---
name: unicode-safe-file-writing-44bc8fcdd315
description: How to reliably write files containing multi-byte Unicode (emoji, special symbols) when write_file fails with 'unknown error' by falling back to run_shell with a heredoc.
---

# Unicode-Safe File Writing

## Problem

The `write_file` tool may fail with `'unknown error'` when the file content
contains multi-byte Unicode characters such as:

- Emoji (e.g. `🚀`, `✅`, `❌`)
- Special typographic symbols (e.g. `→`, `•`, `—`, `©`)
- Non-ASCII characters outside the Latin-1 range

This is a known encoding limitation of `write_file`.

## Solution

Fall back to `run_shell` and write the file using a **shell heredoc**
(`cat > file << 'EOF' ... EOF`). The single-quoted delimiter `'EOF'`
prevents the shell from interpreting any special characters inside the
block.

---

## Step-by-Step Recovery

### Step 1 — Detect the failure

If `write_file` returns an error such as:

```
Error: unknown error
```

and the content contains non-ASCII characters, assume a Unicode encoding
issue and proceed to the heredoc fallback.

### Step 2 — Strip or replace problematic characters (if needed)

Before embedding content in the heredoc, decide whether to:

- **Keep** the characters as-is (works if the shell/terminal is UTF-8 aware)
- **Replace** emoji/symbols with ASCII equivalents (safest, most portable)
- **Remove** them entirely

Common replacements:

| Original | Replacement |
|----------|-------------|
| `✅`     | `[OK]`      |
| `❌`     | `[ERROR]`   |
| `🚀`     | `[START]`   |
| `→`      | `->`        |
| `•`      | `-`         |
| `—`      | `--`        |

### Step 3 — Write the file via heredoc

Use `run_shell` with the following pattern:

```bash
cat > path/to/file.ext << 'EOF'
...file content here (with Unicode stripped/replaced if needed)...
EOF
```

**Key details:**
- Use `'EOF'` (single-quoted) as the heredoc delimiter — this disables all
  shell variable expansion and special character interpretation inside the block.
- Do **not** indent the closing `EOF` (it must start at column 0).
- For deeply nested content, choose a delimiter that cannot appear in the
  content itself (e.g. `'HEREDOC_END'`, `'FILEEND'`).

---

## Example

### Failing call

```python
write_file(
    path="src/components/StatusPanel.ts",
    content="// Status icons\nconst icons = { ok: '✅', err: '❌', run: '🚀' };\n"
)
# → Error: unknown error
```

### Recovery via heredoc

```bash
cat > src/components/StatusPanel.ts << 'EOF'
// Status icons
const icons = { ok: '[OK]', err: '[ERROR]', run: '[START]' };
EOF
```

Or, if UTF-8 output is acceptable in the environment:

```bash
cat > src/components/StatusPanel.ts << 'EOF'
// Status icons
const icons = { ok: '✅', err: '❌', run: '🚀' };
EOF
```

---

## Multi-File Scenario

When writing several files and one fails, write the others with `write_file`
as normal and apply the heredoc fallback only to the failing file(s):

```bash
# Write multiple files that contain Unicode
cat > src/utils/icons.ts << 'EOF'
export const ICONS = {
  success: '[OK]',
  failure: '[FAIL]',
  pending: '[...]',
};
EOF

cat > src/utils/labels.ts << 'EOF'
export const LABELS = {
  title: 'Dashboard',
  subtitle: 'Real-time status',
};
EOF
```

---

## Important Notes

1. **Always prefer `write_file` first** — only fall back to the heredoc
   approach when `write_file` fails.
2. **Verify after writing** — use `run_shell` with `cat path/to/file` or
   `head -5 path/to/file` to confirm the content was written correctly.
3. **Directory creation** — `write_file` auto-creates parent directories;
   the heredoc approach does not. Pre-create directories with
   `mkdir -p path/to/dir` if needed.
4. **Large files** — heredocs work well for files of any practical size;
   there is no meaningful shell limit.
5. **Escaping backslashes** — inside a single-quoted heredoc, backslashes
   are treated literally (no escaping needed), which is usually desirable.

---
Source attribution: AG064
Original project: https://github.com/AG064/OpenSpace/blob/ff671ef61ed6587c49bd54c81cdc751c0b99e363/showcase/skills/unicode-safe-file-writing/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.

## Upstream license notice

MIT License

Copyright (c) 2026 ✨Data Intelligence Lab@HKU✨

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Dave AI resource metadata

Creator / publisher: AG064
Original project: https://github.com/AG064/OpenSpace/blob/ff671ef61ed6587c49bd54c81cdc751c0b99e363/showcase/skills/unicode-safe-file-writing/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering
Roles: Backend Developer, DevOps / SRE, Full-Stack Developer
Specialties: Backend
Tools: Run_Shell
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 68fcc3c9e8131418398e9450ced01f620eb77196da384a27ca3838ff9ac841da