fscanf在C中两次从文件复制一行

Question

                while(1<2) {
                    nscan=fscanf(infile, "%s %s %d%c",temp.name, temp.surname,&temp.code,&termch);
                    if(nscan==EOF) break;
                    if(nscan!=4 || termch!='\n')
                        printf("Error\n");
                    RecBSTInsert(&a,temp);

             }

for some reason nscan //if(nscan==EOF) break; does not get executed when it is supposed to and it runs one more time giving the binary tree one more value, which is same with the last one.

Answer 1

fscanf:

Upon successful completion, these functions shall return the number of successfully matched and assigned input items.

fscanf does not return the input provided. That is why you are not seeing EOF like you are testing for.

See: manpage for *scanf functions.

---

To answer your other question, try looping through like this:

while (fscanf(infile, "%s %s %d%c, temp.name, temp.surname, &temp.code, &termch) == 4)
{
    //...
}

---

Edit again: I threw together a small program to simulate what I think you are doing. Here is my implementation, which takes from a file "testfile.txt" which looks like:

Bill Person 1

Bob Dog 2

Andrew Cat 3

With only one newline between each line. It matches the pattern %s %s %d%c (where \\n is the %c).

Program to use this file:

#include <stdio.h>
#include <stdlib.h>

struct test {
    char name[64];
    char surname[64];
    int code;
};

int main()
{
    struct test temp;
    char endchar;
    FILE *infile = fopen("./testfile.txt", "r+"); // works with "r" as well, just a habit
    if (infile == NULL)
        return -1;
    while (fscanf(infile, "%s %s %d%c", temp.name, temp.surname, 
                  &temp.code, &endchar) == 4)
    {
        printf("Got one!\n");
    }
    return 0;
}

Of course, the printf exists in place of whatever logic you want to do on the current "temp" input.