install-claudesidian-command - SKILL.md Agent Skill

name: install-claudesidian-command description: Install claudesidian shell command to launch Claude Code from anywhere. Use when the user wants to install a shell alias/launcher for their vault, or asks to set up the claudesidian command.

Install Claudesidian Command

Creates a shell alias/function that allows you to run claudesidian from anywhere to open your vault in Claude Code.

Task

Install a shell command that:

Changes to your claudesidian vault directory
Launches Claude Code
Works from any directory in your terminal

Similar to having a quick launcher for your vault.

Process

1. Detect Current Setup

Check which shell the user is using (bash/zsh/fish)
Find the current working directory (vault path)
Determine the appropriate config file

2. Create the Command

The command will be an alias that:

Changes to the vault directory: cd /path/to/your/vault
Tries to resume existing session: claude --resume 2>/dev/null
Falls back to new session if no existing one: || claude
All in one command with properly escaped path: (cd "/path/to/vault" && (claude --resume 2>/dev/null || claude))

Important: The path must be properly escaped to handle spaces and special characters.

This automatically enters resume mode if there's an existing session, or starts a new one if not.

3. Install to Shell Config

Add the alias to the appropriate config file:

Bash: ~/.bashrc or ~/.bash_profile
Zsh: ~/.zshrc
Fish: ~/.config/fish/config.fish

4. Verify Installation

Show the added line
Remind user to reload their shell or source the config
Provide test command

Shell Detection

Detects the user's default shell, with support for command-line override:

# Check if shell specified as argument (/install-claudesidian-command zsh)
if [ -n "$1" ]; then
  # User provided shell type as argument
  SHELL_TYPE="$1"
else
  # Auto-detect from $SHELL (user's default shell, not current shell)
  SHELL_TYPE=$(basename "$SHELL")
fi

# Validate shell type and set appropriate config file
case "$SHELL_TYPE" in
  zsh)
    CONFIG_FILE="$HOME/.zshrc"
    ;;
  bash)
    # Prefer .bashrc on Linux, .bash_profile on macOS
    if [ -f "$HOME/.bashrc" ]; then
      CONFIG_FILE="$HOME/.bashrc"
    else
      CONFIG_FILE="$HOME/.bash_profile"
    fi
    ;;
  fish)
    CONFIG_FILE="$HOME/.config/fish/config.fish"
    ;;
  *)
    echo "❌ Unsupported shell: $SHELL_TYPE"
    echo "   Supported shells: bash, zsh, fish"
    echo "   Usage: /install-claudesidian-command [bash|zsh|fish]"
    exit 1
    ;;
esac

echo "🐚 Installing for: $SHELL_TYPE"
echo "📝 Config file: $CONFIG_FILE"

Key improvements:

Uses $SHELL to detect default shell (not $ZSH_VERSION/$BASH_VERSION which detect current session)
Supports command-line argument to override auto-detection
Shows detected shell and config file for transparency
Validates shell type and provides clear error message for unsupported shells

Installation Steps

Detect shell: Use argument if provided, otherwise auto-detect from $SHELL
Get vault path: Use pwd to get current directory

Escape the path: Properly escape quotes and special characters for shell safety

# Escape backslashes FIRST (so we don't double-escape ones we add later)
ESCAPED_PATH="${VAULT_PATH//\\/\\\\}"
# Then escape double quotes
ESCAPED_PATH="${ESCAPED_PATH//\"/\\\"}"

Check if already installed: Search config file for existing claudesidian alias/function

# Check for existing alias/function
if grep -q "alias claudesidian\|function claudesidian" "$CONFIG_FILE"; then
  echo "⚠️  Found existing claudesidian command:"
  grep -A 3 "claudesidian" "$CONFIG_FILE"
  echo ""
  read -p "Replace it? (yes/no): " replace_answer
  if [[ ! "$replace_answer" =~ ^[Yy] ]]; then
    echo "Installation cancelled. Existing command preserved."
    exit 0
  fi
  # Mark for replacement (will remove before adding new one)
  REPLACING=true
fi

Get user confirmation: Show what will be added and get final confirmation

Create backup: Only if proceeding with modification

# Create backup with timestamp
BACKUP_FILE="$CONFIG_FILE.backup-$(date +%Y%m%d-%H%M%S)"
cp "$CONFIG_FILE" "$BACKUP_FILE"
echo "💾 Backup created: $BACKUP_FILE"

Build the safe alias/function command: Use the escaped path from step 3

# CRITICAL: Use $ESCAPED_PATH in the command (not raw $VAULT_PATH)
if [ "$SHELL_TYPE" = "fish" ]; then
  # Fish uses function syntax, not alias
  COMMAND_TEXT="function claudesidian
 cd \"$ESCAPED_PATH\" && (claude --resume 2>/dev/null; or claude)
 cd -
end"
else
  # Bash/Zsh use alias syntax
  # IMPORTANT: Use double quotes around $ESCAPED_PATH to preserve escaping
  COMMAND_TEXT="alias claudesidian='(cd \"$ESCAPED_PATH\" && (claude --resume 2>/dev/null || claude))'"
fi

Remove old command if replacing:
```
if [ "$REPLACING" = true ]; then
  # Bash/Zsh: alias is a single line — delete just that line
  sed -i.tmp '/^alias claudesidian/d' "$CONFIG_FILE"
  # Fish: function spans multiple lines — delete from `function claudesidian`
  # to the matching `end`
  sed -i.tmp '/^function claudesidian/,/^end$/d' "$CONFIG_FILE"
  rm -f "$CONFIG_FILE.tmp"
fi
```
Why two separate sed calls: A combined range like /alias claudesidian\|function claudesidian/,/^end$/d would, for the alias case, keep eating lines until it found the next ^end$ somewhere else in the file (or EOF). That could nuke unrelated config below. Single-line delete for the alias, range delete for the function — never combine them.
Add command to config file: Append using the escaped command text
```
echo "$COMMAND_TEXT" >> "$CONFIG_FILE"
```
Show success message: With instructions to reload shell

Example Output

Bash/Zsh Example (with spaces in path to demonstrate escaping):

🔧 Installing claudesidian command...

📁 Vault path: /home/user/My Obsidian Vault
🐚 Shell detected: zsh
📝 Config file: /home/user/.zshrc

💾 Backup created: /home/user/.zshrc.backup-20250107-143025

✅ Installed! Added to /home/user/.zshrc:
   alias claudesidian='(cd "/home/user/My Obsidian Vault" && (claude --resume 2>/dev/null || claude))'

🔄 To activate, run:
   source ~/.zshrc

   Or start a new terminal session.

✨ Test it: Type 'claudesidian' from any directory!

Fish Shell Example:

🔧 Installing claudesidian command...

📁 Vault path: /home/user/My Obsidian Vault
🐚 Shell detected: fish
📝 Config file: /home/user/.config/fish/config.fish

💾 Backup created: /home/user/.config/fish/config.fish.backup-20250107-143025

✅ Installed! Added to /home/user/.config/fish/config.fish:
   function claudesidian
    cd "/home/user/My Obsidian Vault" && (claude --resume 2>/dev/null; or claude)
    cd -
end

🔄 To activate, run:
   source ~/.config/fish/config.fish

   Or start a new terminal session.

✨ Test it: Type 'claudesidian' from any directory!

Handling Special Characters

The implementation properly handles paths with:

Spaces: /Users/noah/My Vault
Quotes: /Users/noah/vault's backup
Special characters that need escaping

Paths are double-quoted and any embedded quotes/backslashes are escaped.

Fish Shell Support

Fish shell uses different syntax than Bash/Zsh:

Bash/Zsh (alias):

alias claudesidian='(cd "/path" && command)'

Fish (function):

function claudesidian
    cd "/path" && (command; or fallback)
    cd -
end

Key differences:

Fish uses function keyword instead of alias for complex commands
Fish uses ; or instead of || for fallback logic
Fish uses cd - to return to previous directory (instead of subshell)
Multi-line function definition instead of single-line alias

The installation automatically detects Fish and uses the correct syntax.

Security Considerations

This command modifies your shell configuration file (a sensitive operation). Safety measures:

You'll see exactly what will be added before any changes
Timestamped backup is automatically created before modification
Vault path is properly escaped to prevent injection attacks
Only the claudesidian command is modified - nothing else in your config
Asks permission before replacing existing commands

If anything goes wrong, restore from: $CONFIG_FILE.backup-YYYYMMDD-HHMMSS

Important Notes

The command uses a subshell () (or cd - in Fish) so it returns to your original directory after
Automatically tries to resume existing sessions, falls back to new session
If alias/function already exists, asks user if they want to replace it
Always shows what will be added before modifying config files
Always creates timestamped backup of config file before modifying (format: YYYYMMDD-HHMMSS)
Backups are kept indefinitely - users can manually clean up old backups if needed
Shows backup location so users know where to restore from if needed

Usage Examples

Install for your default shell (auto-detected):

/install-claudesidian-command

Install for specific shell (override auto-detection):

/install-claudesidian-command zsh
/install-claudesidian-command bash
/install-claudesidian-command fish

When to specify shell:

You use multiple shells and want to install for a specific one
Auto-detection picked the wrong shell
You're setting up for someone else

How It Works

Bash/Zsh (alias with subshell):

alias claudesidian='(cd "/path/to/vault" && (claude --resume 2>/dev/null || claude))'

(cd "/path/to/vault" && ...) - Subshell that changes directory temporarily (path is double-quoted for safety)
claude --resume 2>/dev/null - Tries to resume existing session, suppresses error
|| claude - If resume fails (no session), starts new session
After Claude exits, subshell closes and returns to original directory automatically

Fish (function with cd -):

function claudesidian
    cd "/path/to/vault" && (claude --resume 2>/dev/null; or claude)
    cd -
end

cd "/path/to/vault" - Changes to vault directory (path is double-quoted for safety)
claude --resume 2>/dev/null - Tries to resume existing session, suppresses error
; or claude - If resume fails (no session), starts new session (Fish syntax)
cd - - Returns to previous directory after Claude exits