C++/Php/Python/Shell 程序按行读取文件或者控制台详解编程语言

 1 #include<stdio.h> 
 2 #include<string.h> 
 3  
 4 int main(){ 
 5     const char* in_file = "input_file_name"; 
 6     const char* out_file = "output_file_name"; 
 7  
 8     FILE *p_in = fopen(in_file, "r"); 
 9     if(!p_in){ 
10         printf("open file %s failed!!!", in_file); 
11         return -1; 
12     } 
13          
14     FILE *p_out = fopen(out_file, "w"); 
15     if(!p_in){ 
16         printf("open file %s failed!!!", out_file); 
17         if(!p_in){ 
18             fclose(p_in); 
19         } 
20         return -1; 
21     } 
22  
23     char buf[2048]; 
24     //按行读取文件内容 
25     while(fgets(buf, sizeof(buf), p_in) != NULL) { 
26         //写入到文件 
27         fwrite(buf, sizeof(char), strlen(buf), p_out); 
28     } 
29  
30     fclose(p_in); 
31     fclose(p_out); 
32     return 0; 
33 }

 1 #include<stdio.h> 
 2  
 3 int main(){ 
 4     char buf[2048]; 
 5  
 6     gets(buf); 
 7     printf("%s/n", buf); 
 8  
 9     return 0; 
10 } 
11  
12 /// scanf 遇到空格等字符会结束 
13 /// gets 遇到换行符结束

 1 <?php 
 2 $filename = "input_file_name"; 
 3  
 4 $fp = fopen($filename, "r"); 
 5 if(!$fp){ 
 6     echo "open file $filename failed/n"; 
 7     exit(1); 
 8 } 
 9 else{ 
10     while(!feof($fp)){ 
11         //fgets(file,length) 不指定长度默认为1024字节 
12         $buf = fgets($fp); 
13  
14         $buf = trim($buf); 
15         if(empty($buf)){ 
16             continue; 
17         } 
18         else{ 
19             echo $buf."/n"; 
20         } 
21     } 
22     fclose($fp); 
23 } 
24 ?>

 1 <?php 
 2 $fp = fopen("/dev/stdin", "r"); 
 3  
 4 while($input = fgets($fp, 10000)){ 
 5         $input = trim($input); 
 6        echo $input."/n"; 
 7 } 
 8  
 9 fclose($fp); 
10 ?>

1 file = open("read.py", "r") 
2 while 1: 
3     line = file.readline() 
4     if not line: 
5         break 
6     #line = line 
7     line = line.strip() ##移除字符串头尾指定的字符（默认为空格） 
8     print line

 1 #coding=utf-8 
 2  
 3 # 如果要在python2的py文件里面写中文，则必须要添加一行声明文件编码的注释，否则python2会默认使用ASCII编码。 
 4 # 编码申明，写在第一行就好  
 5 import sys 
 6  
 7 input = sys.stdin 
 8  
 9 for i in input: 
10     #i表示当前的输入行 
11  
12     i = i.strip() 
13     print i 
14  
15 input.close()

1 #!/bin/bash 
2  
3 #读取文件, 则直接使用文件名; 读取控制台, 则使用/dev/stdin 
4  
5 while read line 
6 do 
7     echo ${line} 
8 done < filename

1 #!/bin/bash 
2  
3 while read line 
4 do 
5     echo ${line} 
6 done < /dev/stdin