Questions tagged [declare]
13 questions
49
votes
5 answers
What is "declare" in Bash?
After reading ilkkachu's answer to this question I learned on the existence of the declare (with argument -n) shell built in.
help declare brings:
Set variable values and attributes.
Declare variables and give them attributes. If no NAMEs are…
user149572
8
votes
1 answer
Does `declare -a A` create an empty array `A` in Bash?
Does declare -a A create an empty array A in bash, or does it just set an attribute in case A is assigned to later?
Consider this code:
set -u
declare -a A
echo ${#A[*]}
echo ${A[*]}
A=()
echo ${#A[*]}
echo ${A[*]}
A=(1 2)
echo ${#A[*]}
echo…
U. Windl
- 1,095
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5
votes
1 answer
Declare command and shell expansion
I stumbled by accident on the following bash behaviour, which is for me kind of unexpected.
# The following works
$ declare bar=Hello # Line 1
$ declare -p bar # Line 2
declare --…
Axel Krypton
- 324
- 2
- 12
5
votes
2 answers
What is a variable attribute?
I aim to understand the general concept of "variable attributes" hoping it will help me understand what is declare in Bash.
What is a variable attribute? Why would someone want to give an attribute to a variable? Why isn't just creating an variables…
user149572
4
votes
3 answers
Function to conditionally set a variable read-only
If I had a script which sets variables read-only to some odd values, and sets errexit because of other unsafe operations:
#!/bin/bash
set -e
declare -r NOTIFY=$(case "$OS" in (macosx) echo macos_notify ;; (linux) echo linux_notify ;; (*) echo : ;;…
cat
- 3,428
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3
votes
1 answer
Why does substituting eval with declare (for creating dynamic variables) result in an empty variable?
With bash >5, I'm trying to assign a different value to variables depending on the architecture specified in a variable. I use a function to do so. This works perfectly:
# arguments:
variable name to assign,
value for mac arch,
value for pi…
DeadBranch
- 33
- 6
3
votes
1 answer
How to read keyboard input and assign it to a local variable?
I have this very simple script:
#!/bin/bash
read local _test
echo "_test: $_test"
This is the output.
$ ./jltest.sh
sdfsdfs
_test:
I want the variable _test to be local only. Is this possible?
mrjayviper
- 1,971
- 3
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1
vote
1 answer
correct way of storing external programm and making it executable?
I downloaded the CLI Client habash for the habit/routine gameification project habatica.com.
In the fandom wiki for habash it is written that, I need to set environment variables. Additonally I want to make the program habash an ordinary…
Josomeister
- 51
- 7
1
vote
1 answer
Using cURL, jq, and declaration and for loop condition, I tried to download multiple files from a GitLab private repo, but it downloaded only one
I learned from the following sources:
curl -O: Download a file with curl on Linux / Unix command line
jq: How to urlencode data for curl command?
Multiple files and curl -J: download pdf files from using curl
Condition for loop: Shell: how to use 2…
Oo'-
- 233
- 1
- 7
0
votes
1 answer
Bash create parameter named array within function
I'm attempting to write a function that writes arrays with a name that's passed in. Given the following bash function:
function writeToArray {
local name="$1"
echo "$name"
declare -a "$name"
${name[0]}="does this work?" …
Lee
- 471
- 3
- 5
- 15
0
votes
1 answer
Cannot Display Bash Functions within FZF Preview Window
How do I get the FZF Preview Window to Display Functions from my Current Bash Environment?
I want to list my custom bash functions using FZF, and view the code of a selected function in the FZF Preview Window.
However, it does not appear that the…
user2514157
- 195
- 9
0
votes
1 answer
Reading variable from a txt file using bash
I'm new to bash.
I'm trying to write a script that will read data from a text find and declare some variables. In the example below we read from a tab delimited file "ab.txt" that looks like this:
a->AA
b->BB
Where -> denotes a tab.
I'm reading…
Adi Ro
- 101
- 3
0
votes
1 answer
Parse 3rd entry in declare result
I have this:
cd 31
/Users/alexamil/WebstormProjects/oresoftware/botch/botch-shell-overrides.sh
the above style output, is given by this command:
declare -F my_bash_func
How can I grab just the file name from that result? something…
Alexander Mills
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