与声明的 int 函数冲突的类型

Question

阅读 Kernigan，由于用户函数的“冲突类型”错误，给定的代码似乎不起作用。

我使用的编译器是cc 7.4.0。我一开始就声明了函数，并且似乎一直在检查和重新检查类型。我猜我漏掉了什么。

#include <stdio.h>
#define MAXLINE 1000

int getline(char line[], int maxline);

main()
{
    int len;
    char line[MAXLINE];

    while((len = getline(line, MAXLINE)) > 0)
        ;
    return 0;
}

int getline(char s[], int lim)
{
    int i, c;

    for (i = 0; i < (lim-1) && (c = getchar())!=EOF && c != '\n'; ++i)
        s[i] = c;
    if (c == '\n') {
        s[i] = c;
        ++i;
    }
    s[i] = '\0';
    return i;
}

我得到的错误是

func.c:4:5: error: conflicting types for ‘getline’
 int getline(char line[], int maxline);
     ^~~~~~~
In file included from func.c:1:0:
/usr/include/stdio.h:616:20: note: previous declaration of ‘getline’ was here
 extern _IO_ssize_t getline (char **__restrict __lineptr,
                    ^~~~~~~
 ^~~~
func.c:25:5: error: conflicting types for ‘getline’
 int getline(char s[], int lim)
     ^~~~~~~
In file included from func.c:1:0:
/usr/include/stdio.h:616:20: note: previous declaration of ‘getline’ was here
 extern _IO_ssize_t getline (char **__restrict __lineptr,

Answer 1

getline已在 <stdio.h> 中声明(实际上是错误的)并且它的签名与你的不同。

最简单的做法是将您的版本重命名为不同的名称。