Bash: how to properly accept user input?

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I couldn't find an example online but I'm sure I've seen shell coders use $1:-- to accept user input. Here's an example:

#!/bin/bash

var="$1:--"
echo "$var"

Then, run it:

$ ./test.sh "this is a test"

My question is: how is using "$1:--" to accept user input different from "$1"?

asked 12 mins ago

user318062

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up vote
0
down vote

favorite

I couldn't find an example online but I'm sure I've seen shell coders use $1:-- to accept user input. Here's an example:

#!/bin/bash

var="$1:--"
echo "$var"

Then, run it:

$ ./test.sh "this is a test"

My question is: how is using "$1:--" to accept user input different from "$1"?

asked 12 mins ago

user318062

New contributor

add a commentÂ |Â

up vote
0
down vote

favorite

I couldn't find an example online but I'm sure I've seen shell coders use $1:-- to accept user input. Here's an example:

#!/bin/bash

var="$1:--"
echo "$var"

Then, run it:

$ ./test.sh "this is a test"

My question is: how is using "$1:--" to accept user input different from "$1"?

asked 12 mins ago

user318062

New contributor

I couldn't find an example online but I'm sure I've seen shell coders use $1:-- to accept user input. Here's an example:

#!/bin/bash

var="$1:--"
echo "$var"

Then, run it:

$ ./test.sh "this is a test"

My question is: how is using "$1:--" to accept user input different from "$1"?

bash shell-script shell command-line input

asked 12 mins ago

user318062

New contributor

asked 12 mins ago

user318062

New contributor

asked 12 mins ago

user318062

New contributor

asked 12 mins ago

user318062

asked 12 mins ago

user318062

New contributor

user318062 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

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