These are the source files for the USESPECIAL and DIRREADER programs disussed in the March 2010 edition of IBM i Extra
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SPECIAL File Program DIRREADER
H DftActGrp(*No) BndDir('QC2LE')
H Option(*NoDebugIO : *SrcStmt)
// DirReader
// - Used as SPECIAL file to read entries in a specified directory
// - Actual directory to open given by the fifth (extra) parm
/Copy FSDIRPROT
/Copy DIRDATA
// Prototype for CEEUTCO API - Obtains current time zone offset
D CEEUTCO PR
D Hours 10I 0
D Mins 10I 0
D Secs 8F
D fc 12A options(*omit)
// Prototype to keep the compiler happy
D DirReader Pr ExtPGM('DIRREADER')
D requestedAction...
D 1a
D statusFlag 1a
D errorCode 5s 0
D recordData LikeDS(directoryData)
D directoryToOpen...
D 640a Varying
// Procedure Interface used instead of *Entry PList
D DirReader PI
// First four are the standard parameter definitions
// passed for SPECIAL files from the RPG program
D action 1a
D status 1a
D error 5s 0
D recordData LikeDS(directoryData)
// This is the extra parameter specified within the RPG program
// In this case it supplies the name of the directory to open
D dirName 640a Varying
* Constants for SPECIAL file operation requests
D OPEN C 'O'
D READ C 'R'
D CLOSE C 'C'
D EOF C '1'
D ERR C '2'
D OK C '0'
D pdir S *
D message S 52a
// Definitions for time zone offset calculations
D hours S 10i 0
D minutes S 10i 0
D offsetSeconds S 8f
D epoch c z'1970-01-01-00.00.00'
D adjustedEpoch s z
/FREE
Select;
When action = READ;
p_dirEnt = ReadDir( pdir ); // Read next directory entry
If p_dirEnt <> *Null; // If pointer is valid we have a record
recordData.name = %Subst( dE_name: 1: dE_nameLen );
// Use the stat() function to retrieve informaqtion for the record
If Stat( recordData.name: p_statDS ) < 0; // CHeck for failure
dirName = 'File: ' + recordData.name; // Identify failing file name
ExSr ReportError;
Else;
// Create required entries in the record buffer
recordData.created = adjustedEpoch + %seconds( st_ctime );
recordData.accessed = adjustedEpoch + %seconds( st_atime );
recordData.modified = adjustedEpoch + %seconds( st_mtime );
recordData.type = st_objtype;
status = OK;
EndIf;
Else; // otherwise we're at the end of the "File"
status = EOF;
Endif;
When action = OPEN;
pdir = OpenDir( dirName );
If pdir = *Null; // If pointer is null then open failed
ExSr ReportError; // Obtains error details and reports failure
EndIf;
When action = CLOSE;
CloseDir( pdir );
EndSl;
Return;
BegSr ReportError;
// Obtains errno and sets it into the file's feedback area
status = ERR;
p_errno = GetPtr_errno();
error = errno;
// Form basic error message
If action = OPEN;
message = 'Open error: ' + %Str( strError(errno));
Else;
message = 'Read error: ' + %Str( strError(errno));
EndIf;
Dsply message;
EndSr;
// Routine calculates an epoch timestamp adjusted to account for
// the current time zone offset. This is then used to produce
// correct timestamps for dates in the directory entries.
BegSr *InzSr;
// Call CEEUTCO to obtain current time zone offset in seconds
CEEUTCO( hours: minutes: offsetSeconds: *omit );
// Then add them to the base date to form adjusted epoch
adjustedEpoch = epoch + %seconds( %int( offsetSeconds ) );
EndSr;
Program USESPECIAL - sample program that uses the DIRREADER special file
FDirEntriesIF F 732 SPECIAL PgmName('DIRREADER')
F PList(DirReaderParm)
F UsrOpn
FQPrint O F 132 PRINTER
/Copy DirData
D directoryName S 640a Varying
D Inz('/Partner400')
D message S 52a
D shortName S 34a
/Free
Open(E) DirEntries;
If %Error;
message = 'Directory: ' + directoryName; // Report error and quit
Dsply message;
*InLR = *On;
Return;
EndIf;
Dou %EOF(DirEntries);
Read(E) DirEntries directoryData;
If ( not %Error ) AND ( not %EOF(DirEntries) );
shortName = name;
except main;
ElseIf %Error;
message = directoryName; // Report (truncated) file name and quit
Dsply message;
Leave; // Exit read loop
EndIf;
EndDo;
*InLR = *On;
/End-free
// SPECIAL files need a PList for extra parms. Sadly we
// have to code that in fixed form but we hide it down here!
C PListDummy BegSr
C DirReaderParm PList
C Parm directoryName
C EndSr
OQPrint E main
O type 12
O created 40
O accessed 68
O modified 96
O shortName 132
Source IFSDIRPROT - prototypes for IFS routiines
// IFSDIRPROT - Prototypes for IFS directory processing
// - Includes DS definitions for directory entry and
// stat() data
D OpenDir Pr * ExtProc('opendir')
D
D ppath * Value Options(*String)
D ReadDir Pr * ExtProc('readdir')
D pdirectory * Value
D CloseDir Pr 10I 0 ExtProc('closedir')
D pdirectory * Value
D Stat Pr 10I 0 ExtProc('stat')
D * Value Options(*String)
D * Value
// Function and data definitions for obtaining current errno value and string
D GetPtr_errno Pr * ExtProc('__errno')
D
D p_errno S *
D p_errnoTxt S *
D errno S 10I 0 Based(p_errno)
D strerror Pr * extproc('strerror')
D errno 10I 0 value
// RPG Translation of C member STAT from file SYS in library QSYSINC
D p_statDS S * Inz(%addr(statDS))
D statDS DS
D st_mode 10U 0
D st_ino 10U 0
D st_nlink 5U 0
D st_pad 2A
D st_uid 10U 0
D st_gid 10U 0
D st_size 10I 0
D st_atime 10I 0
D st_mtime 10I 0
D st_ctime 10I 0
D st_dev 10U 0
D st_blksize 10U 0
D st_allocsize 10U 0
D st_objtype 12A
D st_codepage 5U 0
D st_reserved1 62A
D st_ino_gen_id 10U 0
// DS for directory entry information retrieved by readdir
D dirEnt DS Based(p_dirEnt)
D dE_res1 16a
D dE_genId 10u 0
D dE_fileNo 10u 0
D dE_recLen 10u 0
D dE_res3 10i 0
D dE_res4 6a
D dE_res5 2a
D dE_NLSinfo
D dE_CCSID 10i 0 Overlay(dE_NLSInfo)
D dE_country 2a Overlay(dE_NLSInfo: *Next)
D dE_language 3a Overlay(dE_NLSInfo: *Next)
D dE_res6 3a Overlay(dE_NLSInfo: *Next)
D dE_nameLen 10u 0
D dE_name 640a
// End of source IFSDIRPROT
Source DIRDATA Definition of data passed back from special program
d directoryData DS 732
d type 12a
d name 640a Varying
d created z
d accessed z
d modified z
d DIRECTORY c '*DIR'
d FILE c '*FILE'
d SYMLINK c '*SYM'
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