Command Line Interface

# Generate TOC and print to stdout
markdown-toc <input-file>

# Read from stdin
echo "# Title\n## Section" | markdown-toc -

# Generate TOC and inject into file  
markdown-toc -i <input-file>

# Basic TOC generation
markdown-toc README.md

# Process from stdin
cat document.md | markdown-toc -

# Inject TOC into file between <!-- toc --> markers
markdown-toc -i README.md

markdown-toc [options] <input>

Options:
  -i                    Edit the input file directly, injecting TOC at <!-- toc -->
  --json                Print the TOC in JSON format  
  --append <string>     Append a string to the end of the TOC
  --bullets <chars>     Bullets to use for items in the generated TOC
  --maxdepth <number>   Use headings whose depth is at most maxdepth (default: 6)
  --no-firsth1          Include the first h1-level heading in a file
  --no-stripHeadingTags Do not strip extraneous HTML tags from heading text

Arguments:
  <input>               The Markdown file to parse for TOC, or "-" for stdin

# Limit depth and customize bullets
markdown-toc --maxdepth 3 --bullets "*" README.md

# Multiple bullet types for different levels
markdown-toc --bullets "*" --bullets "-" --bullets "+" README.md

# Include first H1 and append footer
markdown-toc --no-firsth1 --append "_(Generated by markdown-toc)_" README.md

# Output JSON format
markdown-toc --json README.md

# Combine multiple options
markdown-toc -i --maxdepth 2 --bullets "-" --append "\n\n*Auto-generated*" docs/API.md

# Before: README.md contains <!-- toc --> marker
markdown-toc -i README.md
# After: README.md has TOC injected at marker location

# Process multiple files (using shell globbing)
for file in docs/*.md; do
  markdown-toc -i --maxdepth 3 "$file"
done

markdown-toc --json README.md

[
  {
    "content": "Introduction", 
    "slug": "introduction",
    "lvl": 1,
    "i": 0,
    "seen": 0
  },
  {
    "content": "Getting Started",
    "slug": "getting-started", 
    "lvl": 2,
    "i": 1,
    "seen": 0
  }
]

# Generate TOC from stdin
echo -e "# Title\n## Section\n### Subsection" | markdown-toc -

# Pipeline processing
curl -s https://raw.githubusercontent.com/user/repo/main/README.md | markdown-toc -

# Process with options
cat document.md | markdown-toc --maxdepth 2 --bullets "•" -

# Invalid usage examples that trigger errors:

# Missing input file
markdown-toc
# Error: Usage: markdown-toc [options] <input>

# Using -i with stdin  
echo "# Title" | markdown-toc -i -
# Error: markdown-toc: you cannot use -i with "-" (stdin) for input

# Using -i with --json
markdown-toc -i --json README.md  
# Error: markdown-toc: you cannot use both --json and -i

# File not found
markdown-toc nonexistent.md
# Error: ENOENT: no such file or directory

# In package.json scripts
{
  "scripts": {
    "docs:toc": "markdown-toc -i README.md",
    "docs:build": "markdown-toc -i --maxdepth 3 docs/*.md"
  }
}

# In Makefile
docs-toc:
	find docs -name "*.md" -exec markdown-toc -i --maxdepth 2 {} \;

# In CI/CD pipeline  
script:
  - markdown-toc --json README.md > toc.json
  - markdown-toc -i --maxdepth 3 --append "_(Updated: $(date))_" docs/API.md

# Process all markdown files in directory
find . -name "*.md" -not -path "./node_modules/*" | \
  xargs -I {} markdown-toc -i --maxdepth 3 --bullets "-" {}

# Generate TOC for all files and save outputs
for file in docs/*.md; do
  basename=$(basename "$file" .md)
  markdown-toc "$file" > "toc-${basename}.md"
done

# Generate detailed TOC with custom formatting
markdown-toc \
  --maxdepth 4 \
  --bullets "▶" \
  --append "\n\n---\n*Table of contents generated on $(date)*" \
  --no-stripHeadingTags \
  documentation.md

# Process with custom bullets for each level
markdown-toc \
  --bullets "•" \
  --bullets "◦" \
  --bullets "▪" \
  --bullets "▫" \
  complex-document.md

# Success
markdown-toc README.md
echo $? # Output: 0

# File not found
markdown-toc missing.md
echo $? # Output: 1

# Invalid arguments  
markdown-toc -i --json README.md
echo $? # Output: 1