C语言 fgetc() and fputc()用法及代码示例

fgetc()

fgetc()用于一次从文件单个字符获取输入。此函数返回该函数读取的字符数。它返回存在于文件指针指示的位置的字符。读取字符后，文件指针前进到下一个字符。如果指针位于文件末尾或发生错误，则此函数将返回EOF文件。
用法:

int fgetc(FILE *pointer)
pointer: pointer to a FILE object that identifies 
the stream on which the operation is to be performed.

// C program to illustate fgetc() function 
#include <stdio.h> 
  
int main () 
{ 
    // open the file 
    FILE *fp = fopen("test.txt","r"); 
  
    // Return if could not open file 
    if (fp == NULL) 
      return 0; 
  
    do
    { 
        // Taking input single character at a time 
        char c = fgetc(fp); 
  
        // Checking for end of file 
        if (feof(fp)) 
            break ; 
  
        printf("%c", c); 
    }  while(1); 
  
    fclose(fp); 
    return(0); 
}

输出：

The entire content of file is printed character by
character till end of file. It reads newline character
as well.

Using fputc()

fputc()用于一次将单个字符写入给定文件。它将给定字符写入文件指针指示的位置，然后前进文件指针。
该函数返回在成功执行写入操作的情况下写入的字符，否则在返回错误EOF的情况下返回。
用法:

int fputc(int char, FILE *pointer)
char: character to be written. 
This is passed as its int promotion.
pointer:pointer to a FILE object that identifies the 
stream where the character is to be written.

// C program to illustate fputc() function 
#include<stdio.h> 
int main() 
{ 
    int i = 0; 
    FILE *fp = fopen("output.txt","w"); 
  
    // Return if could not open file 
    if (fp == NULL) 
      return 0; 
  
    char string[] = "good bye", received_string[20]; 
  
    for (i = 0; string[i]!='\0'; i++) 
  
        // Input string into the file 
        // single character at a time 
        fputc(string[i], fp); 
  
    fclose(fp); 
    fp = fopen("output.txt","r"); 
  
    // Reading the string from file 
    fgets(received_string,20,fp); 
  
    printf("%s", received_string); 
  
    fclose(fp); 
    return 0; 
}

输出：

good bye

执行fputc()时，将字符串变量的字符一一写入文件中。当我们从文件中读取行时，我们得到与输入的相同的字符串。

注：本文由纯净天空筛选整理自 fgetc() and fputc() in C。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。