Helpful git aliases

git-aliases.sh

#!/usr/bin/env bash
# bash: `bash ./alias.sh` (requires sudo in macOS)
# zsh: `zsh ./alias.sh`
main() {
  local -ra aliases=(
    # gitgo : Alias for git add, commit with amend, update commit date and force push
    "alias gitgo='git add . && git commit --amend --no-edit --reset-author && git push -f'"
    # gitc  : Alias for counting total characters in last commi heading
    "alias gitc='git log --pretty=format:%Creset%s --no-merges -1 | wc -c'"
    # gita  : Alias for amending to latest commit
    "alias gita='git add . && git commit --amend --no-edit --allow-empty'"
  )
  
  # Process each alias for each shell config file
  while IFS= read -r file; do
    for alias in "${aliases[@]}"; do
      set_persistent_alias "$alias" "$file"
    done
  done < <(get_alias_files)
  
  if is_windows; then
    windows_init_path
  fi
}


set_persistent_alias() {
  local -r alias="$1"
  local -r file="$2"
  
  if ! create_file "$file"; then
    log_error "Failed to create the file: $file."
    return 1
  fi
  if grep -Fxq "$alias" "$file"; then
    echo "[$file] Alias already exists: $alias"
  else
    command="echo \"$alias\" >> \"$file\""
    if type "sudo" &> /dev/null; then # Git Bash on Windows does not have sudo
      command="sudo $command"
    fi
    if eval "$command"; then
      echo "[$file] Saved alias"
    else
      log_error "[$file] Failed to save alias"
    fi
  fi
  # shellcheck disable=SC1090
  source "$file"
  if is_windows; then
    windows_set_alias "$alias"
  fi
}

windows_set_alias() {
  local -r alias="$1"
  
  # Initialize Windows environment
  local batch_dir="$HOME/bin"
  create_dir "$batch_dir"
  
  local shell_cmd
  if command_exists 'bash'; then
    shell_cmd="bash"
  elif command_exists 'sh'; then
    shell_cmd="sh"
  else
    log_error "No shell found (bash or sh)"
    return 1
  fi
  local alias_name
  alias_name=$(echo "$alias" | sed -n "s/alias \([^=]*\)=.*/\1/p")
  if [[ -z "$alias_name" ]]; then
    log_error "Failed to parse alias name: $alias"
    return 1
  fi
  # Extract the alias command - everything after 'alias name='
  local alias_command
  alias_command=$(echo "$alias" | sed "s/alias $alias_name=//")
  # Remove the outer quotes if present
  if [[ "$alias_command" =~ ^\'.*\'$ ]]; then
    alias_command="${alias_command:1:-1}"
  elif [[ "$alias_command" =~ ^\".*\"$ ]]; then
    alias_command="${alias_command:1:-1}"
  fi
  if [[ -z "$alias_command" ]]; then
    log_error "Failed to parse alias command: $alias"
    return 1
  fi
  # Create a batch file for the alias
  local batch_file="$batch_dir/$alias_name.bat"
  if ! create_file "$batch_file"; then
    log_error "Failed to create the batch file: $batch_file."
    return 1
  fi
  # Escape special characters for batch files
  local escaped_command
  escaped_command=$(echo "$alias_command" | sed 's/"/\\"/g')
  # Write the batch file content
  cat > "$batch_file" << EOF
@echo off
$shell_cmd -c "$escaped_command"
EOF
  echo "[$batch_file] Created Windows batch alias"
}

windows_init_path() {
  local unix_batch_dir="$HOME/bin"
  if [[ ":$PATH:" != *":$unix_batch_dir:"* ]]; then
    echo "Adding $unix_batch_dir to PATH for current session"
    export PATH="$unix_batch_dir:$PATH"
  fi
  if ! command_exists 'reg'; then
    log_error 'Reg command is missing, cannot update PATH variable.'
    return 1
  fi
  local -r windows_batch_dir=$(convert_to_windows_path "$unix_batch_dir")
  local current_path
  current_path=$(MSYS_NO_PATHCONV=1 reg query "HKCU\Environment" /v "PATH" 2>/dev/null | grep PATH | sed 's/.*REG_SZ//')
  if [[ -n "$current_path" && "$current_path" != *"$windows_batch_dir"* ]]; then
    echo "Adding $windows_batch_dir to PATH permanently (requires admin rights)"
    MSYS_NO_PATHCONV=1 \
      reg add "HKCU\Environment" \
      /v "PATH" \
      /t "REG_EXPAND_SZ" \
      /d "$current_path;$windows_batch_dir" \
      /f
  fi
}

get_alias_files() {
  local -a files=()
  if command_exists 'zsh'; then
    files+=("$HOME/.zshrc")
  fi
  if command_exists 'bash'; then
    if [ "$(uname -s)" == "Darwin" ]; then
      files+=("$HOME/.bash_profile")
    else # tested on Windows
      files+=("$HOME/.bashrc")
    fi
  fi
  if [ ${#files[@]} -eq 0 ]; then
    log_error 'Unkown shell'
    exit 1
  fi
  printf "%s\n" "${files[@]}"
}

is_windows() {
  local -r os=$(uname -s)
  # Check for MINGW (with or without version info), CYGWIN, or Windows_NT
  [[ "$os" =~ ^MINGW(32|64)_NT ]] || [[ "$os" =~ ^CYGWIN_ ]] || [[ "$os" == "Windows_NT" ]]
}

convert_to_windows_path() {
  local unix_path="$1"
  
  # Try to use cygpath if available
  if command_exists 'cygpath'; then
    cygpath -w "$unix_path"
    return
  fi
  
  # Fallback to manual conversion
  # Convert /c/Users/bob/bin to C:\Users\bin
  echo "$unix_path" | sed -e 's|^/\([a-zA-Z]\)/|\1:\\|' -e 's|/|\\|g'
}

create_dir() {
  local dir_path="$1"
  if [ -d "$dir_path" ]; then
    return 0
  fi
  echo "Creating directory: $dir_path"
  if ! mkdir -p "$dir_path"; then
    log_error "Failed to create the directory: $dir_path"
    return 1
  fi
  return 0
}

create_file() {
  local file_path="$1"
  if [ -z "$file_path" ]; then
    log_error 'Missing file path.'
    return 1
  fi
  
  # If it's a directory, just create it
  if [[ "$file_path" == */ ]]; then
    if ! create_dir "$file_path"; then
      return 1
    fi
    return 0
  fi
  
  local parent_dir
  if ! parent_dir=$(dirname "$file_path"); then
    log_error "Could not determine the parent directory for the path: $file_path"
    return 1
  fi
  
  if ! create_dir "$parent_dir"; then
    return 1
  fi
  
  if [ ! -f "$file_path" ]; then
    echo "Creating file: $file_path"
    if ! touch "$file_path"; then
      log_error "Failed to create the file: $file_path"
      return 1
    fi
  fi
}

command_exists() {
    local -r command_name="$1"
    command -v "$command_name" &> /dev/null
}

log_error() {
  local -r message="$1"
  >&2 echo "Error: $message"
}



main