C語言 fgetc() and fputc()用法及代碼示例

fgetc()

fgetc()用於一次從文件單個字符獲取輸入。此函數返回該函數讀取的字符數。它返回存在於文件指針指示的位置的字符。讀取字符後，文件指針前進到下一個字符。如果指針位於文件末尾或發生錯誤，則此函數將返回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); 
}

輸出：

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

Using fputc()

fputc()用於一次將單個字符寫入給定文件。它將給定字符寫入文件指針指示的位置，然後前進文件指針。
該函數返回在成功執行寫入操作的情況下寫入的字符，否則在返回錯誤EOF的情況下返回。
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; 
}

輸出：

good bye

執行fputc()時，將字符串變量的字符一一寫入文件中。當我們從文件中讀取行時，我們得到與輸入的相同的字符串。

注：本文由純淨天空篩選整理自 fgetc() and fputc() in C。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。