stderr

问题 I want to execute an external command from within my Perl script, putting the output of both stdout and stderr into a $variable of my choice, and to get the command\'s exit code into the $? variable. I went through solutions in perlfaq8 and their forums, but they\'re not working for me. The strange thing is that I don\'t get the output of sdterr in any case, as long as the exit code is correct. I\'m using Perl version 5.8.8, on Red Hat Linux 5. Here\'s an example of what I\'m trying: my $cmd=

问题 I would like to log all the output of a Python script. I tried: import sys log = [] class writer(object): def write(self, data): log.append(data) sys.stdout = writer() sys.stderr = writer() Now, if I \"print \'something\' \" it gets logged. But if I make for instance some syntax error, say \"print \'something# \", it wont get logged - it will go into the console instead. How do I capture also the errors from Python interpreter? I saw a possible solution here: http://www.velocityreviews.com

问题 Is it possible to redirect stdout from an external program to a variable and stderr from external programs to another variable in one run? For example: $global:ERRORS = @(); $global:PROGERR = @(); function test() { # Can we redirect errors to $PROGERR here, leaving stdout for $OUTPUT? $OUTPUT = (& myprogram.exe \'argv[0]\', \'argv[1]\'); if ( $OUTPUT | select-string -Pattern \"foo\" ) { # do stuff } else { $global:ERRORS += \"test(): oh noes! \'foo\' missing!\"; } } test; if ( @($global

问题 I\'m playing with i/o shell redirection. The commands I\'ve tried (in bash): ls -al *.xyz 2>&1 1> files.lst and ls -al *.xyz 1> files.lst 2>&1 There is no any *.xyz file in current folder. These commands gives me the different results. The first command shows an error message ls: *.xyz: No such file or directory on the screen. But the second one prints this error message to the file. Why did the first command failed to write an err output to the file? 回答1: This error: ls: *.xyz: No such file

问题 I\'d like to temporarily redirect stderr in a Ruby script for the duration of a block, ensuring that I reset it to its original value at the end of the block. I had trouble finding how to do this in the ruby docs. 回答1: In Ruby, $stderr refers to the output stream that is currently used as stderr, whereas STDERR is the default stderr stream. It is easy to temporarily assign a different output stream to $stderr . require "stringio" def capture_stderr # The output stream must be an IO-like

问题 I\'ve written a Windows service in C# using the ServiceBase helper. During its execution some procedures on an external native DLL are called. Annoyingly, those procedures write to stdout and/or stderr in a uncontrolled manner as no sources are given for this DLL. Is it possible to redirect those outputs from the C# service to a log file? 回答1: You can do this via PInvoke to SetStdHandle: [DllImport("Kernel32.dll", SetLastError = true) ] public static extern int SetStdHandle(int device, IntPtr

问题 I have an application that logs a lot of noise to stderr and REALLY slows down the execution of the application. I would like to redirect that output to null. Is this possible with cmd.exe? 回答1: Your DOS command 2> nul Read page Using command redirection operators . Besides the "2>" construct mentioned by Tanuki Software, it lists some other useful combinations. 来源： https://stackoverflow.com/questions/4507312/how-to-redirect-stderr-to-null-in-cmd-exe

问题 This question already has answers here : Bash script - store stderr in a variable [duplicate] (4 answers) Closed 3 years ago . Bash how do you capture stderr to a variable? I would like to do something like this inside of my bash script sh -c path/myExcecutable-bin 2>&1 =MYVARIABLE How do you send stderror output to a variable ? 回答1: To save both stdout and stderr to a variable: MYVARIABLE="$(path/myExcecutable-bin 2>&1)" Note that this interleaves stdout and stderr into the same variable. To

问题 I have a python subprocess that I\'m trying to read output and error streams from. Currently I have it working, but I\'m only able to read from stderr after I\'ve finished reading from stdout . Here\'s what it looks like: process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE) stdout_iterator = iter(process.stdout.readline, b\"\") stderr_iterator = iter(process.stderr.readline, b\"\") for line in stdout_iterator: # Do stuff with line print line for line in stderr

问题 I want to get the stdout in a variable after running the os.system call. Lets take this line as an example: batcmd=\"dir\" result = os.system(batcmd) result will contain the error code ( stderr 0 under Windows or 1 under some linux for the above example). How can I get the stdout for the above command without using redirection in the executed command? 回答1: If all you need is the stdout output, then take a look at subprocess.check_output(): import subprocess batcmd="dir" result = subprocess