一个C语言程序输出序号和单词,#include #include #define MAX 40int main(void){FILE *fp;char words[MAX];int wordct = 0;if ((fp = fopen("wordy","a+")) == NULL){fprintf(stderr,"Can't open \"words\" file.\n");exit(1);}/* determine current numbe

一个C语言程序输出序号和单词,#include #include #define MAX 40int main(void){FILE *fp;char words[MAX];int wordct = 0;if ((fp = fopen("wordy","a+")) == NULL){fprintf(stderr,"Can't open \"words\" file.\n");exit(1);}/* determine current numbe
一个C语言程序输出序号和单词,
#include
#include
#define MAX 40
int main(void)
{
FILE *fp;
char words[MAX];
int wordct = 0;
if ((fp = fopen("wordy","a+")) == NULL)
{
fprintf(stderr,"Can't open \"words\" file.\n");
exit(1);
}
/* determine current number of entries */
rewind(fp);
while (fgets(words,MAX - 1,fp) = NULL)
wordct++;
rewind(fp);
puts("Enter words to add to the file.Enter one word per line,and ");
puts("press the Enter key at the beginning of a line to terminate.");
while (gets(words) = NULL && words[0] = '\0')
fprintf(fp,"%d:%s\n",++wordct,words);
puts("File contents:");
rewind(fp); /* go back to beginning of file */
while (fgets(words,MAX - 1,fp) = NULL)
fputs(words,stdout);
if (fclose(fp) = 0)
fprintf(stderr,"Error closing file\n");
return 0;}尤其是解释一下rewind();谢谢!

一个C语言程序输出序号和单词,#include #include #define MAX 40int main(void){FILE *fp;char words[MAX];int wordct = 0;if ((fp = fopen("wordy","a+")) == NULL){fprintf(stderr,"Can't open \"words\" file.\n");exit(1);}/* determine current numbe
#include
#include
#define MAX 40
int main(void)
{
FILE *fp;
char words[MAX];
int wordct = 0;
if ((fp = fopen("wordy","a+")) == NULL) //打开文件,是指针fp指向文件wordy
{
fprintf(stderr,"Can't open \"words\" file.\n");
exit(1);
}
/* determine current number of entries */
rewind(fp); //rewind()是一个反绕函数,作用是使指针回到文件的开头,在对文件读写的过程中,指针是一直变化的,但是这个函数会把指针重新置在文件的开头
while (fgets(words,MAX - 1,fp) != NULL) // 统计文件中单词个数
wordct++;
rewind(fp);
puts("Enter words to add to the file.Enter one word per line,and ");
puts("press the Enter key at the beginning of a line to terminate.");
while (gets(words) != NULL && words[0] != '\0')
fprintf(fp,"%d:%s\n",++wordct,words); //追加新单词到文件中,并标注序号wordct
puts("File contents:");
rewind(fp); /* go back to beginning of file */
while (fgets(words,MAX - 1,fp) != NULL)
fputs(words,stdout);
if (fclose(fp) != 0)
fprintf(stderr,"Error closing file\n");
return 0;}