撰写过程的输出缓冲器

Question

可能重复：
How to execute a command and get output of command within C++?

在我的C++程序，我正在使用execv /系统的外部程序。

我想程序的一个缓冲区输出重定向在我的程序，即：

char* buff[some size large enough for any possible output]; 
system(some program); 
//THE PROGRAM I JUST RAN IS A SPECIAL BLACK BOX PROGRAM THAT RUNS 
//AND PARSE AN HTTP DUMP FILE AND PRINTS IT TO THE SCREEN WHEN RUNNING 
//I WANT THE OUTPUT TO GO A BUFFER IN MY PROGRAM. 
//THE IDEA IS TO HAVE THE DATA OF THE OUTPUT ON THE BUFFER RATHER THAN ON A FILE 

//have the buffer filled with the output of the program 

感谢:-)

Answer 1

我不知道是否有一些其他的方式做这个，但这是我想到的

char* buff[some size large enough for any possible output]; 
system(some program >somefile.txt); 

//have the buffer filled with the output of the program 
// And redirect it into a file 


//Do initial validity checks and open the file 



read(somefile.txt,buff,bufflen); 
//Read the file 

unlink somefile.txt 
//Unlink if the file is not needed 

用你想从文件中读取的字节数替换bufflen。

Answer 2

如果你想读取一个子进程的输出（至少在POSIX/UNIX/Linux世界中），你应该真的在考虑使用管道进行进程间通信。一个有用的问题/ Stackoverflow上的一些很好的资源链接的答案在这里：fork(), pipe() and exec() process creation and communication