C++/Php/Python/Shell 程序按行读取文件或者控制台的实现

#include<stdio.h>#include<string.h>int main(){  const char* in_file = "input_file_name";  const char* out_file = "output_file_name";  FILE *p_in = fopen(in_file, "r");  if(!p_in){    printf("open file %s failed!!!", in_file);    return -1;  }      FILE *p_out = fopen(out_file, "w");  if(!p_in){    printf("open file %s failed!!!", out_file);    if(!p_in){      fclose(p_in);    }    return -1;  }  char buf[2048];  //按行读取文件内容  while(fgets(buf, sizeof(buf), p_in) != NULL) {    //写入到文件    fwrite(buf, sizeof(char), strlen(buf), p_out);  }  fclose(p_in);  fclose(p_out);  return 0;}

#include<stdio.h>int main(){  char buf[2048];  gets(buf);  printf("%s/n", buf);  return 0;}/// scanf 遇到空格等字符会结束/// gets 遇到换行符结束

<?php$filename = "input_file_name";$fp = fopen($filename, "r");if(!$fp){  echo "open file $filename failed/n";  exit(1);}else{  while(!feof($fp)){    //fgets(file,length) 不指定长度默认为1024字节    $buf = fgets($fp);    $buf = trim($buf);    if(empty($buf)){      continue;    }    else{      echo $buf."/n";    }  }  fclose($fp);}?>

<?php$fp = fopen("/dev/stdin", "r");while($input = fgets($fp, 10000)){    $input = trim($input);    echo $input."/n";}fclose($fp);?>

#coding=utf-8# 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。# 编码申明，写在第一行就好 import sysinput = sys.stdinfor i in input:  #i表示当前的输入行  i = i.strip()  print iinput.close()

#!/bin/bash#读取文件, 则直接使用文件名; 读取控制台, 则使用/dev/stdinwhile read linedo  echo ${line}done < filename

#!/bin/bashwhile read linedo  echo ${line}done < /dev/stdin