Translates cobol statements to machine language instructions, producing an object program 5. The linkage section has to be as long as the parameterlist of the caller. Linkage section in cobol courses with reference manuals and examples pdf. Cobol programming table of contents sysedcomputer education techniques, inc. The precompiler or the cobol compilers cics coprocessor will generate the appropriate using for the procedure division so the program has addressability to the dfhcommarea structure. It can use a cobol call statement or a cics xctl command to call a subprogram at the same level level 2. Cobol call programs using linkage free openmentor.
The following shows typical cobol instructions necessary to control subprogram linkage. Thus, when the procedure division of a subprogram executes, references to the linkage section data refer instead to the calling program data. If you are using a linkage section, first 2 bytes specify the length of the variable. In a cics cobol program invoked via an exec cics link, the linkage section must contain an 01 level structure with the name dfhcommarea. Cobdump cobdump is a useful little utility subroutine to produce a formatted hexadecimal and character. In the calling program, the code for parts partcode and the part number.
Linkage section mainly used in subprograms where to sendreceive the data between the programs from main programcalling program by using the layouts. A separate address of special register is provided for each record in the linkage section. Linkage section in cobol tutorial 11 april 2020 learn linkage. What is maximum length of linkage section in a cobol prg. Cobol advantages englishlike solves business problems handles large volumes of data universal and standardized compatible and transportable easy to maintain supports a variety of file organizations 6. Cobol tutorial cobol data division,file section,workingstorage section, linkage section, environment division, procedure division, mainframe cobol, cobol tutorial this tutorial covers most imporant topics of cobol topics like perform, call, string,unstring,comp,comp3,inspect,file,sequential file,indexed file etc once can post their cobol questions here in mainframe gurukul forums. Conceptually, a c function prototype is similar to a cobol linkage section. Which wipes out 990 bytes of presumably good data back in the calling program, causing all manner of confusing symptoms such as divide by zero, invalid function call, and danger, will robinson.
In the electronic pdf file, this symbol represents a postit note that allows you to. Linkage section in cobol tutorial 21 april 2020 learn. The subprogram receives the address of special register for the recordname you specify. In cobol, the call verb is used to invoke one program from another. A subprogram executing at level 2 can use the cobol goback or stop run statements, or the cics return command to terminate and return to the level 1 calling program. Passing data using callby reference, by value, or by content. Tops10tops20 cobol68 language manual living computer.
1066 1234 1002 1176 1189 1249 1448 806 1192 326 460 1217 1463 309 1031 37 535 686 1274 131 1276 148 82 1131 1490 971 287 996 991 673 346 1387 990 82 791