If you want to redirect the output of one program into the input of another, just use a simple pipeline: program1 arg arg | program2 arg arg If you want to save the output of program1 into a file and pipe it into program2, you can use tee(1): program1 arg arg | tee output-file | … Read more
Use a subprocess.PIPE, as explained in the subprocess docs section “Replacing shell pipeline”: import subprocess p1 = subprocess.Popen([“cat”, “file.log”], stdout=subprocess.PIPE) p2 = subprocess.Popen([“tail”, “-1”], stdin=p1.stdout, stdout=subprocess.PIPE) p1.stdout.close() # Allow p1 to receive a SIGPIPE if p2 exits. output,err = p2.communicate() Or, using the sh module, piping becomes composition of functions: import sh output = sh.tail(sh.cat(‘file.log’), … Read more
Without async/await, it’s quite nasty. With async/await, just do this: Promise.all(promises).then(async (responses) => { for (…) { await new Promise(resolve => stream.on(“finish”, resolve)); //extract the text out of the PDF } })
Use bindings to innerHTML or outerHTML to render already escaped html. For example <span [innerHTML]=”someString | toHtmlPipe”></span>. See this plunk: @Pipe({ name: ‘wrapBold’ }) class WrapBold { transform(content) { return `<b>${content}</b>`; } } @Component({ selector: ‘my-app’, pipes: [WrapBold], template: ` <div> Hello <span [outerHTML]=”content | wrapBold”></span> </div> ` }) export class App { constructor() { … Read more
Even after the first command of your pipeline exits (and thust closes stdout=~fdPipe[1]), the parent still has fdPipe[1] open. Thus, the second command of the pipeline has a stdin=~fdPipe[0] that never gets an EOF, because the other endpoint of the pipe is still open. You need to create a new pipe(fdPipe) for each |, and … Read more
By using $() you are (effectively) creating a subshell. Thus the PIPESTATUS instance you need to look at is only available inside your subshell (i.e. inside the $()), since environment variables do not propagate from child to parent processes. You could do something like this: OUT=$( wget -q “http://budueba.com/net” | tee -a “file.txt”; exit ${PIPESTATUS[0]} … Read more
There is no way to do that using a default pipe. Here is the list of supported pipes by default: https://github.com/angular/angular/blob/master/modules/angular2/src/common/pipes/common_pipes.ts. That said you can easily add a pipe for such use case: import {Injectable, Pipe} from ‘angular2/core’; @Pipe({ name: ‘myfilter’ }) @Injectable() export class MyFilterPipe implements PipeTransform { transform(items: any[], args: any[]): any { … Read more
QProcess executes one single process. What you are trying to do is executing a shell command, not a process. The piping of commands is a feature of your shell. There are three possible solutions: Put the command you want to be executed as an argument to sh after -c (“command”): QProcess sh; sh.start(“sh”, QStringList() << … Read more
unbuffer, part of expect (sudo apt-get install expect-dev on Ubuntu Lucid), can fool a program into thinking it’s connected to a TTY. $ tty /dev/pts/3 $ echo | tty not a tty $ echo | unbuffer tty /dev/pts/11
One of the best examples of a practical use of a named pipe… From http://en.wikipedia.org/wiki/Netcat: Another useful behavior is using netcat as a proxy. Both ports and hosts can be redirected. Look at this example: nc -l 12345 | nc www.google.com 80 Port 12345 represents the request. This starts a nc server on port 12345 … Read more