Thanks! Charles
-----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Bernd Oppolzer Sent: Tuesday, May 01, 2012 6:09 PM To: [email protected] Subject: Re: Does C/LE open of DD:ddname(member) use SVC 99 or FIND? Thank you! Here is an excerpt of a C program which reads a directory of a PDS and inserts the member names into an AVL tree (the insert is not shown, it is done by a function call - see below). Kind regards Bernd static int lese_memberliste (char *parm_infile, baumMEMknoten **pres) /************************************************/ /* Funktion zum Lesen einer Memberliste */ /* einer PO-Datei; die Membernamen werden */ /* in einen AVL-Baum eingetragen */ /************************************************/ { FILE *direct; char buf [256]; int x; char *cp; int laenge; unsigned long ttrc; int ttr; int anz_bytes; int eof; int rc = 0; char mem_high [8]; baumMEMknoten *proot = NULL; baumMEMknoten *pneu; int hchanged; membname m; eof = 0; memset (mem_high, 0xff, 8); /************************************************/ /* raus, wenn Directory nicht aufgeht */ /************************************************/ direct = fopen (parm_infile, "rb"); if (direct == NULL) RETURN_VALUE 8; for (;;) { /************************************************/ /* naechsten Directory-Block einlesen */ /************************************************/ memset (buf, 0x00, 256); x = fread (buf, 1, 256, direct); if (x == 0) break; #ifdef TEST printf ("[cp2970] \n"); printf ("[cp2970] Rueckgabe von fread = %d\n", x); printf ("[cp2970] \n"); dump (buf, buf + x - 1, stdout); #endif cp = buf + 2; laenge = *((short *) buf) - 2; while (laenge > 0) { /************************************************/ /* naehere Info hierzu in den IBM-Brosch. */ /* zum Aufbau der PO-Directories. */ /************************************************/ if (memcmp (cp, mem_high, 8) == 0) { eof = 1; break; } /************************************************/ /* Laenge des Eintrags in Halbworten steht */ /* in den Bits 3 bis 7 des TTRC-Wortes */ /************************************************/ ttrc = *((unsigned long *) (cp + 8)); ttr = ttrc >> 8; anz_bytes = (ttrc & 0x1f) * 2; #ifdef TEST printf ("[cp2970] Member %-8.8s TTR %06X Laenge/Bytes %d\n", cp, ttr, anz_bytes); #endif if (memcmp (cp, "ED", 2) == 0) { memcpy (m.name, cp, 8); hchanged = 0; pneu = baumMEMsuche (&m, &proot, &hchanged, 1); pneu -> obj = atoi (cp + 2); } cp += (anz_bytes + 12); laenge -= (anz_bytes + 12); } if (eof) break; } fclose (direct); *pres = proot; RETURN_VALUE rc; } Am 01.05.2012 23:52, schrieb John Gilmore: > The point here is not what some particular routine oor utility may do > or permit. It is what can be done ab initio by an programmer who > wants to do it using the HLASM or some particular SLPL . > > z/OS MVS does permit one to open a PDS as a PS data set in a routine > written in assembly language or PL/I, and what one then gets with > successive reads are its successive directory blocks. > > I have done this many times without incident, but I do not of course > recommend it to novices. > > I have not myself done it in C; but Bernd Oppolzer is a careful, > highly reliable reporter of his experience; and I am thus sure that it > can be done in C too. > > John Gilmore, Ashland, MA 01721 - USA > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
