expr: Escape anchor characters within pattern#7842
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sylvestre merged 16 commits intouutils:mainfrom Apr 27, 2025
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The anchor characters `^` and `$` are not considered special characters by `expr` unless they are used as expected on the start or end of the pattern.
It is not escaped by GNU `expr` either
sylvestre
reviewed
Apr 25, 2025
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GNU testsuite comparison: |
The `rust-onig` bug still exists but parsing carets is fixed within uutils' `expr`
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GNU testsuite comparison: |
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GNU testsuite comparison: |
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Pull Request Overview
This PR improves the character escaping logic in regexp pattern definitions and reactivates/upgrades tests to verify the new behavior.
- Core pattern extraction now removes any extra leading '^' and escapes internal '^' characters.
- Tests have been updated to cover various scenarios including patterns starting with '^', '*' and multiple '^' occurrences.
Reviewed Changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| tests/by-util/test_expr.rs | Updated tests to reflect the new escaping behavior for patterns. |
| src/uu/expr/src/syntax_tree.rs | Reworked regex string building logic to correctly escape internal '^' characters. |
Comments suppressed due to low confidence (2)
src/uu/expr/src/syntax_tree.rs:170
- [nitpick] Consider renaming the variable 'prev' to a more descriptive name like 'previous_char' to improve code clarity.
let mut prev = first.unwrap_or_default();
tests/by-util/test_expr.rs:293
- [nitpick] Consider adding an inline comment that explains the expected output for patterns starting with '^' to clarify the transformation rules for future maintainers.
new_ucmd!().args(&["^abc", ":", "^^abc"])
Contributor
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and it passes: |
nickorlow
pushed a commit
to nickorlow/coreutils
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this pull request
Jul 17, 2025
* expr: Escape anchor characters within the core pattern The anchor characters `^` and `$` are not considered special characters by `expr` unless they are used as expected on the start or end of the pattern.
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Escape the regexp start of string anchor characters '^' within pattern definitions. Only keep the start anchor as is if it is at the beginning of the user input pattern.
Changes
Testing
fixes #7663