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问题 In Python I'm using sys.stdout = None before some calls that I don't control. These calls may call some subprocesses that write to stdout. How can I avoid this subprocesses calls to write to stdout? Again, I don't have ownership of the code that calls the subprocess. It seems subprocess.Popen (and similar) doesn't honor sys.stdout. 回答1: You could replace subprocess.Popen with a custom function that suppresses stdout and stderr : import subprocess import inspect def Popen(*args, **kwargs): sig

问题 In Python you can print on the same line using \r to move back to the start of the line. This works well for progress bars or increasing precentage counters, eg: Python print on same line However when printing lines that may decrease in length, this leaves the previous lines text there, eg: import sys for t in ['long line', '%']: sys.stdout.write(t + '\r') sys.stdout.write('\n') Leaves the terminal text as: %ong line . Whats the best way to write a shorter line after a longer one, when

问题 I would like to set up a variable in my code that would ultimately define if I'll see some output or not. "hello" writes to stdout "hello" > $null supresses output My idea is something like this: $debugOutputSwitch = $true $outputVar = $null if ($debugOutputSwitch){ $outputVar = **STDOUT** } ... Write-Host "Something I want out anyway" "Something I might not want on STDOUT" > $outputVar If this general idea is a way to go, then STDOUT is what I'm looking for If this idea is completely wrong..

问题 I am currently calling ffmpeg to extract a binary data stream from a video file, and then putting that binary data into a list. There is a lot of data in this data stream, about 4,000 kb. Here is the code # write and call ffmpeg command, piping stdout cmd = "ffmpeg -i video.mpg -map 0:1 -c copy -f data -" proc = subprocess.Popen(cmd, stdout=subprocess.PIPE) # read from stdout, byte by byte li = [] for char in iter(lambda: proc.stdout.read(1), ""): li.append(char) This works fine. However, if

问题 Using FFmpeg I converted a video (mpeg2) into jpgs, redirecting the output into the standard output. StringBuilder str = new StringBuilder(); //Input file path str.Append(string.Format(" -i {0}", myinputFile)); //Set the frame rate str.Append(string.Format(" -r {0}", myframeRate); //Indicate the output format str.Append(" -f image2pipe"); //Connect the output to the standard output str.Append(" pipe:1"); return str.ToString(); I'm able to receive the callback from the process with the data:

问题 I am running a build, and I would like to be able to view the progress as it happens. But I would also like to save the output if the build has an error. I know I can use Process.UseShellExecute = false , and RedirectStandardOutput , but that's only part of the story. How can I do this? 回答1: Update As Greg mentions in the comments below, MSBuild can write out to a log file while also outputting to console out of the box. MSBuild [options] /filelogger /fileloggerparameters:LogFile=MSBuildLog

问题 I'm not in the programming area but I recently got interested in Python. I was writing some functions but for debugging I need to see what commands are running. For instance: def foo(): for i in xrange(0,5): a = 1 + i Is it possible to make the interpreter output >>> for i in xrange(0,5) >>> a = 1 + 0 >>> a = 1 + 1 >>> a = 1 + 2 >>> a = 1 + 3 >>> a = 1 + 4 For >>> foo() Or at least write to a file what is happening? I did some scripting in the past and I remember that this was possible in DOS

问题 I'm currently the Teaching Assistant for an Introduction to C class. The class is being taught using Visual Studio, but when grading I just use a simple Windows batch script to process all the assignment submissions, compile them, run them on a test file, and redirect the output to a series of text files I can print out, mark up, and hand back to students. The whole process works very well, except for the fact that when I redirect stdin, it does not appear in the redirected stdout the same

问题 This question already has answers here : JUnit testing with simulated user input (7 answers) Closed 4 years ago . I want to do some tests on my P2P system by using some input like: "join 8". 8 is the Node number. For my system, the command "join 8" is read from stdin, but I don't want to type it hundred times for hundred tests, so I write a test function to randomly generate node numbers and then call the "join" command by itself. So I want JAVA to write commands instead of my own input to

问题 i have a function called foo which is listening to the stdout, what i want is to return some string which i got from stdout. here is my function; dynamic foo(process) { return ( process.stdout.transform(UTF8.decoder).listen((data) { String s = data.toString(); // print(s); if (s.contains("received event of")) { var s1 = s.split(":"); print("${s1[1]}"); return s1[1]; } })); } I want to return s1 to the calling function 回答1: This should do what you want Future<String> dynamic foo(process) {