# \#pipes

**URL:** https://discourse.julialang.org/tag/pipes/807.md

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## [Running commands in sequence in a pipeline](https://discourse.julialang.org/t/running-commands-in-sequence-in-a-pipeline/51374)

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**Author:** [@nstgc](https://discourse.julialang.org/u/nstgc)\
**Replies:** 15\
**Last updated:** [November 25, 2025, 12:47pm UTC](https://discourse.julialang.org/t/running-commands-in-sequence-in-a-pipeline/51374 "2025-11-25T12:47:17Z")

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I am writing a script which—at least in BASH—best works with subshells. The basic structure is “(do something; do something else; etc.) | the next thing|…”. A minimal working example (in BASH) would be: (echo -n "Hello …

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## [Set up pipe between existing Julia processes](https://discourse.julialang.org/t/set-up-pipe-between-existing-julia-processes/118960)

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**Author:** [@lmtzx9h4qqnt](https://discourse.julialang.org/u/lmtzx9h4qqnt)\
**Replies:** 6\
**Last updated:** [September 3, 2024, 2:43pm UTC](https://discourse.julialang.org/t/set-up-pipe-between-existing-julia-processes/118960 "2024-09-03T14:43:31Z")

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Is there a way to set up a pipe between two Julia process that are already running, assuming that the two already have another method of communication to execute code (example: worker process on the same machine started …

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## [Macros and piping](https://discourse.julialang.org/t/macros-and-piping/116130)

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**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 14\
**Last updated:** [June 25, 2024, 11:58am UTC](https://discourse.julialang.org/t/macros-and-piping/116130 "2024-06-25T11:58:57Z")

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How come these two examples don’t work. using Pipe, Chain macro test(x) x end @pipe 1 |\> @test(\_) #works @pipe 1 |\> @test \_ #works @pipe 1 |\> @test #doesn't work @chain 1 begin @test(\_) …

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## [Command hangs: \`run(pipeline(\`git diff\`, stderr=err, stdout=out), wait=true)\`](https://discourse.julialang.org/t/command-hangs-run-pipeline-git-diff-stderr-err-stdout-out-wait-true/103742)

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**Author:** [@adomasbaliuka](https://discourse.julialang.org/u/adomasbaliuka)\
**Replies:** 3\
**Last updated:** [September 21, 2023, 9:05am UTC](https://discourse.julialang.org/t/command-hangs-run-pipeline-git-diff-stderr-err-stdout-out-wait-true/103742 "2023-09-21T09:05:43Z")

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(Found while debugging DrWatson.jl) Setup (git repo with changed file): # julia 1.9.3, Commit bed2cd540a1 (2023-08-24 14:43 UTC) shell\> mkdir JuliaGitWithPipeHangs shell\> cd JuliaGitWithPipeHangs shell\> git init Initia…

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## [Help me understand pipes - strange behavior](https://discourse.julialang.org/t/help-me-understand-pipes-strange-behavior/102224)

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**Author:** [@andromodon](https://discourse.julialang.org/u/andromodon)\
**Replies:** 6\
**Last updated:** [July 29, 2023, 9:44am UTC](https://discourse.julialang.org/t/help-me-understand-pipes-strange-behavior/102224 "2023-07-29T09:44:07Z")

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I’m running into something really strange for me in a pipeline. Can someone please explain why these two produce different results? julia\> "0X" |\> x -\> collect(UInt8, x) .|\> x -\> x == UInt8('X') ? UInt8(':') : x .|\> x -\>…

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## [Find whether a Julia script has the output redirected to the screen or a pipe?](https://discourse.julialang.org/t/find-whether-a-julia-script-has-the-output-redirected-to-the-screen-or-a-pipe/100365)

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**Author:** [@RaulDurand](https://discourse.julialang.org/u/RaulDurand)\
**Replies:** 2\
**Last updated:** [June 14, 2023, 9:48pm UTC](https://discourse.julialang.org/t/find-whether-a-julia-script-has-the-output-redirected-to-the-screen-or-a-pipe/100365 "2023-06-14T21:48:31Z")

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How do I find whether a Julia script running in the terminal has the output (stdout) redirected to the screen or a pipe? $ ./julia\_script # outputs to the terminal $ ./julia\_script | command # pipes the output

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## [Purpose of secure\_cookie in Electron.jl](https://discourse.julialang.org/t/purpose-of-secure-cookie-in-electron-jl/68296)

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**Author:** [@ettersi](https://discourse.julialang.org/u/ettersi)\
**Replies:** 3\
**Last updated:** [September 17, 2021, 8:25am UTC](https://discourse.julialang.org/t/purpose-of-secure-cookie-in-electron-jl/68296 "2021-09-17T08:25:00Z")

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When Electron.jl launches a new electron process, it passes a secure cookie which is then used to authenticate the electron process when it tries to connect back to the Julia process. I’m not sure I understand the purpos…

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## [Reading lines from a pipe without hanging at the end](https://discourse.julialang.org/t/reading-lines-from-a-pipe-without-hanging-at-the-end/69524)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 3\
**Last updated:** [October 12, 2021, 4:01am UTC](https://discourse.julialang.org/t/reading-lines-from-a-pipe-without-hanging-at-the-end/69524 "2021-10-12T04:01:02Z")

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Suppose you want to run a command, read the output, and return some processed version of the output… for example this code parses the output of “traceroute”… function gethops(dname) trin = Pipe() trout = Pipe…

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## [Piping into an external program from Julia output](https://discourse.julialang.org/t/piping-into-an-external-program-from-julia-output/42691)

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**Author:** [@nstgc](https://discourse.julialang.org/u/nstgc)\
**Replies:** 16\
**Last updated:** [December 8, 2020, 9:24pm UTC](https://discourse.julialang.org/t/piping-into-an-external-program-from-julia-output/42691 "2020-12-08T21:24:48Z")

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What I’m trying to do is process a bunch of files with a Julia function, which then is fed into an external program, and fed again into a Julia function. So basically func1(file) | run(\`CMD\`) |func2(stdin) which made …