NAME

OS390::Stdio - z/OS and OS/390 standard I/O functions with POSIX/XPG extensions

SYNOPSIS


            
              
              use OS390::Stdio qw( &dynalloc &dynfree 
                     &get_dcb &getname &pds_mem &sysdsnr
                     &mvsopen &mvswrite 
                     &flush &forward &rewind &resetpos
                     &remove &tmpnam 
                     &smf_record
                     &svc99 
                     &vsamdelrec &vsamlocate &vsamupdate
  # future dslist        &dsname_level &vol_ser 
                   );
@dslist = dsname_level("FRED");
$uniquename = tmpnam;
$fh = mvsopen("//MY.STUFF","a recfm=F") or die $!;
$name = getname($fh);
print $fh "Hello, world!\n";
flush($fh);
rewind($fh);
$line = <$fh>;
undef $fh;  # closes data set
$fh = mvsopen("dd:MYDD(MEM)", "recfm=U");
sysread($fh,$data,128);
close($fh);
remove("dd:MYDD(MEM)");
@members = pds_mem("//'SYS1.PARMLIB'");
@aliases = pds_mem("//'SYS1.PARMLIB'",1);

DESCRIPTION

This package gives Perl scripts running on z/OS or OS/390 access via POSIX extensions to several C stdio operations not available through Perl's CORE I/O functions. The specific routines are described below. These functions are prototyped as unary operators, with the exception of mvsopen which takes two arguments, mvswrite and smf_record each of which takes three arguments, svc99 which take several arguments, and tmpnam which takes none.

All of the routines are available for export, though none are exported by default. All of the constants used by vsamupdate to specify update options are exported by default, other constants that are not exported are available via explicit calls to constant or via Exporter tags *_CONSTANTS (see below).

The routines are associated with the Exporter tag FUNCTIONS, the experimental routines are associated with the Exporter tag EXPERIMENAL, and the stdio.h VSAM constants are associated with the Exporter tag CONSTANTS, so you can more easily choose what you'd like to import:


            
              
              # import constants, but not functions
use OS390::Stdio;  # same as use OS390::Stdio qw( :DEFAULT );
# import functions, but not constants
use OS390::Stdio qw( !:CONSTANTS :FUNCTIONS ); 
# import both
use OS390::Stdio qw( :CONSTANTS :FUNCTIONS ); 
# import nothing
use OS390::Stdio ();
# import everything
use OS390::Stdio qw(
    :CONSTANTS :FUNCTIONS :EXPERIMENTAL
    :ALCUNIT_CONSTANTS :DISP_CONSTANTS :DSORG_CONSTANTS :RECFM_CONSTANTS
    :MISCFL_CONSTANTS :VSAM_CONSTANTS :DSNT_CONSTANTS :PATH_CONSTANTS
                   );

Of course, you can also choose to import specific functions by name, as usual.

This package ISA IO::File, so that you can call IO::File methods on the handles returned by mvsopen. The IO::File package is not initialized, however, until you actually call a method that OS390::Stdio doesn't provide. This is done to save startup time for users who don't wish to use the IO::File methods.

CONSTANTS

The constants handled by OS390::Stdio derive from #define preprocessor statements in three C header files on z/OS or OS/390: stdio.h, fcntl.h, and dynit.h.

stdio.h constants

Constants related to VSAM usage in stdio.h have corresponding constants in OS390::Stdio. They are:


            
              
              &KEY_FIRST &KEY_LAST &KEY_EQ &KEY_EQ_BWD &KEY_GE
&RBA_EQ &RBA_EQ_BWD

These are ordinarily imported by either use OS390::Stdio; or use OS390::Stdio qw(:CONSTANTS);

fcntl.h constants

fcntl.h constants intended for use with open() are also handled by OS390::Stdio. They are:


            
              
              &O_APPEND &O_CREAT &O_EXCL &O_NDELAY &O_NOWAIT
&O_RDONLY &O_RDWR &O_TRUNC &O_WRONLY

These are ordinarily not imported.

dynit.h constants

Constants defined in dynit.h are grouped and mapped to slightly different names by OS390::Stdio. There are 8 distinct groupings of dynit.h constants: ALCUNIT_CONSTANTS, DISP_CONSTANTS, DSORG_CONSTANTS, RECFM_CONSTANTS, MISCFL_CONSTANTS, VSAM_CONSTANTS, DSNT_CONSTANTS, and PATH_CONSTANTS. These constants are frequently used with routines like dynalloc() and dynfree().

ALCUNIT_CONSTANTS

Corresponding to allocation unit constants. These can either be imported via use OS390::Stdio qw(:ALCUNIT_CONSTANTS); or they can be used individually as in:


            
              
              use OS390::Stdio;
my $cylinder = OS390::Stdio::constants('ALCUNIT_CYL');