mem.zip_MEM_zip

/* MEM.C --walks DOS MCB chain(s) : simple version */ # include <stdio.h> # include <stdlib.h> # include <ctype.h> # include <string.h> # include <dos.h> typedef unsigned char BYTE; typedef unsigned short WORD; typedef unsigned long ULONG; typedef enum {FALSE,TRUE} BOOL; typedef void far *FP; #define MCB_FM_SEG(seg) ((seg)-1) #define IS_PSP(mcb) (FP_SEG(mcb)+1==(mcb)->owner) #define ENV_FM_PSP(psp_seg) *((WORD far *)MK_FP(psp_seg,0x2c)) #pragma pack (1) typedef struct { BYTE type; /* M=in chain , Z=at end */ WORD owner; /* PSP of the owner */ WORD size; /* in 16-byte paragraphs */ BYTE unused [3]; BYTE dos4 [8]; } MCB; void fail (char *s) {puts (s);exit(1);} MCB far *get_mcb (void) { __emit__(0xB4,0x52); /* MOV AH,52 */ __emit__(0xCD,0x21); /* INT 21 */ __emit__(0x26); /* ES: */ __emit__(0x8B,0x57,0xFE); /* MOV DX,[BX-02] */ __emit__(0x31,0xC0); /* XOR AX,AX */ } unsigned fstrlen (char far *s) { unsigned len = 0; while (*s++) len ++; return len; } char far *env(MCB far *mcb) { char far *e; unsigned env_mcb; unsigned env_owner; if (IS_PSP(mcb)) e=MK_FP (ENV_FM_PSP(mcb->owner),0); else return (char far *) 0; env_mcb = MCB_FM_SEG (FP_SEG(e)); env_owner = ((MCB far *)MK_FP(env_mcb,0))->owner; return (env_owner==mcb->owner)?e:(char far *)0; } char far *progname_fm_psp (unsigned psp) { char far *e; unsigned len; if (!(e=env(MK_FP(MCB_FM_SEG(psp),0)))) return (char far *)0; if (_osmajor>=3) { do e+=(len=fstrlen(e))+1; while (len); if ((*((signed far *)e)>=1)&&(*((signed far *)e)<10)) { e+=sizeof (signed); if (isalpha(*e)) return e; } } return (char far *) 0; } void display_progname (MCB far *mcb) { char far *s; if (IS_PSP(mcb)) if (s=progname_fm_psp ((FP_SEG(mcb)+1))) printf (" %Fs",s); } BOOL belongs (void far *vec,unsigned start,unsigned size) { unsigned seg = FP_SEG (vec) + (FP_OFF(vec)>>4); return (seg>=start)&&(seg<=(start+size)); } void display_cmdline (MCB far *mcb) { int len=*((BYTE far *)MK_FP(mcb->owner,0x80)); char far *cmdline=MK_FP(mcb->owner,0x81); printf ("%.*Fs",len,cmdline); } void display_vectors (MCB far *mcb) { static void far **vec=(void far **) 0; WORD vec_seg; int i; int did_one=0; if (!vec) { if (!(vec=calloc(256,sizeof(void far *)))) fail ("insufficient memory ."); for (i=0;i<256;i++) vec[i]=getvect(i); } for (i=0;i<256;i++) if (vec[i]&&belongs(vec[i],FP_SEG (mcb),mcb->size)) { if (!did_one) {did_one++; printf ("[");} printf ("%02X ",i); vec[i]=0; } if (did_one) printf ("]"); } void display (MCB far *mcb) { static void far *vect_2e=(void far *)0; unsigned env_seg; printf ("%04X %04X %04X(%6lu) ", FP_SEG (mcb),mcb->owner,mcb->size,(long)mcb->size<<4); if (IS_PSP(mcb)) { void far *e=env (mcb); if (env_seg = FP_SEG(e)) printf ("%04X",env_seg); else printf (" "); display_progname (mcb); } if (!vect_2e) vect_2e = getvect (0x2e); if (!mcb->owner) printf ("free "); else if (mcb->owner == 8) printf ("config "); else if (belongs (vect_2e,FP_SEG(mcb),mcb ->size)) printf (" %s",getenv ("COMSPEC")); if (IS_PSP(mcb)) display_cmdline (mcb); display_vectors (mcb); printf ("\n"); } void walk (MCB far *mcb) { printf ("Seg Owner Size Env\n"); for (;;) switch (mcb->type) { case 'M' : display (mcb); mcb=MK_FP (FP_SEG (mcb)+mcb->size+1,0); break; case 'Z' : display (mcb); return; default : fail ("error in MCB chain "); } } main (int argc,char *argv[]) { if (argc<2) walk (get_mcb()); else { unsigned seg; sscanf (argv[1],"%04X",&seg); walk (MK_FP(seg,0)); } printf (" total memory %dK bytes\n",biosmemory()); return 0; }