Timeline for Difference between parentheses and braces in terminal?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| S Jun 21, 2022 at 14:51 | history | suggested | Amin.A | CC BY-SA 4.0 | Added a small example to explain the meaning behind "side effect". |
| Jun 17, 2022 at 18:34 | review | Suggested edits | |||
| S Jun 21, 2022 at 14:51 | |||||
| Mar 4, 2016 at 17:36 | comment | added | schily | See my new paragraph about side-effects. In your example, there is no visible difference. | |
| Mar 4, 2016 at 17:36 | vote | accept | Nelske | ||
| Mar 4, 2016 at 17:35 | history | edited | schily | CC BY-SA 3.0 | side-effects added |
| Mar 4, 2016 at 17:32 | comment | added | Nelske | So if I understand correctly, the only difference is that: parentheses use a subshell and braces don't? And the output stays the same, regardless of the subshell (in this case). Thankyou, this helped! | |
| Mar 4, 2016 at 17:22 | history | edited | schily | CC BY-SA 3.0 | added 634 characters in body |
| Mar 4, 2016 at 17:20 | comment | added | Stéphane Chazelas | Yes, you'll notice that the POSIX spec is careful to talk only of subshell environment with no implication that it may involve a child process. And with many shells that implement subshells using a child process, (a;b) will not spawn more processes than {a;b;} (if b is not a builtin nor function nor compound command and there's no local trap) as b will be executed in that child subshell process. | |
| Mar 4, 2016 at 17:14 | comment | added | schily | Well parentheses grant the commands to be in a subshell, with braces, it still may happen ;-) but ksh93 does not even create a real subshell for parentheses, but rather emulates the effects of a subshell by using a temporary new copy of parameters. | |
| Mar 4, 2016 at 17:11 | comment | added | Stéphane Chazelas | (I wouldn't have bothered mentioning it but since you're maintaining a Bourne shell ;)), ...not in a subshell, except for the Bourne shell that runs compound commands in subshells when redirected. | |
| Mar 4, 2016 at 17:07 | history | answered | schily | CC BY-SA 3.0 |