pipe

问题 I know that this question is answered many times, but I still can't figure out how to do it. Maybe it's because I don't know the correct keyword to search for. Using echo -ne '\n' | enter doesn't work. My code is: #! /bin/bash #Grub-customizer sudo add-apt-repository ppa:danielrichter2007/grub-customizer echo -ne '\n' | return sudo apt-get update sudo apt-get install grub-customizer 回答1: You're supposed to pipe the \n into the command that's going to be receiving it (otherwise it won't ever

问题 I have a program that dumps pcap data gathered using the libpcap to stdout using pcap_dump function, with stdout as the FILE *. There is a little bit of cleanup necessary on SIGINT, so I handle that with sigaction(). This works nicely when executed from a shell. However, this program is intended to be called by another program, which doesn't seem to work. This "caller" program calls a pipe(), then a fork(), then the child's stdout file descriptor is closed, and replaced with the write end of

问题 I don't understand why Pipes are said unsafe when there are multiple senders and receivers. How the following code can be turned into code using Queues if this is the case ? Queues don't throw EOFError when closed, so my processes can't stop. Should I send endlessly 'Poison' messages to tell them to stop (this way, i'm sure all my processes receive at least one poison) ? I would like to keep the pipe p1 open until I decide otherwise (here it's when I have sent the 10 messages). from

问题 I want to delete all files which have names containing a specific word, e.g. "car". So far, I came up with this: find|grep car How do I pass the output to rm? 回答1: find . -name '*car*' -exec rm -f {} \; or pass the output of your pipeline to xargs : find | grep car | xargs rm -f Note that these are very blunt tools, and you are likely to remove files that you did not intend to remove. Also, no effort is made here to deal with files that contain characters such as whitespace (including

问题 I have the following code but obviously this is not real streaming. It is the best I could find but it reads the whole input file into memory first. I want to stream it to tarfile module without using all my memory when decrypting huge (>100Gb files) import tarfile, gnupg gpg = gnupg.GPG(gnupghome='C:/Users/niels/.gnupg') with open('103330-013.tar.gpg', 'r') as input_file: decrypted_data = gpg.decrypt(input_file.read(), passphrase='aaa') # decrypted_data.data contains the data decrypted

问题 I am writing a small code where i compare two times and find the difference and display it in HH:MM:SS format. library(magrittr) library(lubridate) s1 <- ymd_hms(Sys.time()) s2 <- ymd_hms(Sys.time()) +200 d1 <- seconds_to_period(as.numeric(difftime(s2, s1, units = "secs"))); d2 <-sprintf('%02d:%02d:%02d', hour(d1), minute(d1), second(d1)); d2 [1] "00:03:21" Another way i am trying is through piping techniques. But here, i am receiving an error. s1 <- ymd_hms(Sys.time()) s2 <- ymd_hms(Sys.time

问题 Here is the screenshot of error: Here is the code of DTO: import {IsString, IsInt,IsEmail,IsNotEmpty, IsNumberString, IsIn} from 'class-validator' export class logindto{ @IsEmail() username:String @IsNotEmpty() password:String } Here is the code of controller: @Post('login') log(@Body('username')username:logindto,@Body('password')password:logindto):any{ return this.crudservice.loginsys(username,password) } Here is the code of services: export class CrudService { constructor(@InjectModel(

问题 I have one named pipe (FIFO) say : 'MY_FIFO' One process reads the fifo from multiple processes to get instructions. (1) reader bash script: while read LINE < 'MY_FIFO' do # process line done (many) writer bash script: while [ 1 ] do INSTRUCTION = # get an instruction echo $INSTRUCTION > 'MY_FIFO' done This works fine to pass instructions to the reader when we have 1 writer or that the writers don't write at the same time. But if we have many writers writing at the same time, the reader gets

问题 I'm working on a sample program to learn how pipes and forking works. In my very basic implementation, in my child process, i closed 0 and duplicated the read end of the pipe so that file descriptor 0 is now the read end of my pipe. From my parent process, I write out a string, and in my child process, I read the string using cin as cin essentially is my read end of the pipe and what I observe is the complete string does not print out and I can't seem to understand why! #include <iostream>

问题 I'm working on a sample program to learn how pipes and forking works. In my very basic implementation, in my child process, i closed 0 and duplicated the read end of the pipe so that file descriptor 0 is now the read end of my pipe. From my parent process, I write out a string, and in my child process, I read the string using cin as cin essentially is my read end of the pipe and what I observe is the complete string does not print out and I can't seem to understand why! #include <iostream>