Xlset

xlset — Excel Cell Writer

Modify cells in existing .xlsx files. Preserves formatting, formulas, and all structure it doesn't touch.

Quick Reference

# Set a single cell
xlset file.xlsx A1=42

# Set multiple cells
xlset file.xlsx A1=42 B2="hello world" C3=true

# Force type with tag (e.g., preserve leading zero)
xlset file.xlsx A1:str=07401

# Target a specific sheet
xlset file.xlsx --sheet Revenue A1=42

# Write to a new file (don't modify original)
xlset file.xlsx --output new.xlsx A1=42

# Bulk update from CSV
xlset file.xlsx --from updates.csv

# Bulk from stdin
echo "A1,42" | xlset file.xlsx --from -

Type Inference

Values are auto-detected:

• 42 → integer, 3.14 → float
• true/false → boolean
• 2024-01-15 → date
• Everything else → string

Override with tags: :str, :num, :bool, :date

CSV Format

cell,value
A1,42
B2,hello
C3:str,07401

Standard RFC 4180 quoting for values with commas: A1,"hello, world"

Exit Codes

| Code | Meaning | |------|-------------------| | 0 | Success | | 1 | Runtime error | | 2 | Invalid arguments |

Workflow

1. Use xlcat file.xlsx first to see current content
2. Use xlset to modify cells
3. Use xlcat again to verify changes

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: LouLouLibs
• Source: LouLouLibs/claude-skills
• License: MIT

Install and usage instructions live in the source repository linked above.