Stdout is the standard output stream is the default destination of regular output for applications.

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10
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3answers
248 views

Two Programs having their StdIn and StdOut tied

Suppose I have two programs called ProgramA and ProgramB. I want to run them both simultaneously in the Windows cmd interpreter. But I want the StdOut of ProgramA hooked to the StdIn of ProgramB and ...
0
votes
2answers
14 views

How to terminate a cli app when stdout contains a certain string?

I've got a command line app that outputs lots of information to stdout. How can I terminate the program when stdout contains a certain string? e.g. something like: my_program | ...
0
votes
0answers
30 views

See contents of conhost

Every now and then, various programs create conhost.exe processes on my (Windows 7 x64) computer. I know they are console windows, except the windows themselves are hidden. I don't suspect any ...
0
votes
1answer
37 views

how to see the output of a cron/at jobs while it is still running?

The output of a cron or atq job is automatically send by email to the user, when the job is finished. However I am running a time consuming script, and I would like to check that it is running ...
1
vote
1answer
49 views

PowerShell v5: Suppress Out-Default output in nested functions

I'd like to suppress any output then function_b is invoked: Function function_a { "test" | Out-Default } function function_b { [CmdletBInding()] param() function_a } # These are ...
1
vote
0answers
18 views

Parsing (or Converting) Buffered Output

If a dynamic, text-based, CLI application doesn't include an option for producing unbuffered text output; what options do I have for parsing said output? Can it be converted to a more appropriate ...
1
vote
1answer
63 views

Redirect STDERR and STDOUT to file with timestamp on each line

On my CentOS I am trying to execute a php script that contains an endless loop to do some fancy stuff inside. It doesn't matter that an endless loop may not be an accurate solution for most cases, but ...
0
votes
1answer
37 views

How to stop background processes from outputting permanently?

In my newly installed Lubuntu virtual machine terminal, when I run firefox & firefox runs in the background, but it keeps on outputting in my terminal. I found a way to stop it from another ...
0
votes
1answer
112 views

How to echo only 1st line from 'curl' command output?

I'm trying to get only first line of the curl command output. (Sorry if this is confusing) Let's say, for an instance, i run simply: # curl http://localhost <!-- This is the hidden line i want to ...
1
vote
2answers
34 views

How to unset a “>” echo in Linux

I've just realized I don't know how to unset an echo I set with >. The exact current situation is I just set dmesg > /var/log/syslog and now wanted to unset it, realizing I've never done that ...
0
votes
0answers
52 views

stdout of my app visible in cygwin bash.exe, and not visible in mintty.exe

I have a simple c program with printf("start\n");. When I run it from bash.exe -i -l, I can see the stdout. When I run it from mintty.exe, I can't see it. How can I make it visible thru mintty.exe as ...
1
vote
1answer
142 views

reading stdout in pipeline using “-” fails for “docker exec”

I want to launch a bash terminal for my Docker instance by piping the first container ID to docker exec: docker ps | head -2 | grep -v CONTAINER | cut -d' ' -f1 | docker exec -i -t - bash The final ...
1
vote
1answer
34 views

Unexpected BPython console output behaviour

I am using BPython to run Python scripts, and I found the console output has a different behavior than the regular Python console.. For example this small snippet: import time for i in range(100): ...
2
votes
4answers
197 views

python2.7 from macports stdin issue

My python2.7 from macports seems to mess up with osx terminal in a weird way. Here is what I mean. The exact input from the keyboard was: /opt/local/bin/python2.7<ENTER> a = 3<ENTER> a&...
0
votes
1answer
99 views

How to get stdout of a “lost” session

I don't well what's the name of the situation, I think yesterday I closed a session with a background ipython process, but I am still able to connect to it (the process is running a web server and I ...
0
votes
1answer
25 views

Weird result of initiating a variable with the output of 'git describe'

For some reason this assignment: OUT=$(git describe HEAD) prints to the stdout (for example): fatal: No names found, cannot describe anything. Is this a normal behavior? Why doesn't this happen with ...
0
votes
1answer
49 views

Modify terminal STDOUT/STDERR to change the line colour based on a REGEX

Is this possible? What I would like to achieve is when running unit tests (Python) to highlight any line which matches the path to the current project directory and leave other output untouched. ...
0
votes
2answers
166 views

Redirect stderr to second terminal / tty

I've tried things like rse to differentiate standard-output and standard-error streams from a program; but I'd really like the option of viewing the two in separate terminals, without redirecting to a ...
0
votes
1answer
350 views

Using PuTTY SSH, how do I capture the remote output of a command?

In Linux ssh me@server "echo this ran remotely" The output this ran remotely is put to standard out. This is perfect. In Windows echo "echo this ran remotely" > test.cmd putty -i privatekey....
2
votes
1answer
1k views

shell standard streams redirection order OR 2>&1 1>/dev/null vs 1>/dev/null 2>&1

Can somebody please clarify differences? Is some of those considered as best practice? If I remember correct I somehow on SO read that this 1>/dev/null should precede this: 2>&1 ls -al /...
0
votes
1answer
47 views

Which is the preferred approach to pass command/script arguments to a log file?

Generally, I am wondering how I can pass the arguments from a terminal command to stdout. More specifically, I am using tar as part of my backup process and I would like the parameters (especially ...
1
vote
1answer
315 views

How to split and recombine stdout pipe in bash?

I am parsing text on the command line. How can I take the output of one command and use it in two places in the next command? some_command | head -n $( awk '/search_term/ {print FNR} ...
0
votes
1answer
254 views

`if` statement with stdout && passing xargs through pipe

Say I have a list.txt of files I want to check. cat list.txt and for each file, I want to perform an action cat list.txt | xargs -I {} touch {} But depending on the outcome of the action, I want ...
1
vote
2answers
33 views

How do I output a variable without changing if it has a newline or not in a shell script?

I have a shell script that takes input from another shell script. The stream gets piped in on stdin. I need to capture all the bytes of the stdin stream to a single variable in the shell script. Then,...
0
votes
0answers
14 views

How to get stdout of another program [duplicate]

Some Linux program prog1 permanently prints to console. I'd like to read and analyse it's stdout in my C program prog2 as stdin. I can't change prog1 source. I expect something like this command: ...
1
vote
1answer
2k views

Receiving FFMPEG error -22 when piping data to stdout

I am attempting to use FFMPEG to transcode avi files to mp4 and pipe the data to stdout using the following command (technically through NodeJS, but I receive the same error when executing the ...
1
vote
2answers
1k views

How to quieten tcpdump output when reading a pcap file?

I notice that when using tcpdump to read a pcap file, the tcpdump command somehow manages to print information to my console even when I redirect both STDOUT and STDERR. How can I prevent tcpdump from ...
0
votes
2answers
1k views

How to redirect a part of stderr and stdout to /dev/null

My program outputs to stderr and stdout. I want to grep for "pattern" either in stderr and stdout. And I want the rest to be sent to /dev/null. If I pipe after redirect stderr : ./prog 2>/dev/null ...
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vote
2answers
462 views

Stdout and stderror in CentOS

I am exec command: yum info mcrypt | grep -i error > /dev/null yum info mcrypt | grep -i error 2> /dev/null But i see: Error: No matching Packages to list How I can hide this messasge ...
2
votes
1answer
325 views

Using the same file as stdin and stdout results in empty file

If want to filter a file but if I use the same file as input and output the output file is empty. Is there another solution instead of using a second file? php -r "echo preg_replace('~/\* DEV \*/(.*)/...
2
votes
1answer
963 views

How can I pipe the output of *all* entered shell commands into another? (e.g. pipe everything into 'lolcat')

Good Afternoon, (OS X user) I am specifically trying to pipe the output of every shell command I type into the ruby gem 'lolcat' (which makes the output to the terminal rainbow colored). Is there a ...
2
votes
1answer
328 views

What happens if dd encounters errors while output of dd is being piped to gzip?

Suppose that dd if=/dev/sda bs=100M | gzip -c > somefile.img.gz is done. If errors occur in dd, do I get to see error messages in terminal, or do they get ignored? Also, suppose that dd ...
19
votes
3answers
3k views

Why does the output of some Linux programs go to neither STDOUT nor STDERR?

Why does the output of some Linux programs go to neither STDOUT nor STDERR? Actually, I want to know how to reliably capture all program output, no matter what 'stream' it uses. The problem I have is ...
2
votes
4answers
8k views

How can I stop cat output immediately despite massive output?

I'm looking for someway to stop the output to STDOUT when I realize a command is wrong. For instance, if I accidentally cat a very large file. Usually it will eventually stop if you hold down ctrl + c,...
3
votes
2answers
300 views

Any way to view stdout of a program after it has been started in gnome-shell?

So, if I run a program through the menus in gnome-shell, is there a way to view stdout and stderr? Or is there some kind of hack to achieve this functionality? Or is everything just sent to /dev/null?...
46
votes
2answers
21k views

Can I make cURL fail with an exitCode different than 0 if the HTTP status code is not 200?

I was always assuming that when curl got an HTTP 500 response it was returning an exit code that meant failure (!= 0), but that seems to be not the case. Is there a way I can I make cURL fail with an ...
1
vote
3answers
2k views

zcat | head : write error from large gz file

I was trying zcat to get only the first 1M lines of a compressed .gzip file into a new one. However, I get the following error: $ zcat path/to/R2.fq.gz | head -100 >R2.fqtest head: write error: ...
4
votes
1answer
1k views

Why can I see password prompts through redirecting output?

So, I've got a command that I'm issuing that is essentially 'ssh'ing into various hosts: command 2&>1 | grep "desired output" Every once in a while, in the midst of the command, it'll run ...
1
vote
1answer
2k views

How to get rid of UDP checksum error messages in virtual console?

Whenever I am streaming a video in the web browser, while connected to my school LAN via ethernet, and switch to the virtual console (ctrl-alt-f1) on Ubuntu, I get an error that looks like the ...
1
vote
2answers
506 views

reading output of a python file being logged in the console

I started playing with the logging module in Python recently. My output gets sent to a log file now. So far, so good. But I'd also like to be able to keep tabs on it in progress, without dealing with ...
2
votes
1answer
191 views

Is it possible to send the output of -w and -o Curl streams to different files? How?

I'd like to run a curl command, grep the output (response payload) for some keywords, then also print some metrics via the -w option. I think this would be easy to do if I could direct the -o ...
1
vote
1answer
678 views

Redirecting to /dev/null and a file at the same time

I'm trying to execute the following command: find . -name ".[ch]" | xargs grep -in pattern > file There are some errors that are printed on stderr because a few files are not found. How can I ...
2
votes
2answers
834 views

Any way to stream a file in linux

I have a terminal output which I'd like to be available to several users currently something like: command > /var/logs for the input, and: watch tail -30 /var/logs for the input terminals. ...
7
votes
4answers
4k views

Determine if output is stdout or stderr

How can I determine if what a process is outputting is stdout or stderr?
4
votes
2answers
4k views

Redirect stdout to a file when process is run in background

How can I redirect the stdout of a program to a file when it's run in the background? I have a program that generates output every second. When I run it normally and redirect to a file, the output ...
2
votes
1answer
1k views

How to open the stdout with Notepad++?

On OSX TextMate have the alias mate which you can use with the pipe to open other program's stdout. How can I achieve the same effect in Windows 7 with Notepad++? Ex.: git diff master|edit
21
votes
2answers
13k views

Pipe gunzip and mysql to gunzip a dump and import it

I have a .gz sql dump file (example: foo.sql.gz) that i want import in my database with the classic mysql command. gunzip -c foo.sql.gz > foo.sql mysql -uroot -ppassword foo < foo.sql foo is ...
11
votes
1answer
3k views

Copy terminal output to Mac clipboard?

I need to directly copy the terminal stdout to the clipboard on Mac. How would I do this? Example: echo sometext | copy_to_clipboard or echo sometext > /private/clipboard.txt
3
votes
3answers
4k views

Encrypting to standard output with gnupg

I'm trying to encrypt something with gpg -a and return the result to standard out rather than a file. According to the manual, it should be sufficient to omit an --output flag, but that doesn't seem ...
1
vote
1answer
1k views

How can you move (or copy) all files of a certain type to a directory in Unix?

I'm not very familiar with all the tricks of grep/find/awk/xargs quite yet, so be patient with me =] I have a particular file type say *.xxx, in random places throughout a certain directory. How can ...