diff options
author | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-04-15 17:37:46 -0400 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-04-15 17:37:46 -0400 |
commit | bb819d5ef6c6dc68da524de07991eae2a2c3a3af (patch) | |
tree | fb5349192696db11086dc85820b0bf4b4e5d6c95 /HACKING/code-quality.md | |
parent | 7bd29f4570869e1db2992e337f86e93f1cfa43e7 (diff) |
Use a better technique for dealing with empty arrays when `set -u`.
https://news.ycombinator.com/item?id=11497636
Diffstat (limited to 'HACKING/code-quality.md')
-rw-r--r-- | HACKING/code-quality.md | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/HACKING/code-quality.md b/HACKING/code-quality.md index a520ce5..8efd561 100644 --- a/HACKING/code-quality.md +++ b/HACKING/code-quality.md @@ -49,7 +49,8 @@ Use `set -u` if you can; it makes using an unset variable an error. - If a variable not being set is valid (perhaps a configuration option), use `${var:-}` when accessing it to suppress the error. - An empty array counts as unset, so if you have an array that may be - empty, use `set +u` before accessing it. + empty, use `${var+"${var[@]}"}` (don't put quotes around the outer + pair of braces) to only access it if it's non-empty. - The reason for this is that a normal string variable is basically an array with length=1; an unset variable looks like an array with length=0. Weird stuff. |