Shell echo command should support -n flag

[LSantha]

Summary

Add a -n flag to the shell echo command to suppress the trailing newline, matching common shell behavior.

Problem

Scripts that build output incrementally (prompts, progress lines) cannot avoid the trailing newline today. Workarounds via printf do not exist in this shell.

Proposal / Spec

• echo -n <args> prints args separated by spaces with no trailing newline.
• echo <args> behavior unchanged.
• Touch zone: shell builtin echo command implementation plus its help text.

Requirements

• Functional: -n must be first-arg only; echo -n alone prints nothing and exits zero.
• Non-functional: Java 1.6 only, US-ASCII, existing formatter, no new dependencies.
• Out of scope: escape-sequence interpretation (no -e flag in this issue).

Acceptance Criteria

• echo -n hello outputs hello with no newline.
• echo hello output byte-identical to before.
• Help text documents -n.

How to Test

• Unit: hosting shell command test module if present, else boot QEMU and compare shell output bytes.
• New tests added for the -n case.

Alternatives Considered

• printf builtin: larger scope, separate issue.
• No change: leaves scripts without the capability.

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❌ Ticket Runner Status

Field	Value
Phase	FAILED
Turn	0/3
Retries	3/3
PR	-
Started	2026-09-20T14:15:56.889Z

Triage Addendum (auto, 2026-09-20)

• Area / Kind: area/shell + kind/feature
• Blast radius: L2 package (org.jnode.shell.bjorne, new EchoBuiltin plus registration, no plugin export)
• Expected scope: 1 new file plus registration plus help text, ~50 lines; no ASM, boot, or API changes
• Test path: cd shell && ant test, plus new builtin test cases
• Merge signal: human-review (feature kind; small scope but needs human scope decision)
• Gaps: none
• Full report: ## Triage comment below.

[LSantha]

/oc triage issue #660

Triage run ONLY. Load the jnode-triage-issue skill and obey it. Output is exactly one ## Triage comment plus kind/area label edits. FORBIDDEN in this run: git checkout -b, git push, gh pr create, any branch, any PR. Audit kind/area labels (correct mislabels), assess repro-sufficiency, estimate blast radius, post one ## Triage comment (clear shape when actionable, vague shape with the needs-info literals only when human input is truly required).

[LSantha]

Triage

• Area: area/shell (shell builtin echo command implementation, source location: shell/src/shell/org/jnode/shell/bjorne/ based on existing builtins like SetBuiltin.java)
• Kind: kind/feature (adds new behavior with problem + proposal + acceptance criteria + test path)
• Repro: The issue clearly describes the current behavior (echo hello always prints with newline) and the desired behavior (echo -n hello should print without newline)
• Blast radius: L2 package (org.jnode.shell.bjorne, ~3 classes for the new EchoBuiltin + modifications to BjorneInterpreter.java to register it). No plugin exports or public API changes. Safe to implement.
• Expected scope: Create new EchoBuiltin.java class (extend BjorneBuiltin), add -n flag syntax via FlagArgument and ArgumentSyntax, update BjorneInterpreter.BUILTINS to register "echo", modify help text. ~50 lines. No changes to ASM, boot path, or public API.
• Test path: Host-JVM: run unit tests in shell module with JUnit (cd shell && ant test). New test script in shell/src/test/org/jnode/test/shell/bjorne/bjorne-builtin-tests.xml with tests for -n and default behavior.
• Merge signal: safe (small expected scope, no boot path, no public API changes, existing test path works)
• Gaps: None (implementation follows existing builtin patterns: ReadBuiltin, ExitBuiltin)
• Suggested next: Implement EchoBuiltin.java and add tests
• Split proposal: None (focused change)
• Labels applied: kind/feature, area/shell

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[LSantha]

/oc triage issue #660

[LSantha]

I can't edit source files during triage mode. Here's what needs to be implemented to add -n flag support to the shell echo command:

Required Changes

1. Create EchoBuiltin.java in shell/src/shell/org/jnode/shell/bjorne/:

• Follow BjorneBuiltin pattern (like ReadBuiltin.java or ExitBuiltin.java)
• Use FlagArgument for the -n flag
• Print arguments with spaces, add newline only if flag not set
• Should work with echo -n alone (prints nothing, exits 0)

2. Register in BjorneInterpreter.java:

• Add "echo", EchoBuiltin.FACTORY to the BUILTINS static map (lines 127-150)

3. Add tests to bjorne-builtin-tests.xml:

• Test echo -n hello outputs hello without newline
• Test echo hello behaves exactly as before
• Test echo -n prints nothing with no newline

Files to modify:

• shell/src/shell/org/jnode/shell/bjorne/EchoBuiltin.java (NEW)
• shell/src/shell/org/jnode/shell/bjorne/BjorneInterpreter.java:135-150
• shell/src/test/org/jnode/test/shell/bjorne/bjorne-builtin-tests.xml

The implementation follows the existing FlagArgument pattern used by other builtins like set -x and read -r.

opencode session  |  github run

[LSantha]

/oc Please proceed with this task.

[LSantha]

Created PR #661

opencode session  |  github run

[LSantha]

/oc Please proceed with this task.

[LSantha]

Created PR #662

opencode session  |  github run

[LSantha]

/oc Please proceed with this task.

[LSantha]

❌ Ticket runner: phase DEV failed after 3 retries.