[BUG] head -N with multiple files rewrites to invalid `rtk read file1 file2 ... --max-lines N`

[pjcau]

Summary

rtk rewrite turns head -N file1 file2 ... into rtk read file1 file2 ... --max-lines N, but rtk read only accepts a single <FILE> argument. When invoked with multiple files, rtk read falls through to the system read command (/usr/bin/read on macOS, which is a POSIX wrapper around the shell builtin), which interprets the first filename as a variable name and fails with "not a valid identifier".

Same class of bug as #989 (cat multi-file, fixed) and #1108 (tail -N).

Repro

$ rtk --version
rtk 0.37.0   # also confirmed on 0.31.0

$ rtk rewrite "head -3 /tmp/a /tmp/b /tmp/c"
rtk read /tmp/a /tmp/b /tmp/c --max-lines 3

$ rtk read /tmp/a /tmp/b /tmp/c --max-lines 3
/usr/bin/read: line 4: read: `/tmp/a': not a valid identifier
$ echo $?
0   # silent failure — exit 0 despite error

Real-world Claude Code failure:

$ head -5 .claude/skills/generate/SKILL.md .claude/skills/enclosure-design/SKILL.md
Exit code 1
/usr/bin/read: line 4: read: `.claude/skills/generate/SKILL.md': not a valid identifier

Environment

• OS: macOS (Darwin 25.2.0)
• rtk: 0.37.0 (also 0.31.0)
• Claude Code hook v2 (auto-patched via rtk init -g --auto-patch)

Expected

Either:

1. rtk rewrite returns exit 1 (no rewrite) when head -N has >1 file argument, so the shell runs native head — consistent with the cat fix in Cat multiple files result in an error #989.
2. rtk read natively supports multiple files.

Workaround

Use rtk proxy head -N file1 file2 ... to bypass the rewrite, or use editor/IDE file-read tools that don't go through Bash.

Related

• Cat multiple files result in an error #989 Cat multiple files result in an error (closed, same class)
• Claude Code hook: tail -N rewrite produces invalid rtk read -N (should be -n N) #1108 Claude Code hook: `tail -N` rewrite produces invalid `rtk read -N` (same class)

[pszymkowiak]

[w] wshm · Automated triage by AI

🔍 Automated Triage

🐛 Category	bug
🟡 Priority	medium
🎯 Confidence	95%

Summary

The rewrite engine incorrectly translates multi-file head -N into a single-file rtk read command; should fall back to native head for multiple files. PR #1371 already in progress.

This looks like a simple fix. Only repo maintainers can trigger auto-fix.

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Triaged automatically by wshm · This is an automated analysis, not a human review.