pipe

问题 I want to read both stderr and stdout from a child process, but it doesn't work. main.rs use std::process::{Command, Stdio}; use std::io::{BufRead, BufReader}; fn main() { let mut child = Command::new("./1.sh") .stdout(Stdio::piped()) .stderr(Stdio::piped()) .spawn() .unwrap(); let out = BufReader::new(child.stdout.take().unwrap()); let err = BufReader::new(child.stderr.take().unwrap()); out.lines().for_each(|line| println!("out: {}", line.unwrap()) ); err.lines().for_each(|line| println!(

问题 I want to read both stderr and stdout from a child process, but it doesn't work. main.rs use std::process::{Command, Stdio}; use std::io::{BufRead, BufReader}; fn main() { let mut child = Command::new("./1.sh") .stdout(Stdio::piped()) .stderr(Stdio::piped()) .spawn() .unwrap(); let out = BufReader::new(child.stdout.take().unwrap()); let err = BufReader::new(child.stderr.take().unwrap()); out.lines().for_each(|line| println!("out: {}", line.unwrap()) ); err.lines().for_each(|line| println!(

问题 What is the design rationale that cat doesn't take list of file names from pipe input? Why did the designers choose that the following does not work? ls *.txt | cat Instead of this, they chose that we need to pass the file names as argument to cat as: ls *.txt | xargs cat 回答1: When you say ls *.txt | cat doesn't work, you should say that doesn't work as you expect. In fact, that works in the way it was thought to work. From man : cat - Concatenate FILE(s), or standard input, to standard

问题 What is the design rationale that cat doesn't take list of file names from pipe input? Why did the designers choose that the following does not work? ls *.txt | cat Instead of this, they chose that we need to pass the file names as argument to cat as: ls *.txt | xargs cat 回答1: When you say ls *.txt | cat doesn't work, you should say that doesn't work as you expect. In fact, that works in the way it was thought to work. From man : cat - Concatenate FILE(s), or standard input, to standard

问题 I would like to know not only user-side differences, but differences / common parts in Linux kernel implementation as well. 回答1: pipes are unidirectional, so you need two pipes to have bidirectional communication, whereas a socketpair is bidirectional. pipes are always stream-oriented, whereas socketpairs can be datagram-oriented. socketpairs are normal AF_UNIX sockets, which means that ancillary messages like SCM_RIGHTS and SCM_CREDENTIALS can be passed over them. In the kernel, pipes are

问题 I would like to know not only user-side differences, but differences / common parts in Linux kernel implementation as well. 回答1: pipes are unidirectional, so you need two pipes to have bidirectional communication, whereas a socketpair is bidirectional. pipes are always stream-oriented, whereas socketpairs can be datagram-oriented. socketpairs are normal AF_UNIX sockets, which means that ancillary messages like SCM_RIGHTS and SCM_CREDENTIALS can be passed over them. In the kernel, pipes are

问题 I would like to know not only user-side differences, but differences / common parts in Linux kernel implementation as well. 回答1: pipes are unidirectional, so you need two pipes to have bidirectional communication, whereas a socketpair is bidirectional. pipes are always stream-oriented, whereas socketpairs can be datagram-oriented. socketpairs are normal AF_UNIX sockets, which means that ancillary messages like SCM_RIGHTS and SCM_CREDENTIALS can be passed over them. In the kernel, pipes are

问题 I have to do the simulation of the command tee in C for Linux. How does tee work internally? It looks like a T-shaped pipe, so should I use a pipe? Is there a special kind of pipe? 回答1: tee takes stdin and copies the data stream to stdout as well as a file given as an option, it can be used in many very different situations. An implementation in C is quite simple, just make a program that copies all data from stdin to stdout, but also use the same output statements for stdout on a file that

问题 I have to do the simulation of the command tee in C for Linux. How does tee work internally? It looks like a T-shaped pipe, so should I use a pipe? Is there a special kind of pipe? 回答1: tee takes stdin and copies the data stream to stdout as well as a file given as an option, it can be used in many very different situations. An implementation in C is quite simple, just make a program that copies all data from stdin to stdout, but also use the same output statements for stdout on a file that

问题 I have to do the simulation of the command tee in C for Linux. How does tee work internally? It looks like a T-shaped pipe, so should I use a pipe? Is there a special kind of pipe? 回答1: tee takes stdin and copies the data stream to stdout as well as a file given as an option, it can be used in many very different situations. An implementation in C is quite simple, just make a program that copies all data from stdin to stdout, but also use the same output statements for stdout on a file that