator */ p = s = buf; while(*p!=0) { if (*p==' ') { *p = 0; printf("TOKEN: %s\n", s); s = p+1; } p++; } printf("TOKEN: %s\n", s); } fclose(fptr); return 0; } 

调用可能如下所示：

 $ cat test.txt this is test1 this is test2 $ gcc tokens.c && ./a.out LINE: this is test1 TOKEN: this TOKEN: is TOKEN: test1 LINE: this is test2 TOKEN: this TOKEN: is TOKEN: test2 

Answer 2

 #include  #include  #include  struct node { char *data; struct node *next; }; void insertNode(struct node**, char *); void printList(struct node*); int main() { struct node *head = NULL; FILE *fptr; char file_name[20]; char str[1000]; int numOfChar; printf("Enter the name of the file: "); scanf("%s",file_name); printf("Enter the number of characters per line: "); scanf("%d",&numOfChar); fptr=fopen(file_name,"r"); while(fscanf(fptr, "%s ", str) != EOF) { insertNode(&head, str); } fclose(fptr); printList(head); return 0; } void insertNode(struct node** nodeHead, char *data) { struct node* new_node = malloc(sizeof *new_node); new_node->data = strdup(data); new_node->next = NULL; while (*nodeHead) nodeHead = &(*nodeHead)->next; *nodeHead = new_node; } void printList(struct node* node) { while(node != NULL) { printf(" %s ", node->data); node = node->next; } }