K＆安培; R运动1-16铛 - 冲突的类型函数getline [英] K&R Exercise 1-16 clang - conflicting types for getline

问题描述

我通过K＆放工作; R，使用锵为我的编译器

在铿锵编译练习1-16产生冲突的类型'函数getline'的错误。我猜，因为默认库中的一个具有getline函数的。

我应该通过什么选项锵编译K＆放时;被列入ř练习以免别的

要修改的练习样本：

 的#include＆LT;＆stdio.h中GT;
＃定义MAXLINE 1000INT函数getline（焦线[]，INT MAXLINE）;
无效副本（字符为[]，在[]字符）;/ *打印最长一行* /
主要（）
{
  INT LEN; / *当前行的长度* /
  INT最大; / *最大线lenght迄今为止看到的* /
  焦线[MAXLINE] / *当前输入行* /
  烧焦最长[MAXLINE] / *最长行保存在这里* /  最大= 0;  而（（LEN =函数getline（线，MAXLINE））大于0）
    如果（LEN＆GT;最大）{
      最大= LEN;
      副本（最长的，行）; / *线 - ＆GT;最长的* /
    }  如果（最大值大于0）/ *有一个线路* /
    的printf（\\ n \\ nLength数：％d \\ nString：％S，最大-1，最长的）;
  返回0;
}/ *函数getline：读取一行到s，返回长度* /
INT函数getline（char中[]，INT LIM）
{
  INT C，I;  对于（i = 0; I＆LT; LIM-1安培;及（C =的getchar（））= EOF和放大器;！＆安培;！C ='\\ n'; ++ I）
    S [i] = C;  如果（C =='\\ n'）{
    S [i] = C;
    ++我;
  }  S [我] ='\\ 0';
  返回我;
}/ *副本：副本，从进到;承担足够大* /
无效副本（字符为[]，在[]字符）
{
  INT I;  I = 0;  而（（在[I] =从[I]）！='\\ 0'）
    ++我;
}
 

这锵的错误，当调用为： CC ex1-16.c -o ex1-16

  ex1-16.c：4：5：错误：冲突的类型'函数getline
INT函数getline（焦线[]，INT MAXLINE）;
    ^
/usr/include/stdio.h:449:9：注意：previous声明是在这里
ssiz​​e_t供函数getline（字符** __restrict，为size_t * __restrict，FILE * ...
        ^
ex1-16.c：17：38：错误：太少参数函数调用，预计3，有2个
  而（（LEN =函数getline（线，MAXLINE））大于0）
                ~~~~~~~ ^
/usr/include/stdio.h:449:1：注意：函数getline在这里声明
ssiz​​e_t供函数getline（字符** __restrict，为size_t * __restrict，FILE * ...
^
ex1-16.c：29：5：错误：冲突的类型'函数getline
INT函数getline（char中[]，INT LIM）
    ^
/usr/include/stdio.h:449:9：注意：previous声明是在这里
ssiz​​e_t供函数getline（字符** __restrict，为size_t * __restrict，FILE * ...
        ^
产生3个错误。
 

解决方案

问题就是，你的系统中已经提供了一个名为功能函数getline 。 男人函数getline 应该告诉你它的签名。在我的系统是：

  ssize_t供函数getline（字符**限制linep，为size_t *限制linecapp，FILE *流限制）;
 

您可以匹配或只是重命名功能，被称为mygetline'或类似的东西。

另外，如果你能避免包括 stdio.h中，你能避免这个问题完全。

至于你的最后一个问题：

  

我应该通过什么选项锵编译K＆放时;被列入ř练习以免别的

您不能 - 系统头是它们是什么，并有因为K＆放presumably移动了; R是最后一次在1988年修订后的自那时以来，已经有多个C标准的更新。在某些方面，K＆安培; R为真正开始获得在牙齿长

I'm working through K&R, using Clang as my compiler.

Exercise 1-16 produces the "conflicting types for 'getline'" error when compiled with Clang. I'm guessing because one of the default libraries has a getline function.

What options should I pass to Clang when compiling K&R exercises so as to avoid anything else being included?

The exercise sample to be modified is:

#include <stdio.h>
#define MAXLINE 1000

int getline(char line[], int maxline);
void copy(char to[], char from[]);

/* print longest input line */
main()
{
  int len; /* current line length */
  int max; /* maximum line lenght seen so far */
  char line[MAXLINE]; /* current input line */
  char longest[MAXLINE]; /* longest line saved here */

  max = 0;

  while ((len = getline(line, MAXLINE)) > 0)
    if ( len > max) {
      max = len;
      copy(longest, line); /* line -> longest */
    }

  if (max > 0) /* there was a line */
    printf("\n\nLength: %d\nString: %s", max -1, longest);
  return 0;
}

/* getline: read a line into s, return length */
int getline(char s[], int lim)
{
  int c,i;

  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;
}

/* copy: copy "from" into "to"; assume to is big enough */
void copy(char to[], char from[])
{
  int i;

  i = 0;

  while((to[i] = from[i]) != '\0')
    ++i;
}

The errors from Clang when invoked as: cc ex1-16.c -o ex1-16

ex1-16.c:4:5: error: conflicting types for 'getline'
int getline(char line[], int maxline);
    ^
/usr/include/stdio.h:449:9: note: previous declaration is here
ssize_t getline(char ** __restrict, size_t * __restrict, FILE *...
        ^
ex1-16.c:17:38: error: too few arguments to function call, expected 3, have 2
  while ((len = getline(line, MAXLINE)) > 0)
                ~~~~~~~              ^
/usr/include/stdio.h:449:1: note: 'getline' declared here
ssize_t getline(char ** __restrict, size_t * __restrict, FILE *...
^
ex1-16.c:29:5: error: conflicting types for 'getline'
int getline(char s[], int lim)
    ^
/usr/include/stdio.h:449:9: note: previous declaration is here
ssize_t getline(char ** __restrict, size_t * __restrict, FILE *...
        ^
3 errors generated.

解决方案

The problem is just that your system already provides a function called getline. man getline should tell you its signature. On my system it's:

ssize_t getline(char ** restrict linep, size_t * restrict linecapp, FILE * restrict stream);

You can either match that or just rename your function to be called 'mygetline' or something like that.

Alternately, if you can avoid including stdio.h, you can avoid the problem entirely.

As to your final question:

What options should I pass to Clang when compiling K&R exercises so as to avoid anything else being included?

You can't - the system headers are what they are, and have presumably moved on since K&R was last revised in 1988. There have been multiple C standard updates since then. In some ways K&R is really starting to get long in the tooth.

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