Timeline for Testing if shell variable is set
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 9, 2023 at 8:19 | comment | added | Edgar Magallon | @ilkkachu And I just realized that the relevant text is above the examples haha :). Also, thanks for the link, it's more useful and handy! | |
| May 9, 2023 at 8:14 | history | edited | ilkkachu | CC BY-SA 4.0 | added 2 characters in body |
| May 9, 2023 at 7:54 | history | edited | DaG | CC BY-SA 4.0 | added 188 characters in body |
| May 9, 2023 at 7:45 | comment | added | DaG | Sorry for misunderstanding the question. I thought that you want to test if variable is set not if it's empty... | |
| May 9, 2023 at 7:39 | comment | added | ilkkachu | @EdgarMagallon, yep, one often sees just the ones with the colon. Sadly, Bash's manual, hides the distinction within the text, it says "Omitting the colon results in a test only for a parameter that is unset. [...] if the colon is omitted, the operator tests only for existence." but all the examples are with the colon. The POSIX text has a nice table of all the variants, though, so at least here, it's a better read. | |
| May 9, 2023 at 7:00 | comment | added | Edgar Magallon | @ilkkachu oh, that's true! my bad. I really thought they missed the colons, I had no idea about that until I tried what you said. Thanks! | |
| May 9, 2023 at 5:19 | history | edited | ilkkachu | CC BY-SA 4.0 | deleted 16 characters in body |
| May 9, 2023 at 5:18 | comment | added | ilkkachu | @EdgarMagallon, oh, I guess my comment above is for you. | |
| May 9, 2023 at 0:52 | comment | added | ilkkachu | With ${var:+x}, you get x only if the variable is set and non-empty. Without the colon ${var+x}, you get x is it's set to any value. Same with ${var:?error}, it'd also trigger for a set but empty value, not just an unset one. | |
| May 9, 2023 at 0:47 | history | edited | Edgar Magallon | CC BY-SA 4.0 | format, missing ":", remove unncesary/duplicated example: "${var:?error_message}" |
| May 9, 2023 at 0:41 | history | edited | DaG | CC BY-SA 4.0 | deleted 10 characters in body |
| May 9, 2023 at 0:36 | history | undeleted | DaG | ||
| May 9, 2023 at 0:35 | history | deleted | DaG | via Vote | |
| May 9, 2023 at 0:34 | history | answered | DaG | CC BY-SA 4.0 |