dmake/msdos/find.c

   1 /*
   2     Directory Access Library
   3
   4            FIND.C taken from DIRLIB.C by M. J. Weinstein
   5          Released to public domain 1-Jan-89
   6
   7     The author may be contacted at:
   8     matt@cs.ucla.edu -or- POB 84524, L.A., CA  90073
   9
  10     Modified by dvadura@watdragon.edu to work with dmake.
  11     (nuked the DOS version 2 code, since dmake needs version
  12     3.0 or greater to function).
  13  */
  14
  15
  16 /*
  17  * revision history:
  18  *
  19  *  VER MM/DD/YY    COMMENTS
  20  *  ----    --------    --------
  21  *  0.99    02/24/86    Beta release to INTERNET
  22  */
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <ctype.h>
  27 #include <errno.h>
  28 #include <string.h>
  29 #include <alloc.h>
  30 #include <dos.h>
  31 #include "dosdta.h"
  32
  33 #ifndef MK_FP
  34 #define MK_FP(seg,ofs)  ((void far *) \
  35                (((unsigned long)(seg) << 16) | (unsigned)(ofs)))
  36 #endif
  37 #ifndef FP_SEG
  38 #define FP_SEG(fp)  ((unsigned)((unsigned long)(fp) >> 16))
  39 #endif
  40 #ifndef FP_OFF
  41 #define FP_OFF(fp)  ((unsigned)(fp))
  42 #endif
  43
  44 int find_err;
  45
  46 /*
  47  * get/set dta address
  48  */
  49
  50 static DTA far *
  51 _getsetdta(newdta)
  52 DTA far *newdta;
  53 {
  54     DTA far *olddta;
  55     union REGS r;
  56     struct SREGS s;
  57
  58     /* get old dta */
  59     r.h.ah = 0x2f;
  60     intdos(&r, &r);
  61     segread(&s);
  62     olddta = (DTA far *) MK_FP(s.es, r.x.bx);
  63
  64     /* conditionally set new dta */
  65     if (newdta) {
  66         r.h.ah = 0x1a;
  67         s.ds    = FP_SEG(newdta);
  68         r.x.dx  = FP_OFF(newdta);
  69         intdosx(&r, &r, &s);
  70     }
  71
  72     return olddta;
  73 }
  74
  75 /*
  76  * dos findfirst
  77  */
  78
  79 DTA *
  80 findfirst(name, dta)
  81 char *name;
  82 DTA  *dta;
  83 {
  84     union REGS r;
  85     struct SREGS s;
  86     DTA far *dtasave;
  87     char far *nmp = (char far *)name;
  88
  89     dtasave = _getsetdta((DTA far *)dta);
  90
  91     /* do directory lookup */
  92     segread(&s);
  93     r.h.ah  = 0x4e;
  94     r.x.cx  = 0x10;
  95     r.x.dx  = FP_OFF(nmp);
  96     s.ds    = FP_SEG(nmp);
  97     intdosx(&r, &r, &s);
  98     /* restore dta */
  99     _getsetdta(dtasave);
 100     find_err = r.x.ax;
 101     if (r.x.cflag)
 102         return(NULL);
 103
 104     return dta;
 105 }
 106
 107 /*
 108  * dos findnext
 109  */
 110
 111 DTA *
 112 findnext(dta)
 113 DTA *dta;
 114 {
 115     union REGS r;
 116     DTA far *dtasave;
 117
 118     dtasave = _getsetdta((DTA far *)dta);
 119
 120     /* do directory lookup */
 121     r.h.ah = 0x4f;
 122     intdos(&r, &r);
 123     /* restore old dta */
 124     _getsetdta(dtasave);
 125     find_err = r.x.ax;
 126     if (r.x.cflag)
 127         return(NULL);
 128
 129     return dta;
 130 }