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Sure, I read "stream files" from the IFS in RPG all the time. Its
not difficult to do, once you've got all of the calls prototyped.
At the bottom of this message, I will include my /COPY member that
contains the prototypes, and a simple example program....
(including this code makes this a fairly long message, sorry...)
Scott Klement
Information Systems Manager
Klement's Sausage Co, Inc.
"Rajeev Asthana" <Rajeev_Asthana@paramount.com> wrote:
> Hi All,
>
> Is there any way to read a file as a stream of bytes in RPG like we
> in C?
>
> Thanks very much.
>
> Rajeev.
>
Here is the member containing the prototypes (/COPY into RPG source)
In my enviornment, I keep this is LIBSOR/QRPGLESRC,IFSIO_H
----------------------------------------------------------------------
* This header file contains the constants, structures and prototypes
* for using the Integrated File System API
*
* These APIs were designed originally for use in C programming.
* Therefore bear in mind:
* 1) All strings must be null-terminated, and variable-length.
* 2) Errors are returned in the errno variable, and strings for
* them are available by calling strerror()
* 3) To use strerror(), errno, you must bind to the ILE C binding
* directory QC2LE
*
* SCK 03/24/1999
*
* To use these in your source code, you need a D-spec like this:
* D/COPY LIBSOR/QRPGLESRC,IFSIO_H
* For detailed info seee the UNIX-type APIs manual
* This header file includes (in order)
* 1) Constants
* 2) Structures
* 3) Prototypes
D* ascii code-page
D CP_ASCII C 819
D*********************************************************************
D* Flags for use in open()
D*
D* More than one can be used -- add them together.
D*********************************************************************
D* Reading Only
D O_RDONLY C 1
D* Writing Only
D O_WRONLY C 2
D* Reading & Writing
D O_RDWR C 4
D* Create File if not exist
D O_CREAT C 8
D* Exclusively create
D O_EXCL C 16
D* Truncate File to 0 bytes
D O_TRUNC C 64
D* Append to File
D O_APPEND C 256
D* Convert text by code-pag
D O_CODEPAGE C 8388608
D* Open in text-mode
D O_TEXTDATA C 16777216
D*********************************************************************
D* Access mode flags for access()
D*********************************************************************
D F_OK C 0
D R_OK C 4
D W_OK C 2
D X_OK C 1
D*********************************************************************
D* Mode Flags.
D* basically, the mode parm of open(), creat(), chmod(),etc
D* uses 9 least significant bits to determine the
D* file's mode. (peoples access rights to the file)
D*
D* user: owner group other
D* access: R W X R W X R W X
D* bit: 8 7 6 5 4 3 2 1 0
D*
D* (This is accomplished by adding the flags below to get the mode)
D*********************************************************************
D* owner authority
D S_IRUSR C 256
D S_IWUSR C 128
D S_IXUSR C 64
D S_IRWXU C 448
D* group authority
D S_IRGRP C 32
D S_IWGRP C 16
D S_IXGRP C 8
D S_IRWXG C 56
D* other people
D S_IROTH C 4
D S_IWOTH C 2
D S_IXOTH C 1
D S_IRWXO C 7
D*********************************************************************
D* File Information Structure (stat)
D*
D* struct stat {
D* mode_t st_mode; /* File mode *
D* ino_t st_ino; /* File serial number *
D* nlink_t st_nlink; /* Number of links *
D* uid_t st_uid; /* User ID of the owner of file *
D* gid_t st_gid; /* Group ID of the group of file *
D* off_t st_size; /* For regular files, the file
D* * size in bytes *
D* time_t st_atime; /* Time of last access *
D* time_t st_mtime; /* Time of last data modification *
D* time_t st_ctime; /* Time of last file status change *
D* dev_t st_dev; /* ID of device containing file *
D* size_t st_blksize; /* Size of a block of the file *
D* unsigned long st_allocsize; /* Allocation size of the file *
D* qp0l_objtype_t st_objtype; /* AS/400 object type *
D* unsigned short st_codepage; /* Object data codepage *
D* char st_reserved1[66]; /* Reserved *
D* };
D*
D p_statds S *
D statds DS BASED(p_statds)
D st_mode 10U 0
D st_ino 10U 0
D st_nlink 5U 0
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_alcsize 10U 0
D st_objtype 11A
D st_codepag 5U 0
D st_resv11 66A
D*********************************************************************
D* Group Information Structure (group)
D*
D* struct group {
D* char *gr_name; /* Group name.
D* gid_t gr_gid; /* Group id.
D* char **gr_mem; /* A null-terminated list of pointe
D* to the individual member names.
D* };
D*
D p_group S *
D group DS Based(p_group)
D gr_name *
D gr_gid 10U 0
D gr_mem * DIM(256)
D*********************************************************************
D*
D* User Information Structure (passwd)
D*
D* (Don't let the name fool you, this structure does not contain
D* any password information. Its named after the UNIX file that
D* contains all of the user info. That file is "passwd")
D*
D* struct passwd {
D* char *pw_name; /* User name.
D* uid_t pw_uid; /* User ID number.
D* gid_t pw_gid; /* Group ID number.
D* char *pw_dir; /* Initial working directory.
D* char *pw_shell; /* Initial user program.
D* };
D*
D p_passwd S *
D passwd DS BASED(p_passwd)
D pw_name *
D pw_uid 10U 0
D pw_gid 10U 0
D pw_dir *
D pw_shell *
D*********************************************************************
D* File Time Structure (utimbuf)
D*
D* struct utimbuf {
D* time_t actime; /* access time */
D* time_t modtime; /* modification time */
D* };
D*
D p_utimbuf S *
D utimbuf DS based(p_utimbuf)
D actime 10I 0
D modtime 10I 0
D*********************************************************************
D*
D* Directory Entry Structure (dirent)
D*
D* struct dirent {
D* char d_reserved1[16]; /* Reserved
D* unsigned int d_reserved2; /* Reserved
D* ino_t d_fileno; /* The file number of the file
D* unsigned int d_reclen; /* Length of this directory entr
D* * in bytes
D* int d_reserved3; /* Reserved
D* char d_reserved4[8]; /* Reserved
D* qlg_nls_t d_nlsinfo; /* National Language Information
D* * about d_name
D* unsigned int d_namelen; /* Length of the name, in bytes
D* * excluding NULL terminator
D* char d_name[_QP0L_DIR_NAME]; /* Name...null terminated
D*
D* };
D*
D p_dirent s *
D dirent ds based(p_dirent)
D d_reserv1 16A
D d_reserv2 10U 0
D d_fileno 10U 0
D d_reclen 10U 0
D d_reserv3 10I 0
D d_reserv4 8A
D d_nlsinfo 12A
D nls_ccsid 10I 0 OVERLAY(d_nlsinfo:1)
D nls_cntry 2A OVERLAY(d_nlsinfo:5)
D nls_lang 3A OVERLAY(d_nlsinfo:7)
D nls_reserv 3A OVERLAY(d_nlsinfo:10)
D d_namelen 10U 0
D d_name 640A
D*--------------------------------------------------------------------
D* Determine file accessibility
D*
D* int access(const char *path, int amode)
D*
D*--------------------------------------------------------------------
D access PR 10I 0 ExtProc('access')
D Path * Value
D amode 10I 0 Value
D*--------------------------------------------------------------------
D* Change Directory
D*
D* int chdir(const char *path)
D*--------------------------------------------------------------------
D chdir PR 10I 0 ExtProc('chdir')
D path * Value
D*--------------------------------------------------------------------
D* Change file authorizations
D*
D* int chmod(const char *path, mode_t mode)
D*--------------------------------------------------------------------
D chmod PR 10I 0 ExtProc('chmod')
D path * Value
D mode 10U 0 Value
D*--------------------------------------------------------------------
D* Change Owner/Group of File
D*
D* int chown(const char *path, uid_t owner, gid_t group)
D*--------------------------------------------------------------------
D chown PR 10I 0 ExtProc('chown')
D path * Value
D owner 10U 0 Value
D group 10U 0 Value
D*--------------------------------------------------------------------
D* Close a file
D*
D* int close(int fildes)
D*--------------------------------------------------------------------
D close PR 10I 0 ExtProc('close')
D handle 10I 0 value
D*--------------------------------------------------------------------
D* Close a directory
D*
D* int closedir(DIR *dirp)
D*--------------------------------------------------------------------
D closedir PR 10I 0 EXTPROC('closedir')
D dirhandle * VALUE
D*--------------------------------------------------------------------
D* Create or Rewrite File
D*
D* int creat(const char *path, mode_t mode)
D*--------------------------------------------------------------------
D creat PR 10I 0 ExtProc('creat')
D path * Value
D mode 10U 0 Value
D*--------------------------------------------------------------------
D* Duplicate open file descriptor
D*
D* int dup(int fildes)
D*--------------------------------------------------------------------
D dup PR 10I 0 ExtProc('dup')
D fildes 10I 0 Value
D*--------------------------------------------------------------------
D* Duplicate open file descriptor to another descriptor
D*
D* int dup2(int fildes, int fildes2)
D*--------------------------------------------------------------------
D dup2 PR 10I 0 ExtProc('dup2')
D fildes 10I 0 Value
D fildes2 10I 0 Value
D*--------------------------------------------------------------------
D* Change file authorizations by descriptor
D*
D* int fchmod(int fildes, mode_t mode)
D*--------------------------------------------------------------------
D fchmod PR 10I 0 ExtProc('fchmod')
D fildes 10I 0 Value
D mode 10U 0 Value
D*--------------------------------------------------------------------
D* Change Owner and Group of File by Descriptor
D*
D* int fchown(int fildes, uid_t owner, gid_t group)
D*--------------------------------------------------------------------
D fchown PR 10I 0 ExtProc('fchown')
D fildes 10I 0 Value
D owner 10U 0 Value
D group 10U 0 Value
D*--------------------------------------------------------------------
D* Perform File Control
D*
D* int fcntl(int fildes, int cmd, . . .)
D*--------------------------------------------------------------------
D fcntl PR 10I 0 ExtProc('fcntl')
D fildes 10I 0 Value
D cmd 10I 0 Value
D arg 10I 0 Value options(*nopass)
D*--------------------------------------------------------------------
D* Get configurable path name variables by descriptor
D*
D* long fpathconf(int fildes, int name)
D*--------------------------------------------------------------------
D fpathconf PR 10I 0 ExtProc('fpathconf')
D fildes 10I 0 Value
D name 10I 0 Value
D*--------------------------------------------------------------------
D* Get File Information by Descriptor
D*
D* int fstat(int fildes, struct stat *buf)
D*--------------------------------------------------------------------
D fstat PR 10I 0 ExtProc('fstat')
D fildes 10I 0 Value
D buf * Value
D*--------------------------------------------------------------------
D* Synchronize Changes to fIle
D*
D* int fsync(int fildes)
D*--------------------------------------------------------------------
D fsync PR 10I 0 ExtProc('fsync')
D fildes 10I 0 Value
D*--------------------------------------------------------------------
D* Truncate file
D*
D* int ftruncate(int fildes, off_t length)
D*--------------------------------------------------------------------
D ftruncate PR 10I 0 ExtProc('ftruncate')
D fildes 10I 0 Value
D length 10I 0 Value
D*--------------------------------------------------------------------
D* Get current working directory
D*
D* char *getcwd(char *buf, size_t size)
D*--------------------------------------------------------------------
D getcwd PR * ExtProc('getcwd')
D buf * Value
D size 10U 0 Value
D*--------------------------------------------------------------------
D* Get effective group ID
D*
D* gid_t getegid(void)
D*--------------------------------------------------------------------
D getegid PR 10U 0 ExtProc('getegid')
D*--------------------------------------------------------------------
D* Get effective user ID
D*
D* uid_t geteuid(void)
D*--------------------------------------------------------------------
D geteuid PR 10U 0 ExtProc('geteuid')
D*--------------------------------------------------------------------
D* Get Real Group ID
D*
D* gid_t getgid(void)
D*--------------------------------------------------------------------
D getgid PR 10U 0 ExtProc('getgid')
D*--------------------------------------------------------------------
D* Get group information from group ID
D*
D* struct group *getgrgid(gid_t gid)
D*--------------------------------------------------------------------
D getgrid PR * ExtProc('getgrgid')
D gid 10U 0 VALUE
D*--------------------------------------------------------------------
D* Get group info using group name
D*
D* struct group *getgrnam(const char *name)
D*--------------------------------------------------------------------
D getgrnam PR * ExtProc('getgrnam')
D name * VALUE
D*--------------------------------------------------------------------
D* Get group IDs
D*
D* int getgroups(int gidsetsize, gid_t grouplist[])
D*--------------------------------------------------------------------
D getgroups PR * ExtProc('getgroups')
D gidsetsize 10I 0 VALUE
D grouplist *
D*--------------------------------------------------------------------
D* Get user information by user-name
D*
D* (Don't let the name mislead you, this does not return the password,
D* the user info database on unix systems is called "passwd",
D* therefore, getting the user info is called "getpw")
D*
D* struct passwd *getpwnam(const char *name)
D*--------------------------------------------------------------------
D getpwnam PR * ExtProc('getpwnam')
D name * Value
D*--------------------------------------------------------------------
D* Get user information by user-id
D*
D* (Don't let the name mislead you, this does not return the password,
D* the user info database on unix systems is called "passwd",
D* therefore, getting the user info is called "getpw")
D*
D* struct passwd *getpwuid(uid_t uid)
D*--------------------------------------------------------------------
D getpwuid PR * extproc('getpwuid')
D uid 10U 0 Value
D*--------------------------------------------------------------------
D* Get Real User-ID
D*
D* uid_t getuid(void)
D*--------------------------------------------------------------------
D getuid PR 10U 0 ExtProc('getuid')
D*--------------------------------------------------------------------
D* Perform I/O Control Request
D*
D* int ioctl(int fildes, unsigned long req, ...)
D*--------------------------------------------------------------------
D ioctl PR 10I 0 ExtProc('ioctl')
D fildes 10I 0 Value
D req 10U 0 Value
D arg * Value
D*--------------------------------------------------------------------
D* Create Link to File
D*
D* int link(const char *existing, const char *new)
D*--------------------------------------------------------------------
D link PR 10I 0 ExtProc('link')
D existing * Value
D new * Value
D*--------------------------------------------------------------------
D* Set File Read/Write Offset
D*
D* off_t lseek(int fildes, off_t offset, int whence)
D*--------------------------------------------------------------------
D lseek PR 10I 0 ExtProc('lseek')
D offset 10I 0
D whence 10I 0
D*--------------------------------------------------------------------
D* Get File or Link Information
D*
D* int lstat(const char *path, struct stat *buf)
D*--------------------------------------------------------------------
D lstat PR 10I 0 ExtProc('lstat')
D path * Value
D buf * Value
D*--------------------------------------------------------------------
D* Make Directory
D*
D* int mkdir(const char *path, mode_t mode)
D*--------------------------------------------------------------------
D mkdir PR 10I 0 ExtProc('mkdir')
D path * Value
D mode 10U 0 Value
D*--------------------------------------------------------------------
D* Open a File
D*
D* int open(const char *path, int oflag, . . .);
D*--------------------------------------------------------------------
D open PR 10I 0 ExtProc('open')
D filename * value
D openflags 10I 0 value
D mode 10U 0 value options(*nopass)
D codepage 10U 0 value options(*nopass)
D*--------------------------------------------------------------------
D* Open a Directory
D*
D* DIR *opendir(const char *dirname)
D*--------------------------------------------------------------------
D opendir PR * EXTPROC('opendir')
D dirname * VALUE
D*--------------------------------------------------------------------
D* Get configurable path name variables
D*
D* long pathconf(const char *path, int name)
D*--------------------------------------------------------------------
D pathconf PR 10I 0 ExtProc('pathconf')
D path * Value
D name 10I 0 Value
D*--------------------------------------------------------------------
D* Get path name of object from its file id
D*
D* char *Qp0lGetPathFromFileID(char *buf, size_t size,Qp0lFID_t fileid
D*--------------------------------------------------------------------
D GetPathFID PR * ExtProc('Qp0lGetPathFromFileID')
D buf * Value
D size 10U 0 Value
D fileid 16A
D*--------------------------------------------------------------------
D* Rename File or Directory, return error if a file/dir under the
D* "new" name already exists.
D*
D* int Qp0lRenameKeep(const char *old, const char *new)
D*--------------------------------------------------------------------
D Rename PR 10I 0 ExtProc('Qp0lRenameKeep')
D old * Value
D new * Value
D*--------------------------------------------------------------------
D* Rename File or Directory. If another file/dir exists under the
D* "new" name, delete it first.
D*
D* int Qp0lRenameUnlink(const char *old, const char *new)
D*--------------------------------------------------------------------
D Replace PR 10I 0 ExtProc('Qp0lRenameUnlink')
D old * Value
D new * Value
D*--------------------------------------------------------------------
D* Read From a File
D*
D* ssize_t read(int handle, void *buffer, size_t bytes);
D*--------------------------------------------------------------------
D read PR 10I 0 ExtProc('read')
D handle 10i 0 value
D buffer * value
D bytes 10U 0 value
D*--------------------------------------------------------------------
D* Read Directory Entry
D*
D* struct dirent *readdir(DIR *dirp)
D*--------------------------------------------------------------------
D readdir PR * EXTPROC('readdir')
D dirp * VALUE
D*--------------------------------------------------------------------
D* Read Value of Symbolic Link
D*
D* int readlink(const char *path, char *buf, size_t bufsiz)
D*--------------------------------------------------------------------
D readlink PR 10I 0 ExtProc('readlink')
D path * value
D buf * value
D bufsiz 10U 0 value
D*--------------------------------------------------------------------
D* Reset Directory Stream to Beginning
D*
D* void rewinddir(DIR *dirp)
D*--------------------------------------------------------------------
D rewinddir PR ExtProc('rewinddir')
D dirp * value
D*--------------------------------------------------------------------
D* Remove Directory
D*
D* int rmdir(const char *path)
D*--------------------------------------------------------------------
D rmdir PR 10I 0 ExtProc('rmdir')
D path * value
D*--------------------------------------------------------------------
D* Get File Information
D*
D* int stat(const char *path, struct stat *buf)
D*--------------------------------------------------------------------
D stat PR 10I 0 ExtProc('stat')
D path * value
D buf * value
D*--------------------------------------------------------------------
D* Make Symbolic Link
D*
D* int symlink(const char *pname, const char *slink)
D*--------------------------------------------------------------------
D symlink PR 10I 0 ExtProc('symlink')
D pname * value
D slink * value
D*--------------------------------------------------------------------
D* Get system configuration variables
D*
D* long sysconf(int name)
D*--------------------------------------------------------------------
D sysconf PR 10I 0 ExtProc('sysconf')
D name 10I 0 Value
D*--------------------------------------------------------------------
D* Set Authorization Mask for Job
D*
D* mode_t umask(mode_t cmask)
D*--------------------------------------------------------------------
D umask PR 10U 0 ExtProc('umask')
D cmask 10U 0 Value
D*--------------------------------------------------------------------
D* Remove Link to File. (Deletes Directory Entry for File, and if
D* this was the last link to the file data, the file itself is
D* also deleted)
D*
D* int unlink(const char *path)
D*--------------------------------------------------------------------
D unlink PR 10I 0 ExtProc('unlink')
D pa|h * Value
D*--------------------------------------------------------------------
D* Set File Access & Modification Times
D*
D* int utime(const char *path, const struct utimbuf *times)
D*--------------------------------------------------------------------
D utime PR 10I 0 ExtProc('utime')
D path * value
D times * value
D*--------------------------------------------------------------------
D* Write to a file
D*
D* ssize_t write(int fildes, const void *buf, size_t bytes)
D*--------------------------------------------------------------------
D write PR 10I 0 ExtProc('write')
D handle 10I 0 value
D buffer * value
D bytes 10U 0 value
Here is a simple example of how to use these APIs:
----------------------------------------------------------------------
* TO COMPILE:
* CRTBNDRPG PGM(xxxxx) SRCFILE(xxx/xxxx) DFTACTGRP(*NO) ACTGRP(*NEW)
*
D/COPY LIBSOR/QRPGLESRC,IFSIO_H
D fd S 10I 0
D Mode S 10U 0
D Flags S 10U 0
D MyFile S 64A
D Char S 1A
D Length S 5P 0
D String S 50A
D Msg S 50A
D Table S 10A
c exsr WriteEx
c exsr ReadEx
c eval *INLR = *On
C*===============================================================
C* Example of Writing/Creating a Stream File
C*===============================================================
csr WriteEx begsr
C*------------------------
C* location of file
c eval MyFile='/QOpenSys/myfile.txt' +x'00'
C* create a file, if it exists "truncate it" to zero bytes.
c eval Flags = O_CREAT + O_TRUNC + O_WRONLY
C* read/write for owner
C* read/write for group
C* (no access to public)
c eval Mode=S_IRUSR+S_IWUSR+S_IRGRP+S_IWGRP
C* open the file, now.
c eval fd = open(%addr(MyFile): Flags: Mode)
C* it failed?]
c if fd < 0
c eval Msg = 'open() failed]'
c dsply Msg
c eval *INLR = *On
c Return
c endif
C* data to write + CR/LF
c eval String = 'ILE Programming is COOL'
c + x'0D25'
c ' ' checkr String Length
C* xlate it to ASCII
C* (optional)
c call 'QDCXLATE'
c parm Length
c parm String
c parm 'QASCII' Table
C* write to the file.
c callp write(fd: %addr(String): Length)
C* close the file
c callp closef(fd)
C*-----------------------
csr Endsr
C*===============================================================
C* Example of Reading From a Stream File
C*===============================================================
csr ReadEx begsr
C*------------------------
C* location of file
c eval MyFile='/QOpenSys/myfile.txt' +x'00'
C* open the file, now.
c eval fd = open(%addr(MyFile): O_RDONLY)
C* it failed?]
c if fd < 0
c eval Msg = 'open() failed]'
c dsply Msg
c eval *INLR = *On
c Return
c endif
c eval Length = 0
c eval String = *blanks
C* read one "line" from
C* the file.
c dou Char = x'0A'
c if Read(fd: %addr(Char): 1) < 1
c Leave
c endif
c if Char<>x'0A' and Char<>x'0D'
c eval Length = Length + 1
c eval %subst(String: Length: 1) = Char
c endif
c enddo
C* Convert to EBCDIC
c if Length > 0
c call 'QDCXLATE'
c parm Length
c parm String
c parm 'QEBCDIC' Table
c endif
C* Show that line
c dsply String
c callp closef(fd)
C*------------------------
Csr endsr
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