Pipes or named pipesĀ are a feature of the POSIX standard that allow separate processes to communicate with each other without having been designed explicitly to work together.

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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. ...
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2answers
40 views

Win7 Command Line piping

I want to know why in the command line prompt this happens. I have a script fileX.cmd which is one single line of text: @echo dir If I do C:\Users\Dogfood>fileX.cmd | cmd This will show all ...
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49 views

Use grep to find files and pipe/open to open them

How can I pipe files from grep to open all matching files? I've tried grep -li "type" * | open, but that does not work.
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1answer
900 views

Rendering HTML from a pipe

I would like to be able to generate HTML then pipe it to a program which will render it, something like this: for i in 1 2 3 do for j in a b c do echo "<table ...
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1answer
74 views

.cmd script output only goes to pipe occasionally

I'm having a problem with a .cmd script only occasionally passing it's output through a pipe. The script is auto generated by npm and it runs jshint using node. Here's the script: :: Created by npm, ...
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1answer
39 views

Pipeing lines to repeat commands

If my grep operation returns a list of ID's like: 12345 84758 49549 .. can I somehow feed/pipe each line to a commandline command's parameter? Like for example with the above result from grep, I'd ...
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1answer
147 views

SoX pipe operations and data loss

When piping operations using SoX, I've noticed that files get shorter than they should: Works fine: sox -n -r 44100 silence.wav trim 0 1 sox --combine sequence silence.wav combined.wav soxi -D ...
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1answer
653 views

How to solve “Broken Pipe” error when using awk with head

I'm getting broken pipe errors from a command that does something like: ls -tr1 /a/path | awk -F '\n' -vpath=/prepend/path/ '{print path$1}' | head -n 50 Essentially I want to list (with absolute ...
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1answer
465 views

pipe from ssh to windows “ssh server 'tail err.log' | tool.exe”

I want to live monitor a logfile generated on a remote linux host with a windows tool. I'm looking for something like: $> ssh remoteserver 'tail -F /var/log/err.log' | tool.exe But on Windows. ...
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1k views

Add custom time to video frames using ffmpeg

I am using ffmpeg to encode raw pixels data (bgr32) into a video file. Pixels data is being sent from java application to ffmpeg stdin pipe. I am looking for a way to add a timestamp overlay to each ...
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1answer
242 views

Why does echo work through pipe but not cat with msmtp?

This works: echo "yada yada" | msmtp my@mail.com but not this: cat yadayada.txt | msmtp my@mail.com which delivers the email with empty content. Why does echo work through pipe but not ...
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133 views

redirect awk information to stdout

I am trying to gather information for CPU use for all the processors in a text file. mpstat -P ALL -u 1 | awk '{print $4}' > cpu.txt && mptat -P ALL -u 1 | awk '{print $4}' | tee cpu.txt ...
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465 views

OS X: log text from serial port

I have a text stream coming in on a USB-RS232 adapter. I want to pipe it to some Unix tools, to a file, whatever. What is the simplest way to do so? Does it really require third-party software? OS X ...
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228 views

pipe unlimited curl stdout into chunked files

I've got an HTTP-endpoint that serves an unlimited stream of events. Now I'd like to record that stream using curl, but splitting the recorded files at the same time - preferably based on the line ...
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0answers
1k views

'No such interface supported' when attempting to compress file through 7zip commandline

When I run the 7zip commandline: > echo foo | 7za a arc.7z -sifoo.txt Everything works as expected, but if I try to do: echo foo | 7za a arc.zip -sifoo.txt I get the following: ...
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67 views

Pipe ffmpeg->ffmbc cut files after some length

I recently tried the following command: ffmpeg.exe -i "C:\Users\Dennis\git\cnn\CNN\watch\filea.mp4" -i "C:\Users\Dennis\git\cnn\CNN\watch\fileb.mp4" -filter_complex ...
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10 views

Merge two outputs into one in real time without scrambling them in linux

Is it possible to merge two real time outputs into one file without scrambling the new lines? What I want to do is something like cat <(/proc/kmsg) <(while true; do echo hello; sleep 1; done) ...
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47 views

Multiple grep command and show after line

I have this command grep -iE -A18 "$(date +"%Y-%m-%d").*error" * | grep -v -A18 'Movig to Error Queue' but the result shows me the 18 line after 'Moving to Error Queue' but I do not want that. I ...
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11 views

remove permission spam for find is not working tcsh enviroment

Hello this question is asked a lot like here: However, my environment on (csh or tcsh) seems to add a space but I can't figure out why. for instance, on bash: find /. -user `whoami` 2>/dev/null ...
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102 views

Using pipes on ffmpeg has different behaviour than using files

I am using pipes to provide input and to send out output from FFmpeg The command I use is essentially ffmpeg -i pipe:0 -f flv pipe:1 I am using a Java program that basically provides an input ...
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41 views

redirect tar notices when used with pipe

I have a remote backup cron script that contains the following line: cat ${list} | xargs tar Jlcf - | ssh -i /root/.ssh/backup \ seron@dummy.net "backup_${DATE}.txz" It gives tar a list of ...
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101 views

ffmpeg set duration when muxing from fifos to pipe

I'm trying to mux two files (audio and video) coming from fifos and to output the result to a pipe. The input files are one mp4 h264 file and a m4a aac, and the output file should be a matroska ...
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139 views

error with upstart script

Further to my last question, I'm now using logger. I have the following upstart configuration start on runlevel [2345] stop on runlevel [06] respawn pre-start script exec 2>&1 > ...
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127 views

Force FFMPEG to honour timestamp when receiving raw frames

My app interface is recorded with FFMPEG: ffmpeg -f rawvideo -vcodec rawvideo -s,1280x720 -pix_fmt argb -r 15 -i - -c:v libx264 -b:v 1024k result.mp4 All works very well except that the output ...
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230 views

No prompt for password when piping through ssh

i'm trying to use partclone to clone a partition and send the .img on my ssh server.That's what i do : partclone.ext2 -c -d -s /dev/sda1 | ssh -p xxxxx username@serveraddress "cat > backup.img" when ...
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58 views

how do you monitor the progress of a command line program?

We have some custom command line programs at our Windows shop. These commands are scheduled to run (from within bat files) at regular intervals using the Task Scheduler. Our tasks pull data from ...
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357 views

mysqldump to local mysql database through ssh

This command: ssh bruchowski@www.example.com 'mysqldump -u bruchowski -p dbname' > mysql -u root dbname Produces this error: mysqldump: Got error: 1045: Access denied for user ...
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99 views

mutt colorizing piped messages

Viewing messages in mutt are colorized, but piping them through the less pager removes colorization. How do I preserve message colorization? I've tried: | less -R but colorization is stripped ...