c - 如何知道C中的行尾

Question

如果我做 :

int main(){
    const int LENGTH_LINE = 100;
    char line[LENGTH_LINE];
    int len;
    FILE* fp = fopen(file.txt,"r");

    fgets(line,LENGTH_LINE,fp);
    len = strlen(line);
    if(line[len-1] == '\n')
       printf("I've a line");

    //This work if the line have \n , but if the end line of the text dont have \n how can do it?


}

我需要知道我是否用 fgets 整整一行因为我有一个分隔符。

Answer 1

根据 http://en.cppreference.com/w/c/io/fgets

Reads at most count - 1 characters from the given file stream and stores them in str. 
Parsing stops if end-of-file occurs or a newline character is found, in which case str will contain that newline character.

所以，一旦 fgets 返回，就有 3 种可能性

已达到 LENGTH_LINE

我们得到了一个换行符

达到EOF。

我假设您在案例 2 和案例 3 中有一条线。

在这种情况下，检测条件是:

line[len-1] == '\n' || feof(fp)