2025年9月11日(木) 7:02 Martin Jambon <mjam...@gmail.com>: > Description: > Expectation: I expect a syntax error in the absence of a semicolon > or a newline between the closing brackets and the then. > > Behavior with Bash 5.2.21: no error, the program behaves as if a > semicolon was present.
This is required by the POSIX standard [1-4]. Although [[ ... ]] is not technically a part of POSIX, it is a compound at the same level as (...), and (...) without a semicolon is allowed here. [1] https://lists.gnu.org/archive/html/bug-bash/2021-02/threads.html#00135 [2] https://pubs.opengroup.org/onlinepubs/9799919799/xrat/V4_xcu_chap01.html#tag_23_02_10 [3] https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html#tag_19_10_02 [4] https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html#tag_19_04 The behavior of Bash < 5.2 was simply inconsistent. $ zsh -c 'if [[ -n a ]] then echo hello; fi' hello $ ksh -c 'if [[ -n a ]] then echo hello; fi' hello $ mksh -c 'if [[ -n a ]] then echo hello; fi' hello $ yash -c 'if [[ -n a ]] then echo hello; fi' hello $ bash-5.1 -c 'if [[ -n a ]] then echo hello; fi' bash-5.1: -c: line 1: syntax error near unexpected token `then' bash-5.1: -c: line 1: `if [[ -n a ]] then echo hello; fi' $ bash-5.2 -c 'if [[ -n a ]] then echo hello; fi' hello -- Koichi
