addaword.c

c primer plus 第五版 的源代码

/* addaword.c -- uses fprintf(), fscanf(), and rewind() */
#include <stdio.h>
#include <stdlib.h>
#define MAX 40

int main(void)
{
    FILE *fp;
    char words[MAX];

    if ((fp = fopen("wordy", "a+")) == NULL)
    {
        fprintf(stdout,"Can't open \"words\" file.\n");
        exit(1);
    }
     
    puts("Enter words to add to the file; press the Enter");
    puts("key at the beginning of a line to terminate.");
    while (gets(words) != NULL  && words[0] != '\0')
        fprintf(fp, "%s ", words);
     
    puts("File contents:");
    rewind(fp);           /* go back to beginning of file */
    while (fscanf(fp,"%s",words) == 1)
        puts(words);
     
    if (fclose(fp) != 0)
        fprintf(stderr,"Error closing file\n");
     
    return 0;
}