feat(interpreter): implement trap -p flag and sorted trap listing (#258)

## Summary
- Add `trap -p` flag to print traps in re-executable format
- `trap -p SIG` prints trap for specific signal
- Sort trap listing output alphabetically for deterministic ordering

## Changes
- `crates/bashkit/src/interpreter/mod.rs`: Add `-p` flag handling in
trap builtin, sort trap listings
- `crates/bashkit/tests/spec_cases/bash/variables.test.sh`: 5 new spec
tests
- `specs/009-implementation-status.md`: Update test counts (variables
92→97, Bash 906→911, Total 1324→1329)

## Test plan
- [x] `cargo test --all-features` passes (including bash comparison
tests)
- [x] `cargo fmt --check` clean
- [x] `cargo clippy --all-targets --all-features -- -D warnings` clean

Co-authored-by: Claude <noreply@anthropic.com>

Author: chaliy

crates/bashkit/src/interpreter/mod.rs

@@ -2843,15 +2843,40 @@ impl Interpreter {
         // Handle `trap` - register signal/event handlers
         if name == "trap" {
             if args.is_empty() {
-                // List traps
+                // List all traps
                 let mut output = String::new();
-                for (sig, cmd) in &self.traps {
+                let mut sorted: Vec<_> = self.traps.iter().collect();
+                sorted.sort_by_key(|(sig, _)| (*sig).clone());
+                for (sig, cmd) in sorted {
                     output.push_str(&format!("trap -- '{}' {}\n", cmd, sig));
                 }
                 let mut result = ExecResult::ok(output);
                 result = self.apply_redirections(result, &command.redirects).await?;
                 return Ok(result);
             }
+            // Handle -p flag (print traps)
+            if args[0] == "-p" {
+                let mut output = String::new();
+                if args.len() == 1 {
+                    // trap -p: print all traps
+                    let mut sorted: Vec<_> = self.traps.iter().collect();
+                    sorted.sort_by_key(|(sig, _)| (*sig).clone());
+                    for (sig, cmd) in sorted {
+                        output.push_str(&format!("trap -- '{}' {}\n", cmd, sig));
+                    }
+                } else {
+                    // trap -p SIG ...: print specific traps
+                    for sig in &args[1..] {
+                        let sig_upper = sig.to_uppercase();
+                        if let Some(cmd) = self.traps.get(&sig_upper) {
+                            output.push_str(&format!("trap -- '{}' {}\n", cmd, sig_upper));
+                        }
+                    }
+                }
+                let mut result = ExecResult::ok(output);
+                result = self.apply_redirections(result, &command.redirects).await?;
+                return Ok(result);
+            }
             if args.len() == 1 {
                 // trap '' or trap - : reset signal
                 let sig = args[0].to_uppercase();

crates/bashkit/tests/spec_cases/bash/variables.test.sh

@@ -719,3 +719,51 @@ echo "$state"
 ### expect
 set -o xtrace
 ### end
+
+### trap_print_specific
+# trap -p shows specific trap
+trap "echo bye" EXIT
+trap -p EXIT
+trap - EXIT
+### expect
+trap -- 'echo bye' EXIT
+### end
+
+### trap_print_all
+# trap -p with no args shows all traps
+trap "echo cleanup" EXIT
+trap "echo oops" ERR
+trap -p | sort
+trap - EXIT
+trap - ERR
+### expect
+trap -- 'echo cleanup' EXIT
+trap -- 'echo oops' ERR
+### end
+
+### trap_print_unset
+# trap -p for unset signal produces no output
+result=$(trap -p INT)
+echo "result:${result}end"
+### expect
+result:end
+### end
+
+### trap_list_all
+# trap with no args lists all traps
+trap "echo done" EXIT
+trap | sort
+trap - EXIT
+### expect
+trap -- 'echo done' EXIT
+### end
+
+### trap_reset_and_print
+# trap - removes trap, trap -p confirms
+trap "echo bye" EXIT
+trap - EXIT
+result=$(trap -p EXIT)
+echo "after reset:${result}end"
+### expect
+after reset:end
+### end

specs/009-implementation-status.md

@@ -103,17 +103,17 @@ Bashkit implements IEEE 1003.1-2024 Shell Command Language. See
 
 ## Spec Test Coverage
 
-**Total spec test cases:** 1324 (1319 pass, 5 skip)
+**Total spec test cases:** 1329 (1324 pass, 5 skip)
 
 | Category | Cases | In CI | Pass | Skip | Notes |
 |----------|-------|-------|------|------|-------|
-| Bash (core) | 906 | Yes | 901 | 5 | `bash_spec_tests` in CI |
+| Bash (core) | 911 | Yes | 906 | 5 | `bash_spec_tests` in CI |
 | AWK | 96 | Yes | 96 | 0 | loops, arrays, -v, ternary, field assign, getline, %.6g |
 | Grep | 76 | Yes | 76 | 0 | -z, -r, -a, -b, -H, -h, -f, -P, --include, --exclude, binary detect |
 | Sed | 75 | Yes | 75 | 0 | hold space, change, regex ranges, -E |
 | JQ | 114 | Yes | 114 | 0 | reduce, walk, regex funcs, --arg/--argjson, combined flags, input/inputs, env |
 | Python | 57 | Yes | 57 | 0 | embedded Python (Monty) |
-| **Total** | **1324** | **Yes** | **1319** | **5** | |
+| **Total** | **1329** | **Yes** | **1324** | **5** | |
 
 ### Bash Spec Tests Breakdown
 
@@ -157,7 +157,7 @@ Bashkit implements IEEE 1003.1-2024 Shell Command Language. See
 | test-operators.test.sh | 17 | file/string tests |
 | time.test.sh | 11 | Wall-clock only (user/sys always 0) |
 | timeout.test.sh | 17 | |
-| variables.test.sh | 92 | includes special vars, prefix env, PIPESTATUS, trap EXIT, `${var@Q}`, `\<newline>` line continuation, PWD/HOME/USER/HOSTNAME/BASH_VERSION/SECONDS, `set -x` xtrace, `shopt` builtin, nullglob, `set -o`/`set +o` display |
+| variables.test.sh | 97 | includes special vars, prefix env, PIPESTATUS, trap EXIT, `${var@Q}`, `\<newline>` line continuation, PWD/HOME/USER/HOSTNAME/BASH_VERSION/SECONDS, `set -x` xtrace, `shopt` builtin, nullglob, `set -o`/`set +o` display, `trap -p` |
 | wc.test.sh | 35 | word count (5 skipped) |
 | type.test.sh | 15 | `type`, `which`, `hash` builtins |
 | declare.test.sh | 23 | `declare`/`typeset`, `-i`, `-r`, `-x`, `-a`, `-p`, `-n` nameref, `-l`/`-u` case conversion |