我需要创建一个程序，将硬编码输入列入不同的文件。我在fprintf部分遇到过问题。
完整的程序列在后面。
我和老师谈过，她标记了
else
{
print_rmchr(str1, chr1);
print_rmchr(str2, chr2);
print_rmchr(str3, chr3);
print_rmchr(str4, chr4);
print_rmchr(str5, chr5);
if (fclose(filePtr) != 0)
printf("Unable to close the data file.\n");
}
和
if (fprintf("The string '%s' will be removed from '%c' characters. \n\n", str, ch) < 0)
printf("Unable to print non-modified string with a modifying character. \n");
rmchr(str, ch);
if (fprintf("New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");
作为我的作业中代码的错误部分。
我在starkoverflow上查看了类似的问题，发现我必须在fprintf之前放置filepointer。 我的第二块坏代码现在看起来像这样：
if (fprintf(filePtr, "The string '%s' will be removed from '%c' characters. \n\n", str, ch) < 0)
printf("Unable to print non-modified string with a modifying character. \n");
rmchr(str, ch);
if (fprintf(filePtr, "New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");
然后编译器对我大吼大叫，因为不知道为什么有文件指针，所以我也把它修复为
print_rmchr(filePtr, str, chr);
然后它开始对我大喊大叫，好像＆＃34;从不兼容的指针类型传递参数＆＃34;。它看起来适合我，但缺少某些东西（？）我想。
我的完整计划：
/*
* A simple program to remove certain characters from the given strings
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main () {
// print array before and after editing array
void print_rmchr (char str[], char ch);
char str1[20] = "abracadabra"; //string #1
char str2[20] = "abracadabra"; //string #2
char str3[20] = "abracadabra"; //string #3
char str4[20] = "aaaa"; //string #4
char str5[20] = "aaaa"; //string #5
char chr1 = 'a'; //character #1
char chr2 = 'b'; //character #2
char chr3 = 'n'; //character #3
char chr4 = 'a'; //character #4
char chr5 = 'n'; //character #5
FILE *filePtr;
filePtr = fopen("rmchr.out", "w");
if( filePtr == NULL)
printf("Unable to open the data file.\n");
else
{
print_rmchr(filePtr, str1, chr1);
print_rmchr(filePtr, str2, chr2);
print_rmchr(filePtr, str3, chr3);
print_rmchr(filePtr, str4, chr4);
print_rmchr(filePtr, str5, chr5);
if (fclose(filePtr) != 0)
printf("Unable to close the data file.\n");
}
return 0;
}
//remove certain characters from array
void rmchr(char str[], char ch) {
int i, j = 0; //loop variable
int size; //lengh
char new_str[20]; //new array
size = strlen(str);
for (i = 0; i < size; i++) {
if (str[i] != ch) {
new_str[j] = str[i];
j++;
}
}
new_str[j] = '\0';
strcpy(str, new_str);
}
// print array before and after editing array
void print_rmchr (char str[], char ch){
//remove certain characters from array
void rmchr(char str[], char ch);
if (fprintf(filePtr, "The string '%s' will be removed from '%c' characters. \n\n", str, ch) < 0)
printf("Unable to print non-modified string with a modifying character. \n");
rmchr(str, ch);
if (fprintf(filePtr, "New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");
}
/* In case you will need user input:
//USER INPUT
printf("Enter the string : \n");
gets(str);
printf("Enter character which you want to delete : \n");
scanf("%ch", &ch);
print_rmchr(str, ch);
*/
最终，更正版本：
/*
* A simple program to remove certain characters from the given strings
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 20
int main () {
// print array before and after editing array
void print_rmchr (FILE *filePtr, char str[], char ch);
char str1[MAX] = "abracadabra"; //string #1
char str2[MAX] = "abracadabra"; //string #2
char str3[MAX] = "abracadabra"; //string #3
char str4[MAX] = "aaaa"; //string #4
char str5[MAX] = "aaaa"; //string #5
char chr1 = 'a'; //character #1
char chr2 = 'b'; //character #2
char chr3 = 'n'; //character #3
char chr4 = 'a'; //character #4
char chr5 = 'n'; //character #5
FILE *filePtr = NULL; // best to always initialize stack variables
if( NULL == (filePtr = fopen("rmchr.txt", "w") ) )
{
// output your message, plus the system error message
perror("fopen rmchr.out for write failed");
// exit() and EXIT_FAILURE in 'stdlib.h'
exit(EXIT_FAILURE);
}
// implied else, fopen successful
print_rmchr(filePtr, str1, chr1);
print_rmchr(filePtr, str2, chr2);
print_rmchr(filePtr, str3, chr3);
print_rmchr(filePtr, str4, chr4);
print_rmchr(filePtr, str5, chr5);
if (fclose(filePtr) != 0)
printf("Unable to close the data file.\n");
return 0;
}
//remove certain characters from array
void rmchr(char str[], char ch)
{
size_t i; //loop variable
int j = 0; //loop variable
char new_str[MAX]; //new array
for (i = 0; str[i]; i++) {
if (str[i] != ch) {
new_str[j] = str[i];
j++;
}
}
new_str[j] = '\0';
strcpy(str, new_str);
}
// print array before and after editing array
print_rmchr (FILE *filePtr, char str[], char ch){
//remove certain characters from array
void rmchr(char str[], char ch);
if (fprintf(filePtr, "All instances of character %c will be removed from string '%s. \n\n", ch, str) < 0)
printf("Unable to print non-modified string with a modifying character. \n");
rmchr(str, ch);
if (fprintf(filePtr, "New modified string is: '%s'. \n\n", str) < 0)
printf("Unable to print new modified string. \n");
}
/* In case you will need user input:
//USER INPUT
printf("Enter the string : \n");
fgets(str);
printf("Enter character which you want to delete : \n");
scanf("%ch", &ch);
//need to check the returned value of scanf
print_rmchr(str, ch);
*/
答案 0 :(得分：1)
如果要将更多或其他参数传递给函数，则必须同时修改调用和函数定义，以使它们彼此兼容。从
改变它void print_rmchr (char str[], char ch);
为：
void print_rmchr (FILE *filePtr, char str[], char ch);
按原样，符号filePtr是main的本地符号，print_rmchr中未知。
答案 1 :(得分：0)
应用所有注释后，rmchr()函数变为：
//remove certain characters from array
void rmchr(char str[], char ch)
{
size_t i;
int j = 0; //loop variable
for (i = 0; str[i]; i++)
{
if (str[i] != ch)
{
new_str[j] = str[i];
j++;
}
}
str[j] = '\0';
}
打开文件时，此模式会给您带来问题，主要是因为以下代码的完全缩进：
FILE *filePtr;
filePtr = fopen("rmchr.out", "w");
if( filePtr == NULL)
printf("Unable to open the data file.\n");
else
suggest using the following pattern:
FILE *filePtr = NULL; // best to always initialize stack variables
if( NULL == (filePtr = fopen("rmchr.out", "w") ) )
{
// output your message, plus the system error message
perror( "fopen rmchr.out for write failed" );
// exit() and EXIT_FAILURE in 'stdlib.h'
exit( EXIT_FAILURE );
}
// implied else, fopen successful