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Programming, shell

IT Nursery

How to use `jq` in a shell pipeline?

I can’t seem to get jq to behave “normally” in a shell pipeline. For example: $ curl -s https://api.github.com/users/octocat/repos | jq | cat ...

May 26, 2022
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Programming, shell

IT Nursery

How to exclude this / current / dot folder from find “type d”

find . -type d can be used to find all directories below some start point. But it returns the current directory (.) too, ...

May 26, 2022
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bash, Programming

IT Nursery

Test for non-zero length string in Bash: [ -n “$var” ] or [ “$var” ]

I’ve seen Bash scripts test for a non-zero length string in two different ways. Most scripts use the -n option: #!/bin/bash # With ...

May 26, 2022
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Programming, shell

IT Nursery

How to set ssh timeout?

I’m executing a script connecting via password-less SSH on a remote host. I want to set a timeout, so that if the remote ...

May 26, 2022
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linux, Programming

IT Nursery

Add up a column of numbers at the Unix shell

Given a list of files in files.txt, I can get a list of their sizes like this: cat files.txt | xargs ls -l ...

May 26, 2022
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linux, Programming

IT Nursery

How can I quickly sum all numbers in a file?

I have a file which contains several thousand numbers, each on it’s own line: 34 42 11 6 2 99 ... I’m looking ...

May 26, 2022
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linux, Programming

IT Nursery

Is there a way to ‘uniq’ by column?

I have a .csv file like this: stack2@example.com,2009-11-27 01:05:47.893000000,example.net,127.0.0.1 overflow@example.com,2009-11-27 00:58:29.793000000,example.net,255.255.255.0 overflow@example.com,2009-11-27 00:58:29.646465785,example.net,256.255.255.0 ... I have to remove duplicate e-mails (the entire line) ...

May 26, 2022
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bash, Programming

IT Nursery

How can I remove the extension of a filename in a shell script?

What’s wrong with the following code? name="$filename | cut -f1 -d".'' As is, I get the literal string $filename | cut -f1 -d'.', ...

May 26, 2022
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Longest line in a file

I’m looking for a simple way to find the length of the longest line in a file. Ideally, it would be a simple ...

May 26, 2022
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source command not found in sh shell

I have a script that uses sh shell. I get an error in the line that uses the source command. It seems source ...

May 25, 2022
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