All Questions
11 questions
1
vote
1
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3k
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How output one command with tee to standard ouput and also to pipe it to another command?
Maybe this is duplicate, I have not found any answers though, but how to use pipe to output one command to multiple outpus (e.g. send it to pipe, stdout, or command substitution)?
I have this line:
$ ...
- 350
0
votes
1
answer
2k
views
echo, pipe and command substitution
I want to substitute an echo command followed with | (pipe). For example,
$(echo "echo 'hello' | cat")
returns
'hello' | cat
I expect this to behave like
echo 'hello' | cat
which returns
hello
but ...
- 113
3
votes
2
answers
1k
views
Difference between piping and command expansion
This link is relevant What's the difference between substitution and piping to bash but I am not quite understanding everything that is being said.
What is the difference between piping command1 ...
- 561
5
votes
1
answer
350
views
Pipelined Sed does not work on found filename inside Bash command substitution when invoked from Find "-exec" [duplicate]
It looks like 'find', 'bash' and 'sed' in some cases does not work as one expects.
The following example should first create file 'sample.txt', then find the file and finally process it by '-exec' ...
- 153
3
votes
2
answers
2k
views
blocking/non-blocking pipes/redirects inside command substitution
I observed the following behaviour in bash:
{ echo 'foo' ; sleep 10 ; }
-> standard output "foo" appears immediately, after 10 seconds the command is done (as expected)
{ echo 'foo' ; sleep 10 ; } &...
- 133
0
votes
1
answer
474
views
capturing subshell command substitution output
I'm trying to capture the output of a command substitution. This works until a pipe is added to the command. Am I doing something wrong or is this a quirk of mingw?
$ bash --version
GNU bash, version ...
- 103
3
votes
3
answers
2k
views
Processing a single file as both input and output throughout pipes [duplicate]
Good evening,
I would like to filter a file's content with some piped commands and then write the result back to the same file. I know, I can't do that the way I wrote it. Hold on …
This is the ...
- 341
0
votes
3
answers
117
views
Saving a piped value went wrong
I installed jq to handle some JSON with bash.
But somehow piping the JSON string to jq in combination with saving it's output to another variable went wrong.
TEST='{"foo": "bar"}'
PB_SIG=$TEST | jq '....
- 123
3
votes
1
answer
3k
views
Why doesn't PIPESTATUS work on pipelines within a command substitution
Proof below: Bash 4
Prompt> $(echo hello|sed 's/h/m/'|xargs -I{} ls {} 2>/dev/null|sed 's/ /_/')
Prompt> for i in ${PIPESTATUS[@]}; do echo $i;done
Output> 0
Prompt> echo hello|sed '...
- 7,736
7
votes
2
answers
1k
views
"command | less" vs "less <(command)"
A common "idiom" for viewing large amounts of command output is to pipe it to less, via command | less. However, it's also possible (perhaps only in bash, haven't tested in other shells) to use the ...
- 228
6
votes
2
answers
6k
views
Piping to the command substitution of a string containing pipes
This works—
$ x='grep a'
$ echo ab | $x
ab
This doesn't—
$ x='grep a | grep b'
$ echo ab | $x
grep: |: No such file or directory
grep: grep: No such file or directory
grep: b: No such file or ...
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