stdin

问题 Let's say I have a C/C++ file named userfile.c . Using Python, how can I invoke the local gcc compiler so that the file is compiled and an executable is made? More specifically, I would like to provide some input (stdin) via some file input.txt and I want to save the standard output into another file called output.txt . I saw some documentation that I will need to use subprocess, but I'm not sure how to call that and how to provide custom input. 回答1: A simple solution will be as given below:

问题 I'm currently programming a simple timer, which runs from 00s to 55s and then start from 00 again and keeps counting until the user stops it. For that purpose I made two options for the user: 1. start & 2. reset. Choosing number one runs the program, and choosing number two, as I its supposed, will turn the timer in to 00s and keep it there. Now the problem I'm facing is that I want to get an input from the user without stopping the timer (i.e. enabling the user to enter 2 at anytime while

问题 How exactly does Python receive echo input | python script and python script input differently? I know that one comes through stdin and the other is passed as an argument, but what happens differently in the back-end? 回答1: I'm not exactly sure what is confusing you here. stdin and command line arguments are treated as two different things. The command line args are passed automatically in the argv parameter as with any other c program. The main function for Python that is written in C (that

问题 I have a problem concerning the reading of the stdout in python. I have to explain a bit what I am trying to do. I have a Python program ( foo ); this calls a second python program ( bar ). bar will give back to stdout status details and other information to be logged. The foo now has to read this. In principle it works. I can grab the output of bar and send it to a log file without any problems. The problems start when I try to look for certain phrases in the output from bar (the status

问题 If I want to receive a one character input in C, how would I check to see if extra characters were sent, and if so, how would I clear that? Is there a function which acts like getc(stdin), but which doesn't prompt the user to enter a character, so I can just put while(getc(stdin)!=EOF); ? Or a function to peek at the next character in the buffer, and if it doesn't return NULL (or whatever would be there), I could call a(nother) function which flushes stdin? Edit So right now, scanf seems to

问题 How would I respond to a command line prompt programmatically with node.js? For example, if I do process.stdin.write('sudo ls'); The command line will prompt for a password. Is there an event for 'prompt?' Also, how do I know when something like process.stdin.write('npm install') is complete? I'd like to use this to make file edits (needed to stage my app), deploy to my server, and reverse those file edits (needed for eventually deploying to production). Any help would rock! 回答1: You'll want

问题 I have an application that implements an interactive shell, similar to how the Python console / irb works. The problem now is that if the user accidentally hits ^D EOF is issued and my getline() call returns an empty string which i treat as "no input" and display the prompt again. This then results in an endless loop that prints the prompt. Now in Python I would solve that problem by catching EOFError , but in C++ no exception is raised I could catch and there doesn't seem to be a setting on

问题 I have a method that creates a subprocess and connects it STDIN to an anonymous pipe; which is not working. Its not raising any exceptions, the subprocess just never seems to never read the data. (the subprocess is the 'zenity' executable for displaying a progress bar in the GUI) class Screen(object): def __init__(self, display = ":0", bin = '/usr/bin/zenity'): self.bin = bin os.environ['DISPLAY'] = display self.dis = display def displayProgress(self, text, pulse = True, title = 'Progess'): '

问题 I'm trying to understand process.stdin. For example - I need to show array elements in console. And i should allow user choose which element will be shown. I have code: var arr = ['elem1','elem2','elem3','elem4','elem5'], lastIndx = arr.length-1; showArrElem(); function showArrElem () { console.log('press number from 0 to ' + lastIndx +', or "q" to quit'); process.stdin.on('readable', function (key) { var key = process.stdin.read(); if (!process.stdin.isRaw) { process.stdin.setRawMode( true )

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 6 years ago . public class New { public static void main(String[] args) { System.out.println("Calculator"); float a = StdIn.readFloat(); char sign = StdIn.readChar(); float b = StdIn.readFloat(); float c = 0; if (sign == '+') c = a+b; else if (sign == '-') c = a-b; else if (sign == 'x') c = a*b; else if (sign ==