Variable Length Input File
in [Cobol]
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From: Pete Dashwood on 27 Dec 2006 20:43 "Howard Brazee" <howard(a)brazee.net> wrote in message news:2455p25b0d7efq4tg4k8bdrd1o6d3qa3ih(a)4ax.com... > Shops I was with used to use variable length files quite a bit until > around a couple of decades ago - when they switched to files with > header and detail records for variable data - which dominated for a > decade or so until they switched to external databases for the same > kind of data. Yes, that is certainly my approach; let the DBMS sort it out... Pete
From: Anonymous on 28 Dec 2006 05:14 In article <4vglitF1cepuaU1(a)mid.individual.net>, Pete Dashwood <dashwood(a)removethis.enternet.co.nz> wrote: > ><docdwarf(a)panix.com> wrote in message news:emtr65$6b5$1(a)reader2.panix.com... [snip] >> Therein lies the difficulty, Mr Dashwood... as I understand the original >> poster's request the LRECL of TESTA changes from one run to the next; >> there is no *the* LRECL size. Once again, from >> ><http://groups.google.com/group/comp.lang.cobol/msg/e2bd0f47c45850c8?dmode=source> >> >> --begin quoted text: >> >> TESTA doesn't always have the same LRECL. Sometime TESTA will be defined >> in the JCL with LRECL=30. Other times, it will be have LRECL=70. And so >> on. My problem is how should TESTA be represented in FD? >> >> --end quoted text > >Ah, yes...I had overlooked that. Thanks for clarifying. It looks to me like >RECFM=VB has to be a requisite (maybe RECFM=U, though I've not had any >experience with that...). If it CAN be done with RECFM=FB, it'll be very >interesting to see how... > >Thanks for your time. You're most welcome, Mr Dashwood... would that the originator of this thread might be equally as gracious but... perhaps the due-date for this particular homework assignment has passed. DD
From: Roger While on 29 Dec 2006 00:50 Doesn't help for mainframe presumably but MicroFocus (also OpenCOBOL) have CBL_OPEN_FILE, CBL_READ_FILE, CBL_WRITE_FILE, CBL_CLOSE_FILE calls to manipulate files at the "raw" level without any SELECT/FD's. The length is passed as a parameter to read any specific chunk.
From: Robert Jones on 29 Dec 2006 06:25 manubay(a)pacbell.net wrote: > Is there a way in Cobol to handle an input file that has variable > LRECL? If there is, how would it be defined in the FD section? Thank > you. I wrote a program in 1979 with the folowing input FDs, on an IBM mainframe, presumably with OS/VS2 COBOL. * fixed length record FD FD FILE1 RECORDING MODE IS F LABEL RECORDS ARE STANDARD BLOCK CONTAINS 0 RECORDS RECORD CONTAINS 0 CHARACTERS. 01 IFAREC. 03 IFABYTE PIC X OCCURS 10000. SKIP3 * variable length record FD FD VILE1 RECORDING MODE IS V LABEL RECORDS ARE STANDARD BLOCK CONTAINS 0 RECORDS RECORD CONTAINS 0 CHARACTERS. 01 IVAREC. 03 IVABYTE PIC X OCCURS 10000. SKIP3 It was still working in the late 1980s. It is quite likely that it would still work, though the current standard and maybe the 1985 one too, has made the RECORDING MODE clause obsolete (as well as the LABEL clause), thereby apparently making it impossible for the compiler to usefully detect whether the mode is fixed or variable in these cases. However, IBM still permits their use as an extension, but for how long and whether with the same effect, I don't know. A format 3 RECORD clause (aa per 2002 standard) might do the trick depending on the compiler (as the standard says that it is implementor defined how it is actually implemented with respect to some of hte details) i.e. RECORD CONTAINS integer-4 TO integer-5 CHARACTERS, where integer-4 must be greater than or equal to zero (anyone like to tell me how to detect/write a zero length record, when it doesn't have a 4byte RDW and what its use might be!) and integer-5 must be greater than integer-4. This construct might make it possible for the same FD statement to read either fixed or variable record length files for some implementors. Robert
From: Vivian on 29 Dec 2006 11:01
manubay(a)pacbell.net wrote: > Is there a way in Cobol to handle an input file that has variable > LRECL? If there is, how would it be defined in the FD section? Thank > you. .......... The problem is all inside your head She said to me The answer is easy if you Take it logically I'd like to help you in your struggle ......... Sorry, the song got stuck in my head while reading through this one...... The answer is to find yourself a real veteran, do it in assembler on the mainframe, and call the assembler routine from your cobol program. |