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| 31 |
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31 |
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/* rewires my parent pointer, uninstalls rmod let DOS terminate me, UNLESS
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/* rewires my parent pointer, uninstalls rmod let DOS terminate me, UNLESS
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* my parent is unknown */
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* my parent is unknown */
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void sayonara(struct rmod_props far *rmod) {
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34 |
void sayonara(struct rmod_props far *rmod) {
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unsigned short rmodseg = rmod->rmodseg;
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unsigned short rmodseg = rmod->rmodseg;
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unsigned long *myint22 = (void *)0x0A;
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unsigned long *myparent = (void *)0x0A;
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unsigned short *myparent = (void *)0x16;
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unsigned short far *rmodenv_ptr = MK_FP(rmodseg, RMOD_OFFSET_ENVSEG);
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unsigned short far *rmodenv_ptr = MK_FP(rmodseg, RMOD_OFFSET_ENVSEG);
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unsigned short rmodenv = *rmodenv_ptr;
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unsigned short rmodenv = *rmodenv_ptr;
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/* detect "I am the origin shell" situations */
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/* detect "I am the origin shell" situations */
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if (rmod->flags & FLAG_PERMANENT) return; /* COMMAND.COM /P */
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if (rmod->flags & FLAG_PERMANENT) return; /* COMMAND.COM /P */
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if ((rmod->origparent >> 16) == 0xffff) return; /* original parent seg set to 0xffff (DOS-C / FreeDOS) */
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if ((rmod->origint22 >> 16) == 0xffff) return; /* original int22h seg set to 0xffff (DOS-C / FreeDOS) */
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if (rmod->origenvseg == 0) return; /* no original environment (MSDOS 5/6) */
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if (rmod->origenvseg == 0) return; /* no original environment (MSDOS 5/6) */
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/* set my int 22h handler back to its original value */
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*myint22 = rmod->origint22;
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48 |
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/* set my parent back to original value */
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49 |
/* set my parent back to its original value */
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*myparent = rmod->origparent;
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*myparent = rmod->origparent;
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_asm {
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_asm {
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/* free RMOD's code segment and env segment */
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/* free RMOD's code segment and env segment */
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mov ah, 0x49 /* DOS 2+ -- Free Memory Block */
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mov ah, 0x49 /* DOS 2+ -- Free Memory Block */
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