menu_book Course Curriculum (Bash) expand_more
Until loop
Learn until loop in Bash through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.
until loop is an atomic Bash topic inside Loops. The example uses the named construct directly so you can see its syntax, data flow, and observable behavior.
Read the code by locating the exact feature named until loop, then trace the value before and after that feature runs. This lesson is intentionally isolated from neighboring topics: changing identifiers alone would not reproduce the same behavior because the construct itself is different.
Topic-specific example
n=0
until ((n==3)); do ((n++)); done
echo "$n"
For until loop, test the boundary that makes the feature meaningful: invalid input, an empty value, a missing branch, lifecycle/cleanup, or a type/runtime constraint. Do not infer correctness only from the happy path.