---
name: safe-script-execution-3d0de8271e73
description: Fallback workflow for code execution when automated tools fail, using shell heredoc with verification
---

# Safe Script Execution Fallback

## When to Use This Skill

Use this pattern when `execute_code_sandbox` or `shell_agent` repeatedly fails to produce expected outputs. This manual fallback provides explicit control over script creation and execution with built-in verification.

## Step-by-Step Instructions

### Step 1: Verify Working Directory

Before creating any scripts, confirm your current location and permissions:

```bash
pwd
ls -la
```

Document the absolute path. All subsequent file operations should use explicit paths from this point.

### Step 2: Create Script via Heredoc

Use shell heredoc syntax to create scripts. This avoids issues with multi-line string escaping:

```bash
cat > /full/path/to/script.py << 'HEREDOC_END'
#!/usr/bin/env python3
# Your script content here
# Single quotes around delimiter prevent variable expansion
print("Hello from script")
HEREDOC_END
```

**Key escaping rules:**
- Use single quotes around heredoc delimiter (`'EOF'`) to prevent shell variable expansion
- If script contains the delimiter string, choose a different unique delimiter
- For bash scripts containing special characters, escape `$`, backticks, and `!`

### Step 3: Make Executable and Run with Explicit Path

```bash
chmod +x /full/path/to/script.py
/full/path/to/script.py
```

Always use the full absolute path, never rely on `.` or relative paths.

### Step 4: Verify Output

Confirm files were created and inspect their properties:

```bash
# Check file exists with size
ls -lh /full/path/to/output.file

# For PDFs, inspect metadata
pdfinfo /full/path/to/output.pdf 2>/dev/null || file /full/path/to/output.pdf

# For Word docs, check file type
file /full/path/to/output.docx
```

### Step 5: Error Handling

If execution fails:
1. Check script syntax: `python3 -m py_compile /path/to/script.py`
2. Check permissions: `ls -l /path/to/script.py`
3. Check available disk space: `df -h .`
4. Review stderr output carefully

## Example: PDF Generation Fallback

```bash
# Step 1: Verify directory
pwd
ls -la

# Step 2: Create Python script
cat > /workspace/generate_pdf.py << 'SCRIPT_END'
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

c = canvas.Canvas("/workspace/output.pdf", pagesize=letter)
c.drawString(100, 750, "Generated PDF")
c.save()
SCRIPT_END

# Step 3: Execute
chmod +x /workspace/generate_pdf.py
python3 /workspace/generate_pdf.py

# Step 4: Verify
ls -lh /workspace/output.pdf
pdfinfo /workspace/output.pdf 2>/dev/null || echo "PDF created, pdfinfo unavailable"
```

## Anti-Patterns to Avoid

- ❌ Don't use relative paths like `./script.py` - always use absolute paths
- ❌ Don't rely on unquoted heredoc delimiters if script contains variables
- ❌ Don't skip verification steps - always confirm output exists and has expected size
- ❌ Don't assume working directory - always `pwd` first

## Troubleshooting Checklist

- [ ] Working directory confirmed with `pwd`
- [ ] Script file exists after heredoc creation (`ls -l`)
- [ ] Script has execute permissions (`chmod +x`)
- [ ] Output file exists with non-zero size (`ls -lh`)
- [ ] File type verified (`file` command or type-specific inspection)

---
Source attribution: AG064
Original project: https://github.com/AG064/OpenSpace/blob/ff671ef61ed6587c49bd54c81cdc751c0b99e363/gdpval_bench/skills/safe-script-execution/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## 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.



# Mega AI Hub resource metadata

Creator / publisher: AG064
Original project: https://github.com/AG064/OpenSpace/blob/ff671ef61ed6587c49bd54c81cdc751c0b99e363/gdpval_bench/skills/safe-script-execution/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering
Roles: Backend Developer, DevOps / SRE, QA / Test Engineer
Specialties: Backend, DevOps
Tools: Shell
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 735e141d033d74dee059db2c5bc59056b2b080aeff09590ceae5ce03e7076aec