getuid(2)                                                     getuid(2)

  getuid()

  NAME

    getuid(), geteuid() - get user identification

  SYNOPSIS

    #include 
    #include 

    uid_t getuid (void)
    uid_t geteuid (void)

  DESCRIPTION

    The getuid(2) function returns the real user ID of the calling process.
    The geteuid(2) function returns the effective user ID of the calling
    process.

    The real user ID is that of the user who has invoked the program.

    The effective user ID is the user ID of the process, if it has the set-
    user-ID mode set. Since the effective user ID gives the process additional
    permissions during execution, getuid(2) is used to determine the real user
    ID of the calling process.

  ERRORS

    The getuid(2) and geteuid(2) functions are always successful, and no
    return value is reserved to indicate an error.

  SEE ALSO

    getgid(2)

  USAGE NOTES

    All of these functions are thread safe.

    All of these functions are async-signal safe.