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Questions tagged [variable-substitution]

This tag is misspelled. variable-substitution is correct. `t` is missing. This is the process of evaluating a string literal containing one or more placeholders, yielding a result in which the placeholders are replaced with their corresponding values.

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Is there an equivalent to <(process list) for variables?

I can use <(some command) in place of a file, but how can I achieve the equivalent with a variable? I'm using the paste command, which expects files as arguments, and want to use the contents of SOMEVAR as though it were a file. paste…
Matt Joiner
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Bash Variables - Define Multiple Possible Expected Values

Apologies if this has been answered previously, but I couldn't find much online. Here's what I'm trying to accomplish: if [[ "${hostname}" = (foo | bar)servername(01 | 02 | 03) ]]; then var="foobarfoo" fi With this any of the following would meet…
Tronyx
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combining tilde expansion with variable substitution in bash

Say I'm running bash as root, and I want to chown the home directory of a user ada. Say also that ada is stored in a variable called $USER (because I'm doing this from a script). When I tried the following, chown -R $USER:$USER ~$USER the shell…
Chris Middleton
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Can someone explain/give a breakdown of this shell parameter substitution? ${cfg+-f "$cfg"}

I was looking for a good workaround for keeping my .tmux.conf file consistent across systems (I have both OS X and Ubuntu and they have different techniques for copy/paste support) when I came across this comment that offered a solution:…
3cheesewheel
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Ruby variable subsitution in method call

Ruby noob here. Any help with a little issue I'm having would be appreciated. I am trying to place an array into a connection string argument which is formatted as an array. My array is as follows: hosts =…
Mr G
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how to interpolate recursive search in zsh

I want to use an environment variable in a command with recursive search. export RAILS_FILE_EXTENSIONS='(erb|feature|haml|jrxml|js|rake|rb|rxml|scss|xml|yml)' ls **/*.${RAILS_FILE_EXTENSIONS} It does not work this way. How should it look like?
Apis Mellifera
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File-transform-task in Azure DevOps release-pipeline not substituting variables

In my project, there is a Webservice.settings containing 3 variables. (Structure of Webservice.settings) I intent to set these variables with my release-pipeline (Azure DevOps). Therefore, I created a variable-group in DevOps, containig the…
Nepomuk
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Environment variables substitution in C

I have a string with the following content (UTF-8): __$FOO ${FOO} ${FOO:def} ${FOO2:-тест} And environment variable FOO with a value test. My C application should work like a GNU envsubs - replace all $FOO or ${FOO} entries with a test - nothing…
Paramtamtаm
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Azure DevOps Pipeline Json Variable Substitution - Ocelot.json

I have the following file ocelot.json and I want to change the Host object of each route configured inside the file through a variable. I want to change the localhost to the correct hostname through a variable. "Routes": [ //Parámetricas { …
camilo-cajamarca
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Is there a parameter substitution syntax for file or directory existence?

I would like to use parameter substitution to compute a path based on a variable being defined a first default directory to be used if it exists a file inside the $HOME directory to be used if neither of 1 or 2 are available. The variable (#1) and…
iconoclast
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Variable Substiution in sed executing via python

Below is my sed command: sed "s/N([0-9]*)/sum('\1')/g" old.txt > new.txt works fine in bash terminal But below python code doesnot execute :- file1=old.txt file2.new.txt sed_cmd = 'sed "s/0x\([0-9]*\)/sum('\1')/g" %s > %s' %(file1,file2) I get…
HDev007
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Simple configuration files template processor that preserves bash-style variables

I have to introduce some templating over text configuration files (yaml, xml, json) that already contain bash-like syntax variables. I need to preserve existing bash-like variables untouched but substitute my ones. List is dynamic, variables should…
Roman Nikitchenko
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Transformation / Substitution of configuration files in AWS CodePipeline

Finally getting into AWS after several years in Azure. I have a CodePipeline set-up for a dotnet core lambda function. Traditionally I have set-up build pipelines and then transformed the configuration files for each release stage. Azure has an…
JDBennett
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Substitute variable as an input from the STDOUT of a console application

In our release pipeline, we have a console app that performs a function which generates an encryption key and outputs it to STDOUT. We need to be able to use this value in a variable during deployment (updating a configuration file with the results…
Dean Selley
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Separating yaml files and passing in variables

Is there any way to separate a YAML file and pass in variables to sub files? For Example: Parent yaml file: Fn::Merge: - !Include /templates/first.yaml, variables: {env: staging} - !Include /templates/second.yaml, variables: {env:…
John David
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