Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : PCCAPP.ZIP
Filename : LS.CC

/*
* This file is part of the Choices Operating System
* Developed by: The TAPESTRY Parallel Computing Laboratory
* University of Illinois at Urbana-Champaign
* Department of Computer Science
* 1304 W. Springfield Ave.
* Urbana, IL 61801
*
* Copyright (c) 1987, 1988, 1989, 1990, 1991, 1992
* The University of Illinois Board of Trustees.
* All Rights Reserved.
*
* Author: Lee Lup Yuen ([email protected])
* Project Manager and Principal Investigator: Roy Campbell ([email protected])
*
* Funded by: NSF TAPESTRY Grant No. 1-5-30035, NASA ICLASS Grant
* No. 1-5-25469 and No. NSG1471 and AT&T Metronet Grant No. 1-5-37411.
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for educational, research, and non-profit purposes
* is hereby granted provided that the above copyright notice, the
* original authors names, and this permission notice appear in all such
* copies and supporting documentation; that no charge be made for such
* copies; and that the name of the University of Illinois not be used
* in advertising or publicity pertaining to distribution of the
* software without specific prior written permission. Any entity
* desiring permission to incorporate this software into commercial
* products should contact the Computing Research Laboratory, Department
* of Computer Science, University of Illinois, 1304 W. Springfield
* Avenue, Urbana, IL 61801. The University of Illinois makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/

#include "OutputStream.h"
#include "NameServer.h"
#include "VirtualPCInterface.h"
#include "VirtualPCArgs.h"
#include "String.h"

// Format of a DOS directory entry.
struct DirEntry
{
char internal [21];
unsigned int attribute:8;
unsigned int time:16;
unsigned int date:16;
char size [4]; // Can't use unsigned int here - g++ aligns 32-bit data.
char name [13];
};

void processEntry (DirEntry *entry);
void printEntries ();

int main (int argc, char **)
{
if (argc >= 2)
{
*StandardOutput << "Sorry, ls does not accept any arguments\n" << eor;
return 3;
}
VirtualPCInterface *virtualPC = (VirtualPCInterface *) StandardNameServer
-> lookup ("virtualPCInterface", "VirtualPCInterface");
Assert (virtualPC != 0);
VirtualPCArgs args;
// DOS will store info about directory entries in dirEntry.
DirEntry dirEntry;
// Tell DOS to search for the first dir entry matching "*.*".
args.set (rAX, 0x4e00); // DOS function 0x4e.
args.setConstBuffer (rDS, rDX, "*.*");
args.set (rCX, 0xffff);
args.setDTA ((char *) &dirEntry, sizeof (DirEntry));
int err = virtualPC -> executeVector (DOSVector, &args);
if (err) return 1;
for (;;)
{
// If carry flag is set, then no more files or error.
if (args.get (rFlags) & 1) break;
// We have found a match. Process it.
processEntry (&dirEntry);
// Tell DOS to search for the next matching dir entry.
args.reset ();
args.set (rAX, 0x4f00); // DOS function 0x4f.
args.setDTA ((char *) &dirEntry, sizeof (DirEntry));
err = virtualPC -> executeVector (DOSVector, &args);
if (err) return 2;
}
printEntries ();
return 0;
}

struct StringList
{
char str [13];
StringList *next;
};

StringList *entryNames = 0;

void processEntry (DirEntry *entry)
{
// Process a directory entry before printing it.
// Put entry name into correct upper/lowercase: ordinary files are
// all lowercase, directories are all lowercase except for the first
// letter. Make the whole name lowercase first.
for (char *name = entry -> name; *name != 0; name++)
if (*name >= 'A' && *name <= 'Z') *name = *name - 'A' + 'a';
// If it's a directory, make the first letter uppercase.
name = entry -> name;
if ((entry -> attribute & 16) && *name >= 'a' && *name <= 'z')
*name = *name - 'a' + 'A';
// Add the entry name into a sorted list for printing later.
StringList *newName = new StringList;
strcpy (newName -> str, name);
StringList *s = entryNames, *sPrev = 0;
while (s != 0)
{
if (strcmp (name, s -> str) < 0) break;
sPrev = s;
s = s -> next;
}
if (sPrev == 0)
{
newName -> next = entryNames;
entryNames = newName;
}
else
{
newName -> next = s;
sPrev -> next = newName;
}
}

static char spaces [] = " "; // 14 spaces.

void printEntries ()
{
// Print all the directory entries we have processed.
StringList *s = entryNames;
int col = 0;
while (s != 0)
{
char *name = s -> str;
// Print name and pad it with spaces to make 14 characters.
int spaceCount = 14 - strlen (name);
spaces [spaceCount] = 0;
*StandardOutput << name << spaces;
spaces [spaceCount] = ' ';
s = s -> next;
// Print 5 names in a column.
col = (col + 1) % 5;
if (col == 0) *StandardOutput << "\n" << eor;
}
if (col != 0) *StandardOutput << "\n" << eor;
}