os.FileExists
os.FileExists PATH
Reports whether the file or directory exists.
os.Getenv
os.Getenv VARIABLE
Returns the value of an environment variable, or an empty string if the environment variable is not set.
os.ReadDir
os.ReadDir PATH
Returns an array of FileInfo structures sorted by file name, one element for each directory entry.
os.ReadFile
os.ReadFile PATH
Returns the contents of a file.
os.Stat
os.Stat PATH
Returns a FileInfo structure describing a file or directory.