Standard error is another output stream typically used by programs to output error messages or diagnostics.

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How do I output stderr/stdout of my script to both a file and the console?

I'm using Amazon Linux and writing a script in bash. I want to output both stderr / stdout (preferably in the order that they occur) to a file as well as the console. However, this command isn't ...
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2answers
90 views

Different error messages when using different strings in terminal

When I insert, for example, unix.stackexchange.com followed by Enter in terminal, I get the following error: unix.stackexchange.com: command not found This is ok and as I expected. But when I insert ...
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241 views

Redirecting standard error output to bash variable

Here's a C code snippet that will cause segfault: // segfault.c #include <string.h> int main() { memset((char *)0x0, 1, 100); return 1; } Compile it with: gcc segfault.c -o ...
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1answer
20 views

Unable to redirect stdout/stderr to log file [duplicate]

I have a script tmp.sh #!/bin/bash echo hello sleep 3 echo 3 I want to log the script running time (as well as script stdout) to a log file. user$ time ./tmp.sh >& log.tmp real ...
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10 views

redirect the output of {time}

I am trying to benchmark a single request agains a webserver, and am having a problem doing so, specifically, I am having an issue redirecting the output of the time command. If i simply run time ...
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2answers
26 views

Redirect stdout to file with nohup doesn't work

I'm trying to run a C-program in the background. I also want to save the stdout-outputs of the program. But if I try the following, nohup only redirects stderr-outputs to the logfile.txt: nohup ...
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2answers
28 views

I want to catch the STDERR and STDOUT of Background running script

I have to run a script background and also i have to catch the STDERR and STDOUT . i'm using the below line . test.sh & >> log_file 2>&1 But un fortunately nothing is getting ...
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3answers
516 views

sending output to /dev/stderr vs. >&2

In scripts, errors are usually sent to file descriptor 2 with &2, ie: echo "error" >&2 Sometimes /dev/stderr is used instead: echo "error" > /dev/stderr Looking at /dev/stderr, I ...
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1answer
28 views

`docker logs foo | less` isn't searchable or scrollable but `docker logs foo 2>&1 | less` is

Using either one gives readable text. But only with the stderr redirect can one scroll or type /somepattern and get matches. Without it searching gives "Nothing to search (press RETURN)" and a ...
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3answers
188 views

Trying to make sense of bash redirection syntaxes and their outputs

I'm new to Linux and trying to understand how redirections work. I have been testing various syntaxes for redirecting stdout and stderr to the same file, which don't all produce the same results. ...
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62 views

shell stderr to /dev/null

I have PID file and I want to get PID number so this is what I am doing. [root@linux ~]# PID=`cat /usr/local/foo/var/run/foo.pid` [root@linux ~]# echo $PID 3414 sometimes this file doesn't ...
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0answers
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Suppress warning of rbenv versions if no rubies installed

At the moment I'm working on Ansible role that installs ruby with rbenv. In order not to install same ruby version every time I run setup task I have to check that no needed ruby is already installed. ...
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1answer
258 views

How can I pipe only stderr in zsh?

In bash: $ echo hi 2>&1 1>/dev/null | cat $ While in zsh: $ echo hi 2>&1 1>/dev/null | cat hi $ Is there a way to pipe only standard error while redirecting standard out?
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2answers
71 views

Output is in console but not part of stdout or stderr

I have a command that outputs the following: READY Listening.... HELLO READY Listening.... TEST It is speech recognition from pocketsphinx_continuous. I need that output redirected to a file, and ...
2
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3answers
35 views

What is regarded as “ideal” in relation to using stdout/stderr for output in different situations?

I have seen stdout and stderr used in a variety of different ways - as far as I understand, it is common to use stdout for general information and stderr for errors and the like. However, I have also ...
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2answers
161 views

how to redirect output of ssh to a file

I want to make ssh connection to my server but I don't want to enter password. I want to save output to a file like so: $ ssh root@x.x.x.x -p 22 1>output 2>&1 but when I run it the output ...
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0answers
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Stop stdout log being clipped (by heroku-local)

I run heroku local with the Procfile: web: start-nginx gunicorn -c gunicorn.conf.py app:app start-nginx does some environment setup, and then ends with: { nginx --some-params & $@ ; } the ...
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stderr over ssh -t

This sends output to STDERR, but does not propagate Ctrl+C (i.e. Ctrl+C will kill ssh but not the remote sleep): $ ssh localhost 'sleep 100;echo foo ">&2"' This propagates Ctrl+C (i.e. ...
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2answers
116 views

Duplicate stdin to stdout and stderr, but in a synchronized way

I need to duplicate the stdout of a producer and feed it to two consumer in a synchronized fashion. consumer 1 producer | duplicator | consumer 2 ...
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2answers
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nohup: ignoring input and redirecting stderr to stdout

I am starting my application in the background using nohup as mentioned below - root@phx5qa01c:/bezook# nohup java -jar ./exhibitor-1.5.1/lib/exhibitor-1.5.1-jar-with-dependencies.jar -c file ...
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6answers
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Can I configure my shell to print STDERR and STDOUT in different colors?

I want to set my terminal up so stderr is printed in a different color than stdout; maybe red. This would make it easier to tell the two apart. Is there a way to configure this in .bashrc? If not, is ...
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2answers
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Does `Segmentation fault` message come under STDERR?

I ran an executable in bash ./code > log It shows occasional error messages on terminal whereas all printf statements go into log file. I re-run it like below ./code >& log Now, the ...
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2answers
648 views

How to redirect unzip -v output to a log file in shell script [duplicate]

I have a script that loops through all zip files in a large directory and individually unzips them. I am using the -q option in order to keep the console clean and display other monitoring info. I ...
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3answers
60 views

What is `>&` in simple terms? [duplicate]

What does $ command 1>&2 do? As I understand it this runs the command but with the STDOUT redirected to the STDERR. But I'm not sure exactly how >& works. I have seen it as $ command ...
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2answers
339 views

stderr gets flushed before stdout, when using file logger

My python code: import sys print "i am a daemon" print "i will be run using nohup" sys.stderr.write("i am an error message inside nohup process\n") When i run the code as python a.py, it shows, i ...
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516 views

Throw away standard output and error

I have redircted my ouput using /dev/null in bash script but it is still throwing an error. Code is following ps -p $proc | fgrep $proc> /dev/null if [ $? -ne '0' ] ; then ...... fi below is ...
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Inconsistency of stderr redirection between tcsh and other shells

I'm running into issues with redirection in tcsh. Consider the following commands: vi --version and vi --xxx. And let's assume this is on a machine where vi supports the --version option. The ...
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2answers
141 views

CSH and all output (with errors) to file

I need save all output from compilation to file. I have many errors "undefined reference" and I want see all of these errors. I try "makeall >& out", but in file "out" aren't any of error ...
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2answers
6k views

suppress stderr messages in a bash script

Consider the following (slightly silly) script name 'test1.sh': #/bin/bash # sleep 10 & echo sleep pid = $! pkill sleep When I run it, I get not only the output of the echo, but bash's ...
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1answer
788 views

Redirecting Standard Output And Standard Error to One File [duplicate]

I have come to understand that we have two methods of redirecting both stdout and stderr to the same file. The first method is: ls -l /bin > ls-output.txt 2>&1 As the author of this book ...
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1answer
117 views

capture log of ufsdump when backup to stdout

I am backing a file system with ufsdump. In order to gain space in the remote file system I backup to stdout then pipe the output to compress. I find is more efficient that backuping up and then ...
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3answers
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Copy stdout and stderr to a log file and leave them on the console within the script itself

Using bash, how do I copy stderr and stdout to a log file and also leave them displayed on the console? I would like to do this within the script itself using an exec. I tried with exec ...
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2answers
163 views

How can I redirect the same message to both stdoud and stderr (without temporary object)

It is easy to redirect stdout or stderr to the same output (file or one of the 2 std output) with a 1>&1,>&2 and/or >file. Is there a way to send the same output to both the std ...
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3answers
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Write to stderr

I'm using stderred to color all output streamed to stderr red. It's working fine. But when I write my own bash script and throw an error with echo 'error' 1>&2, it doesn't color the output in ...
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1answer
132 views

Using find -exec and having trouble with redirecting standard error

I have an individual.sh script that pipes standard error to a grep command, like this: FOUND=$(tesseract "$i" out -psm 0 |& grep -ci 'Orientation in degrees: [^0]') If I run the script like ...
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2answers
87 views

Output piped content to file and show number of lines in the file on stdout

I would like to use tee to pipe content from stdout and stderr respectively into files (in fact append it with > >(tee -a $filename)). However, instead of seeing the contents appended to the ...
4
votes
1answer
152 views

unexpected output with grep

I am using pyrit. For those who dont know, pyrit allows among other things to check if a wpa handshake key is valid: pyrit -r file0.cap analyze when a file does not contain a valid key, here is ...
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4answers
401 views

A command that generates both standard error and output

I want to do some troubleshooting on my bash script. Is there a short and simple command that generates both stdout and stderr so that I can use 2>&1 on it? Sorry if this looks trivial, but I ...
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2answers
4k views

How do I suppress a warning message?

touch ~/deleted/$(echo "directory_"$(readlink -f foo)|tr '/' '\') 2> /dev/null where foo is a directory It's reading the full pathname of foo and creating it as a file replacing all '/' with '\' ...
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0answers
37 views

Show error messages and information that a program was killed on another terminal [duplicate]

If I open a program, say evince, from the GNOME GUI, it is not attached to a terminal. If I send it a signal, it acts accordingly but nothing shows up in my terminal. If I were to open it in a ...
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0answers
16 views

Test execution output of a command before a pipe [duplicate]

I would like to test the execution of a php script that redirect its stdout and stderr to a file with tee. php /path/to/script --param 2>&1 | tee -a /path/to/log if ( test $? -ne 0 ); then ...
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2answers
525 views

How do I enable &>/dev/null by default for all sh/bash commands?

Is there a way to make &>/dev/null the default behavior in a sh/bash script? I' rather not have to appended this to every command within the console, not an *.sh script. I'm looking to make a ...
5
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3answers
9k views

stdin, stderr, redirection and logs

Is there a difference between those two lines ? /home/user/script.sh >> /home/user/stdout_and_error.log 2>&1 /home/user/script.sh 2>&1 >> /home/user/stdout_and_error.log ...
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4answers
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Can a running script identify the logging context?

Let us say I redirect the STDOUT, STDERR of a program to files. ./script.sh 1> output.log 2> error.log Can the running program find this out i.e. know the paths to these files?
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2answers
2k views

Redirect grep error output to file

I wanted to capture to a file the errors being returned on the command line from grep. For example, grep foo.lookup No such file in directory I want to output that to a log file. This is my shell ...
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1answer
254 views

Can redirecting stdout and stderr to the same file mangle lines?

I've read that when redirecting stdout and stderr to the same file using 2>&1, stdout is usually block buffered while stderr is unbuffered. If a very long line is written to stdout, requiring ...
3
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1answer
98 views

What is the relationship between a program's output, standard output, and its file descriptors?

Let's assume that I am running wget which is downloading something. It's printing some text to my terminal and writes the downloaded data into a file. From a terminology point of view, what is the ...
1
vote
1answer
210 views

Pipe not picking up stdout

I am running a java program from a OS X 10.8 bash terminal, and are trying to rederect the output it is producing. However, when either running this throug a pipe, or rederecting it to a file, the ...
2
votes
1answer
65 views

aptitude produces output twice

For quite a while, I get a double output of some messages from aptitude. Here’s an example: > sudo aptitude install mpw Couldn't find package "mpw". However, the following packages contain "mpw" ...
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487 views

How to run a command while logging output to a file?

I have a console application that needs to be run as part of the deployment of a new application version on my server. This console application is designed to output to the console, and cannot be ...