Compiler Directives and Dialects

File Handling

Chapter 6: Run-time Triggers, Configuration and Switches

This chapter describes:

How the order of arguments supplied to trigger programs is affected by the X/Open COBOL standard, and how you can use the arguments_are_initial run-time tunable to change the argument order
Changes that have been made to run-time configurables, such as run-time tunables, switches and environment variables, that might affect applications you want to migrate

6.1 Triggers

The COBOL statements ACCEPT ... FROM ARGUMENT-NUMBER and ACCEPT ... FROM ARGUMENT-VALUE are defined in the X/Open COBOL standard. The standard states that the values returned should exclude the executable name itself (except when DISPLAY 0 UPON ARGUMENT-VALUE is used). This is documented in the Language Reference.

If the COBOL program you use to start your application is a system executable, the executable name is argument 0, and any arguments on the command line are returned as expected; for example, ./progname arg1 arg2 returns two arguments, arg1 and arg2.

In Object COBOL Developer Suite V4.1 and earlier, if you used cobrun, argument 0 was the cobrun trigger. The program name was thus the first of the arguments; for example cobrun progname arg1 arg2 returned three arguments, progname, arg1 and arg2. While this conformed with the X/Open standard, it was inconsistent.

In Server Express, if you use the cobrun (or cobrun_t) trigger program, the trigger is ignored, and the program name becomes argument 0. Therefore, only the parameters are returned as arguments. For example, cobrun progname arg1 arg2 returns two arguments, arg1 and arg2

However, this does mean that the behavior is inconsistent with Object COBOL Developer Suite V4.1 and earlier (except if you are using system executables). You might, therefore, have to change the setting of the arguments_are_initial run-time tunable to enable your application to run correctly.

If arguments_are_initial is set to TRUE, then the arguments are accepted as for Object COBOL Developer Suite V4.1 and earlier. If arguments_are_initial is set to FALSE, the trigger name is ignored. By default arguments_are_initial is FALSE; this provides consistency between all executable file types, and with Net Express.

For information on setting run-time tunables, and for information on the format of the arguments_are_initial run-time tunable, see the chapter Run-time Configuration in your User's Guide.

6.2 Switches

This section describes those run-time switches that have been removed from Server Express, but were available in previous versions of COBOL for UNIX, and those switches that are new to Server Express.

For a full list of the switches available in Server Express, see the chapter Descriptions of Run-time Switches in your User's Guide.

The following switches have been removed or superseded:

A1

The A1 switch, which invoked the base Animator, has been removed from Server Express. Object COBOL Developer Suite V4.1 and earlier provided two animators: base Animator and advanced Animator. Server Express has the advanced Animator only so this switch is not needed. (There is a new A1 switch, which controls the display of trailing spaces.) The advanced Animator is described in your Debugging Guide.

e

The e switch has been removed because technical improvements in Server Express mean that the run-time system can function effectively without it.

K

The K switch, which controlled the order in which records are written to an indexed file with sequential access, has been removed from Server Express. If you want to write records in any order other than ascending order of prime key, you should use dynamic access.

p

The p switch has been removed because technical improvements in Server Express mean that the run-time system can function effectively without it.

S

The S switch, which caused duplicates in all SORT operations to be ordered, has been removed from Server Express because the SORT always orders duplicates.

s

The s switch, which specified the amount of memory allocated to internal workspace for SORT operations, has been superseded by the SORTSPACE environment variable, which is described in the appendix Environment Variables in your User's Guide.

The following switch is new:

A1

This switch controls the display of trailing spaces. It provides compatibility with earlier Micro Focus COBOL systems.

6.3 Run-time Tunables

For a full list of the run-time tunables available in Server Express, see the chapter Run-time Configuration in your User's Guide. The following run-time tunables have changed, or are superseded by new tunables or different methods of configuration.

animator_interrupt_char

The animator_interrupt_char tunable has been removed from Server Express. The animator interrupt character in Server Express is the same as the operating system interrupt character, which is by default either CTRL+C or DEL; you can change it using the operating system command:

stty intr key

where key is the character that you want to use as the interrupt character

command_line_accept

The behavior of the run-time tunable command_line_accept now affects the first READ from STDIN as well as the first ACCEPT.

core_on_error

In Server Express you cannot set the core_on_error tunable to the value 2, to mean "produce a core dump when any error condition occurs". Instead you should use just-in-time debugging or FaultFinder. Both just-in-time debugging and FaultFinder are available both in Server Express, for use during development, and Application Server, for production environments. We recommend that you use FaultFinder in production environments. The advantage of these techniques is that when an error condition occurs, the system tidies up after your program, for example, freeing up system resources and clearing file buffers. In contrast, when you use core_on_error and an error condition occurs, the system simply produces the core dump file without tidying up.

For further information on just-in-time debugging and FaultFinder see your Debugging Guide.

isam_block_size

The isam_block_size tunable has been removed from Server Express. Instead, you should use the NODESIZE configuration option in the file handler configuration file. See the chapter File Handler Configuration in your File Handling book for details.

isam_open_key_check

The isam_open_key_check tunable has been removed from Server Express. Instead, you should use the KEYCHECK configuration option in the file handler configuration file. See the chapter File Handler Configuration in your File Handling book for details.

noretry_on_decl

The noretry_on_decl tunable has been removed from Server Express. There is no equivalent to this tunable in the file handler configuration options, although the RETRYLOCK option can be switched on and off for particular files. See the chapter File Handler Configuration in your File Handling book for details.

posix_lock_prob

The posix_lock_prob tunable has been superseded by the intra_process_record_locking tunable.

routine_table_size

The routine_table_size tunable has been removed from Server Express. In Server Express there is no limit other than any limit imposed by the operating system to the number of COBOL programs that can be loaded at the same time.

same_proc_excl_detection

The same_proc_excl_detection tunable has been superseded by the intra_process_record_locking tunable.

skip_on_lock

The skip_on_lock tunable has been removed from Server Express. Instead, you should use the SKIPLOCK configuration option in the file handler configuration file. See the chapter File Handler Configuration in your File Handling book for details.

6.4 COBCTRLCHAR Environment Variable

The COBCTRLCHAR environment variable enabled you to output Escape sequences to the screen for cursor and color handling. It has been removed from this product and is obsolete. More effective methods are provided by the enhanced ACCEPT/DISPLAY syntax (for example, DISPLAY text-item AT yyxx), or run-time CBL_ calls. These methods:

Are terminal independent
Can be debugged using Animator
Are easier to maintain

For more information, refer to the Language Reference and the Adis chapter of your Character User Interfaces book.

Examples:

If an existing program outputs escape sequences and/or writes directly to tty to provide screen I/O, this code should be replaced by COBOL syntax. For example, if your program:

Displays text, use:
DISPLAY ... [AT ...]

or the library routine:

CBL_WRITE_SCR_CHATTRS
Displays graphics or line-draw characters, use the library routines:
CBL_GET_SCR_LINE_DRAW
CBL_GET_SCR_GRAPHICS

both of which return arrays of line and graphics characters correct for the current environment.
Reads the screen, use the library routine:
CBL_READ_SCR_CHATTRS
Clears the screen, use:
DISPLAY SPACES UPON CRT

or the library routine:

CBL_CLEAR_SCREEN
Sounds the terminal alarm, use:
DISPLAY ... WITH BELL
Determines the screen size, use the library routine:
CBL_GET_SCR_SIZE

Compiler Directives and Dialects

File Handling