Possible Duplicate:
Learning C by K&R, error when trying to compile programs from book with arrays and function calls以前的“功能”的声明,在这里用C
虽然学习由Brian W. Kernighan和丹尼斯·里奇M. C程序设计语言,我想在第1.9字符数组的例子。下面是代码:
/* read a set of text lines and print the longest */
#include <stdio.h>
#define MAXLINE 1000 /* maximum input line length */
/* declare functions: getline() and copy() */
int getline(char line[], int maxline);
void copy(char to[], char from[]);
/* getline: read a line into array "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'; /* the null character whose value is 0 */
return i;
}
/* copy: copy 'from' into 'to'; assume to is big enough */
/* the return type of copy is "void" -- no value is returned */
void copy(char to[], char from[])
{
int i;
i = 0;
while ((to[i] = from[i]) != '\0') /* terminated with a \0 */
++i;
}
/* print the longest input line */
int main()
{
int len; /* current line length */
int max; /* maximum length 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);
}
if (max>0) /* there was a line */
printf("%s", longest);
return 0;
}
主要有两种错误:
- 错误:冲突的类型为 '函数getline'
- 错误:的 '函数getline' 先前的声明是在这里
完整的错误列表在这里:
/Users/C/Codes/Ritchie/array_char.c:8: error: conflicting types for ‘getline’
/usr/include/stdio.h:449: error: previous declaration of ‘getline’ was here
/Users/C/Codes/Ritchie/array_char.c:13: error: conflicting types for ‘getline’
/usr/include/stdio.h:449: error: previous declaration of ‘getline’ was here
/Users/C/Codes/Ritchie/array_char.c: In function ‘getline’:
/Users//C/Codes/Ritchie/array_char.c:17: warning: comparison between pointer and integer
/Users/C/Codes/Ritchie/array_char.c:17: warning: comparison with string literal results in unspecified behavior
我不确定出了什么问题,因为它与本书中的代码完全相同。也许功能在开头的声明:
int getline(char line[], int maxline);
void copy(char to[], char from[]);
有问题吗?谢谢!
请发布实际的错误消息(不要释义) – CrazyCasta
是否有理由在这里完成所有困难的方式,或者您可以使用'fgets'和'strcpy'来代替? –