Reads the next entry from the protocols table.
    Format
      #include  <netdb.h>
      struct protoent *getprotoent();

1  –  Description

    This function returns a pointer to a protoent structure
    containing the data from the protocols table. For information
    about the protoent structure, refer to protoent Structure.
    The getprotoent() function keeps an index to the table, allowing
    successive calls to be used to search the entire table.
    All information is contained in a static area, so it must be
    copied to be saved.
    Related Functions
    See also getprotobyname() and getprotobynumber().

2  –  Return Values

    NULL               Indicates the end of the table or an error.
    x                  A pointer to a protoent structure.