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Questions tagged [stdout]

The standard output stream (stdout) is the stream where a program writes its output data.

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catching stdout in realtime from subprocess

I want to subprocess.Popen() rsync.exe in Windows, and print the stdout in Python. My code works, but it doesn't catch the progress until a file transfer is done! I want to print the progress for each file in real time. Using Python 3.1 now since I…
John A
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Difference between $stdout and STDOUT in Ruby

In Ruby, what is the difference between $stdout (preceded by a dollar sign) and STDOUT (in all caps)? When doing output redirection, which should be used and why? The same goes for $stderr and STDERR. Edit: Just found a related question.
jrdioko
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How to get Rails.logger printing to the console/stdout when running rspec?

Same as title: How to get Rails.logger printing to the console/stdout when running rspec? Eg. Rails.logger.info "I WANT this to go to console/stdout when rspec is running" puts "Like how the puts function works" I still want Rails.logger to go to…
s12chung
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How to make output of any shell command unbuffered?

Is there a way to run shell commands without output buffering? For example, hexdump file | ./my_script will only pass input from hexdump to my_script in buffered chunks, not line by line. Actually I want to know a general solution how to make any…
bodacydo
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Continuously read from STDOUT of external process in Ruby

I want to run blender from the command line through a ruby script, which will then process the output given by blender line by line to update a progress bar in a GUI. It's not really important that blender is the external process whose stdout I need…
ehsanul
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How do file descriptors work?

Can someone tell me why this does not work? I'm playing around with file descriptors, but feel a little lost. #!/bin/bash echo "This" echo "is" >&2 echo "a" >&3 echo "test." >&4 The first three lines run fine, but the last two error out. Why?
Trcx
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How do I check if stdin has some data?

In Python, how do you check if sys.stdin has data or not? I found that os.isatty(0) can not only check if stdin is connected to a TTY device, but also if there is data available. But if someone uses code such as sys.stdin =…
mlzboy
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How to replicate tee behavior in Python when using subprocess?

I'm looking for a Python solution that will allow me to save the output of a command in a file without hiding it from the console. FYI: I'm asking about tee (as the Unix command line utility) and not the function with the same name from Python…
sorin
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10 answers

How to redirect stdout and stderr to logger in Python

I have a logger that has a RotatingFileHandler. I want to redirect all Stdout and Stderr to the logger. How to do so?
orenma
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How to write CSV output to stdout?

I know I can write a CSV file with something like: with open('some.csv', 'w', newline='') as f: How would I instead write that output to stdout?
jsf80238
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Gradle: How to get output from test STDERR/STDOUT into console?

(Gradle 3.2.1) I run some java tests, which logs output in Stderr/Stdout. I can see that output, if I start gradle test --info but in that case, much of unwanted output from 3-rd party libraries is there too. Documentation suggests using…
Alexei Vinogradov
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Redirect console output to string in Java

I have one method whose return type is void and it prints directly on console. However I need that output in a String so that I can work on it. As I can't make any changes to the method with return type void I have to redirect that output to a…
SRK
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How to set sys.stdout encoding in Python 3?

Setting the default output encoding in Python 2 is a well-known idiom: sys.stdout = codecs.getwriter("utf-8")(sys.stdout) This wraps the sys.stdout object in a codec writer that encodes output in UTF-8. However, this technique does not work in…
Greg Hewgill
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The difference between stdout and STDOUT_FILENO

I was wondering the difference between stdout and STDOUT_FILENO in Linux C. After some searching work, I draw the following conclusion. Could you help me review it and correct any mistake in it? Thanks stdout belongs to standard I/O stream of C…
Bing Lu
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Silence the stdout of a function in Python without trashing sys.stdout and restoring each function call

Is there a way in Python to silence stdout without wrapping a function call like following? Original Broken Code: from sys import stdout from copy import copy save_stdout = copy(stdout) stdout = open('trash','w') foo() stdout = save_stdout Edit:…
Tim McJilton
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