bashHow to check if variable is set or unset
if [ -z ${variable+x} ]; then echo "\$variable is not set"; else echo "\$variable is set"; fictrl + cvariablename of varible we're checking | echo "\$variable is not set"will execute if variable is not set |
echo "\$variable is set"will execute if variable is set, even if it's empty ( | |
More of Bash
- Binet's Formula in bash
- How to check if a string starts with a specific value
- How to assign an output of a command to a variable
- Quickly create big file
- How to extract file extension
- How to extract file name
- Urlencode string in bash
- Check if a string contains a substring
- How to get time in "HH:II:SS" (hour:minute:second) format
See more codes...