檔案型別測試

-e 條件運算子測試檔案是否存在（包括所有檔案型別：目錄等）。

if [[ -e $filename ]]; then
  echo "$filename exists"
fi

還有針對特定檔案型別的測試。

if [[ -f $filename ]]; then
  echo "$filename is a regular file"
elif [[ -d $filename ]]; then
  echo "$filename is a directory"
elif [[ -p $filename ]]; then
  echo "$filename is a named pipe"
elif [[ -S $filename ]]; then
  echo "$filename is a named socket"
elif [[ -b $filename ]]; then
  echo "$filename is a block device"
elif [[ -c $filename ]]; then
  echo "$filename is a character device"
fi
if [[ -L $filename ]]; then
  echo "$filename is a symbolic link (to any file type)"
fi

對於符號連結，除了 -L 之外，這些測試適用於目標，並且對於斷開的連結返回 false。

if [[ -L $filename || -e $filename ]]; then
  echo "$filename exists (but may be a broken symbolic link)"
fi

if [[ -L $filename && ! -e $filename ]]; then
  echo "$filename is a broken symbolic link"
fi