Busk at 13:32, 29 March 2023

2023-03-29T13:32:36Z

Busk: Created page with "https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable ``` n particular, one could use [ -n "${1-}" ] (that is, with an empty default valu..."

2023-03-29T13:27:40Z

Created page with "https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable ``` n particular, one could use [ -n "${1-}" ] (that is, with an empty default valu..."

New page

https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable
```
n particular, one could use [ -n "${1-}" ] (that is, with an empty default value) to see if the parameter is set and non-empty; or [ "${1+x}" = x ] to see if it's set, even if empty. –
ilkkachu
Aug 16, 2018 at 18:30
I still get unbound variable error despite using if [[ -n ${1-default} ]] –
Chaitanya Bapat
Dec 7, 2019 at 2:59
5
@ChaitanyaBapat I was still getting unbound variable as well until I used :- instead of -. So, for me at least, the ${1:-default} no loner raised the error. –
Adam Badura
Apr 9, 2020 at 11:26
As a side note, if you are trying to access an array element with an index out of range, you get the same error (with syntax ${my_array[$index]}).
```

← Older revision		Revision as of 13:32, 29 March 2023
Line 1:		Line 1:
		+
		+
		+	```
		+	if ! [ -n "${myvar-}" ]; then
		+	echo $myvar not exist
		+	fi
		+	```
		+
		+	https://tldp.org/LDP/abs/html/comparison-ops.html
		+	```
		+	-n
		+	string is not null.
		+
		+	Caution
		+	The -n test requires that the string be quoted within the test brackets. Using an unquoted string with ! -z, or even just the unquoted string alone within test brackets (see Example 7-6) normally works, however, this is an unsafe practice. Always quote a tested string. [1]
		+	```
		+
	https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable		https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable
	```		```

Bash test missing variables - Revision history

Busk at 13:32, 29 March 2023

Busk: Created page with "https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable ``` n particular, one could use [ -n "${1-}" ] (that is, with an empty default valu..."