rdmake (1) --- make a relation from data file            02/22/82


            _U_s_a_g_e

                 rdmake


            _D_e_s_c_r_i_p_t_i_o_n

                 'Rdmake'  is part of the toy relational data base management
                 system 'rdb'.  It creates an 'rdb' relation from a data file
                 and a description file.  The  relation  data  is  read  from
                 standard input 1 and the description file is read from stan-
                 dard  input  2  (see below).  The new relation is written to
                 standard output.  The output  relation  is  displayed  in  a
                 readable format if standard output is directed to a terminal
                 (display  in  binary  would be quite a mess); otherwise, the
                 output relation is written in binary,  internal  format  for
                 processing by other 'rdb' programs.

                 Identical   tuples   are  not  removed  from  the  resulting
                 relations.   These  can  be  removed  using   'rdsort'   and
                 'rduniq'.

                 The  description  file  is  very similar in structure to the
                 output format file used  by  'rdextr'.   Each  line  of  the
                 description  file causes the creation of a new domain in the
                 relation and describes how the data for that domain is to be
                 obtained.  Each line has one of the following formats:

                       i       <domain name> [ d[<delim>] ] [ l<flen> ]
                       r       <domain name> [ d[<delim>] ] [ l<flen> ]
                       s<slen> <domain name> [ d[<delim>] ] [ l<flen> ]

                 The first two entries in each line describe  the  format  of
                 the  relation.  The first format describes an integer domain
                 (containing 32 bit integers), the second  describes  a  real
                 domain  (containing  64 bit reals), and the last describes a
                 string domain containing <slen>  character  strings  (<slen>
                 must  be  a positive integer).  The <domain name> must begin
                 with a letter and contain only letters, digits,  and  under-
                 scores.  Case is significant in identifiers.

                 The  last two (optional) entries in each format describe how
                 each domain is to be obtained from the data file.  Data  for
                 each  tuple  is  taken  from a single line in the data file.
                 Fields are extracted in the order of lines in  the  descrip-
                 tion  file.   Each field is extracted by first skipping over
                 any leading delimiter characters specified by <delim> in the
                 "d<delim>" entry  (if  the  entry  is  omitted,  <delim>  is
                 assumed  to  be  a  blank;  if  "d"  is  specified without a
                 delimiter, no delimiter is allowed).   Then  characters  are
                 collected  up  to  the  next  occurrence of <delim>.  In any
                 case, no more  than  <flen>  characters  are  collected  (if
                 "l<flen>"  is  omitted, <flen> is assumed to be a very large
                 number).  The extracted  field  is  then  converted  to  the
                 proper  internal  format  and placed in the tuple.  Integers
                 and reals are converted  into  binary  representations  with


            rdmake (1)                    - 1 -                    rdmake (1)




            rdmake (1) --- make a relation from data file            02/22/82


                 'gctol' and 'ctod'; strings are blank padded to full length.
                 For example,

                       s6 pno
                       s15 pname l15 d
                       i qty d,
                       r price d, l10

                 "pno" is a string containing 6 characters; it is obtained by
                 skipping  blanks  and  then  collecting characters up to the
                 next blank.  "Pname" is a string containing  15  characters;
                 it  is  obtained  by  taking  exactly 15 characters from the
                 input line (if a NEWLINE is  encountered,  spaces  are  sup-
                 plied).   "Qty"  is  an  integer domain that is extracted by
                 skipping leading commas, collecting  characters  up  to  the
                 next comma, and then converting the resulting string into an
                 integer  with  'gctol'.   "Price"  is  a  real domain; it is
                 extracted by skipping leading commas, collecting  characters
                 up  to  the next comma (but not more than 10), and then con-
                 verting the resulting string into a real using 'ctod'.


            _E_x_a_m_p_l_e_s

                 p.data> p.des> rdmake | rdsort | rdjoin >p.rel
                 sp.des>2 rdmake >sp.rel


            _M_e_s_s_a_g_e_s

                 "Illegal length"
                 "Illegal data type"
                 "Illegal domain name"
                 "Duplicate name"
                 "Can't add domain"
                 "Illegal input length"
                 "Unrecognized word"
                 "<integer>:  bad integer"
                 "<real>:  bad real"


            _B_u_g_s

                 If standard output is directed to "/dev/lps",  the  relation
                 is written in binary.
                 
                 An  empty  field cannot be specified by two occurrences of a
                 delimiter.


            _S_e_e _A_l_s_o

                 ctod (2), gctol (2), rdcat  (1),  rdextr  (1),  rdjoin  (1),
                 rdmake  (1), rdprint (1), rdproj (1), rdsel (1), rdsort (1),
                 rduniq (1)



            rdmake (1)                    - 2 -                    rdmake (1)