/* -> c.ckafio
 */

char *ckzv = "Arthur file support, 25 June 87";

/* C K A F I O  --  Kermit file system support for Arthur */

/*
 Author: Frank da Cruz (SY.FDC@CU20B),
 Columbia University Center for Computing Activities, January 1985.
 Copyright (C) 1985, Trustees of Columbia University in the City of New York.
 Permission is granted to any individual or institution to use, copy, or
 redistribute this software so long as it is not sold for profit,
 provided this copyright notice is retained. 
 Arthur version: Graham Toal/Acorn VLSI Tools Group (c) Acorn Computers Plc.
*/

/* Includes */

#include "ckcker.h"         /* Kermit definitions */
#include "ckcdeb.h"         /* Typedefs, debug formats, etc */
#include <stdio.h>          /* Standard i/o */
#ifdef PANOS
#include <ascii.h>
#endif
#ifdef ANSI
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "h.ckuusr"
#include "h.ckafio"
#include "h.ckamis"
#endif
#ifdef ARTHUR
#include "h.plib"
#include "h.dir"
#endif
#define NL LF

char *ckzsys = " Acorn Arthur";

/* Definitions of some Arthur system commands - needs changing */

char *DIRCMD = "cat ";                      /* For directory listing */
char *DELCMD = "delete ";                   /* For file deletion */
char *TYPCMD = "type ";                     /* For typing a file */
char *PWDCMD = "pwd ";                      /* For saying where I am */
char *CWDCMD = "dir ";                      /* For selecting new dir */

char *SPACMD = "run du ";       /* Space/quota of current directory */
char *SPACM2 = "run du ";       /* For space in specified directory */
char *WHOCMD = "users ";      /* For seeing who's logged in */

/*
  Functions (n is one of the predefined file numbers from ckermi.h):

   zopeni(n,name)   -- Opens an existing file for input.
   zopeno(n,name)   -- Opens a new file for output.
   zclose(n)        -- Closes a file.
   zchin(n,&c)      -- Gets the next character from an input file.
   zsout(n,s)       -- Write a null-terminated string to output file,
                        buffered.
   zsoutl(n,s)      -- Like zsout, but appends a line terminator.
   zsoutx(n,s,x)    -- Write x characters to output file, unbuffered.
   zchout(n,c)      -- Add a character to an output file, unbuffered.
   zchki(name)      -- Check if named file exists and is readable,
                       return size.
   zchko(name)      -- Check if named file can be created.
   znewn(name,s)    -- Make a new unique file name based on the given name.
   zdelet(name)     -- Delete the named file.
   zxpand(string)   -- Expands the given wildcard string into a list of files.
   znext(string)    -- Returns the next file from the list in "string".
   zxcmd(cmd)       -- Execute the command in a lower fork.
   zclosf()         -- Close input file associated with zxcmd()'s lower fork.
   zrtol(n1,n2)     -- Convert remote filename into local form.
   zltor(n1,n2)     -- Convert local filename into remote form.
   zchdir(dirnam)   -- Change working directory.
   zhome()          -- Return pointer to home directory name string.
   zkself()         -- Kill self, log out own job.
 */

/* Declarations */
#define NOFILE -99

int fp[ZNFILS]   = { NOFILE, NOFILE, NOFILE, NOFILE, NOFILE, NOFILE, NOFILE,
NOFILE, NOFILE };
int isout[ZNFILS]= { 0, 0, 0, 0, 0, 0, 0, 0, 0 };

#ifdef PANOS
extern int GetFileInformation () asm;
extern int EndOfFile() asm;
extern int SWriteByte() asm; 
extern int XSWriteByte() asm;
extern int SBlockWrite() asm;
extern int XSBlockWrite() asm;
extern int SReadByte() asm;
extern int XSReadByte() asm;
extern int BytesOutstanding() asm;
extern int XBytesOutstanding() asm;
extern int XFindInput() asm;
extern int XFindOutput() asm;
extern int XCloseStream() asm;
extern int XSFlushOutput() asm;
#endif

#define ZOBUFSIZ 4096

static char zobuf[ZOBUFSIZ];
int zohandle = NOFILE, zosize = 0;

#ifdef ANSI
void
#endif
Buffer(stream) int stream; /* select this stream to be buffered */
{
#ifdef ANSI
extern void BFlush( int );
#endif

  if (zohandle != NOFILE) BFlush(zohandle);
  zohandle = stream; zosize = 0;
}

#ifdef ANSI
void
#endif
BFlush(stream) int stream; {
  if (stream == zohandle) {
    if (zosize) { XSBlockWrite(stream, zosize, zobuf); zosize = 0; }
  }
  XSFlushOutput(stream);
}

#ifdef ANSI
void
#endif
BWrite(stream, num, data) int stream, num; char *data; 
{
  if (stream == zohandle) {
    while (num--) {
      zobuf[zosize++] = *data++;
      if (zosize >= ZOBUFSIZ) BFlush(stream);
    }
  }
  else XSBlockWrite(stream, num, data);
}

/***************************************************************/
/*  Z K S E L F  --  Kill Self: log out own job, if possible.  */
/***************************************************************/

#ifdef ANSI
int
#endif
zkself() { return(0); }

/******************************************************/
/*  Z O P E N I  --  Open an existing file for input. */
/******************************************************/

#ifdef ANSI
int
#endif
zopeni(n,name) int n; char *name; {
  debug(F111," zopeni",name,n);
  debug(F101,"  fp","", fp[n]);
  if (chkfn(n) != 0) return(0);
  isout[n] = 0;
  if (n == ZSYSFN) {            /* Input from a system function? */
    debug(F110," invoking zxcmd",name,0);
    return(zxcmd(name));        /* Try to fork the command */
  }
  if (n == ZSTDIO) {            /* Standard input? */
    /* no easy way to check in Arthur ?
    if (isatty(0)) { ermsg("Terminal input not allowed"); return(0); }
    */
    fp[ZIFILE] = XFindInput("INPUT:", 6); return(1);
  }
  fp[n] = XFindInput(name, strlen(name)); isout[n] = 0;
  debug(F111," zopeni", name, fp[n]);
  if (fp[n] < 0) { perror("zopeni"); fp[n] = NOFILE; }
  return(1);
}

/**************************************************/
/*  Z O P E N O  --  Open a new file for output.  */
/**************************************************/

#ifdef ANSI
int
#endif
zopeno(n,name) int n; char *name; {
  if (chkfn(n)) return(0);
  isout[n] = 1;
  if (n == ZCTERM) { fp[ZOFILE] = XFindOutput("VDU:", 4); return(1); }
  if (n == ZSTDIO) { fp[ZOFILE] = XFindOutput("OUTPUT:", 7); return(1); }
  fp[n] = XFindOutput(name, strlen(name));
  if (n == ZOFILE) Buffer(fp[n]);
  if (fp[n] < 0) { perror("zopeno can't open"); fp[n] = NOFILE; }
  return((fp[n] >= 0) ? 1 : 0);
}

/********************************************/
/*  Z C L O S E  --  Close the given file.  */
/********************************************/

#ifdef ANSI
int
#endif
zclose(n) int n; {
  if (chkfn(n) < 1) return(0);  /* Check range of n */
  if ((n == ZIFILE) && (fp[ZSYSFN] >= 0) ) { zclosf(); return(1); }
  if (fp[n] >= 0) { 
    if (isout[n]) { BFlush(fp[n]); }
    XCloseStream(fp[n]); 
  }
  fp[n] = NOFILE; isout[n] = 0; return(1);
}

/************************************************************************/
/*  Z C H I N  --  Get a character from the input file.                 */
/*  Returns -1 if EOF, 0 otherwise with character returned in argument  */
/************************************************************************/

#ifdef ANSI
int
#endif
zchin(n,c) int n; char *c;
{ int a;
  if (chkfn(n) < 1) return(-1);
  if (EndOfFile(fp[n]) == 1) return(-1);
  a = SReadByte(fp[n]);
  if (a < 0) return(-1);
  *c = a & 0377;
  return(0);
}

/****************************************************************/
/*  Z S O U T  --  Write a string to the given file, buffered.  */
/****************************************************************/

#ifdef ANSI
int
#endif
zsout(n,s) int n; char *s; {
  if (chkfn(n) < 1) return(-1);
  BWrite(fp[n], strlen(s), s); return(0);
}

/***************************************************************************/
/*  Z S O U T L  --  Write string to file, with line terminator, buffered  */
/***************************************************************************/

#ifdef ANSI
int
#endif
zsoutl(n,s) int n; char *s; {
  if (chkfn(n) < 1) return(-1);
  zsout(n,s); zchout(n,NL); return(0);
}

/**************************************************************/
/*  Z S O U T X  --  Write x characters to file, unbuffered.  */
/**************************************************************/

#ifdef ANSI
int
#endif
zsoutx(n,s,x) int n, x; char *s; {
  BWrite(fp[n], x, s); BFlush(fp[n]); return(0);
}

/***************************************************************************/
/*  Z C H O U T  --  Add a character to the given file.                    */
/*  Should return 0 or greater on success, -1 on failure (e.g. disk full)  */
/***************************************************************************/

#ifdef ANSI
int
#endif
zchout(
#ifdef ANSI
int n, char c)
#else
n,c) int n; char c;
#endif
{
  BWrite(fp[n], 1, &c); return(0);
}

/******************************************************************/
/*  C H K F N  --  Internal function to verify file number is ok  */
/*                                                                */
/* Returns:                                                       */
/*  -1: File number n is out of range                             */
/*   0: n is in range, but file is not open                       */
/*   1: n in range and file is open                               */
/******************************************************************/

#ifdef ANSI
int
#endif
chkfn(n) int n; {
    switch (n) {
    case ZCTERM:
    case ZSTDIO:
    case ZIFILE:
    case ZOFILE:
    case ZDFILE:
    case ZTFILE:
    case ZPFILE:
    case ZSFILE:
    case ZSYSFN: break;
    default:
        debug(F101,"chkfn: file number out of range","",n);
        return(-1);
    }
    return( (fp[n] == NOFILE) ? 0 : 1 );
}

/************************************************************************/
/*  Z C H K I  --  Check if input file exists and is readable           */
/*                                                                      */
/*  Returns:                                                            */
/*   >= 0 if the file can be read (returns the size).                   */
/*     -1 if file doesn't exist or can't be accessed,                   */
/*     -2 if file exists but is not readable (e.g. a directory file).   */
/*     -3 if file exists but protected against read access.             */
/*                                                                      */
/*                                                                      */
/* For Berkeley Unix, a file must be of type "regular" to be readable.  */
/* Directory files, special files, and symbolic links are not readable. */
/************************************************************************/

#ifndef ANSI
struct FileData {int loadaddr, execaddr, length, attrib;};

struct BTim {int low, high;};
#endif

long zchki(name) char *name; {
  struct FileData fileinfo;
  struct BTim timeinfo;
  int rc;
  fileinfo.length = -1;
  rc = GetFileInformation(&fileinfo, &timeinfo, name, strlen(name));
  if (rc == 2) return(-2);
  if (rc < 0)  return(-1);
  return(fileinfo.length);
}

/****************************************************************************/
/*  Z C H K O  --  Check if output file can be created                      */
/*                                                                          */
/* Returns -1 if write permission for the file would be denied, 0 otherwise.*/
/****************************************************************************/

#ifdef ANSI
int
#endif
zchko(name) char *name; { return(0); }

/*********************************************/
/*  Z D E L E T  --  Delete the named file.  */
/*********************************************/

#ifdef ANSI
int
#endif
zdelet(name) char *name; {
  char cmdstr [512];
  char *prefix, *suffix;
  char *cp;
  prefix = DELCMD; suffix = name;
  if (prefix == NULL || *prefix == '\0') return(0);
  for (cp = cmdstr; *prefix != '\0'; *cp++ = *prefix++) ;
#ifdef ANSI
  while ( (*cp++ = *suffix++) != '\0' ) ;
#else
  while (*cp++ = *suffix++) ;
#endif
  system(cmdstr);
  return(1);
}

#ifdef PANOS
/*******************************************************************/
/*  Z R T O L  --  Convert remote filename into local form         */
/*  For Arthur, this means changing dots into dashes.              */
/*******************************************************************/

#ifdef ANSI
static void
#endif
editfname(s,oldc,newc,newlast) char *s; char oldc,newc,newlast;
/*  changes occurrences of oldc in string s to newc, except for  */
/*  last occurrence which gets changed to newlast                */
{ char *p,*pos;
  pos = 0;
  for (p = s; *p; ++p) if (*p == oldc) { *p = newc; pos = p; }
  if (pos) *pos = newlast;
}
       
#ifdef ANSI
void
#endif
zrtol(remote,local) char *remote,*local; 
{ char *ans = local;
#ifdef ANSI
  while ( (*local++ = *remote++) != '\0' );
#else
  while (*local++ = *remote++);
#endif
  editfname(ans, '-', '=', '=');
  editfname(ans, '.', '_', '-');
  editfname(ans, '/', '.', '.');
}

/*****************************************************************/
/*  Z L T O R  --  Local TO Remote                               */
/*  Convert filename from local format to common (remote) form.  */
/*****************************************************************/

#ifdef ANSI
void
#endif
zltor(local,remote) char *local, *remote;
{ char *ans = remote;
#ifdef ANSI
  while ( (*remote++ = *local++) != '\0' );
#else
  while (*remote++ = *local++);
#endif
  editfname(ans, '/', '=', '=');
  editfname(ans, '.', '/', '/');
  editfname(ans, '-', '-', '.');
}    
#endif


#ifdef ARTHUR
/*******************************************************************/
/*  Z R T O L  --  Convert remote filename into local form         */
/*  For Arthur, this means changing dots into dashes.              */
/*******************************************************************/

#ifdef ANSI
static void
#endif
editfname(s,oldc,newc,newlast) char *s; char oldc,newc,newlast;
/*  changes occurrences of oldc in string s to newc, except for  */
/*  last occurrence which gets changed to newlast                */
{ char *p,*pos;
  pos = 0;
  for (p = s; *p; ++p) if (*p == oldc) { *p = newc; pos = p; }
  if (pos) *pos = newlast;
}
       
#ifdef ANSI
void
#endif
zrtol(remote,local) char *remote,*local; 
{ char *ans = local;
#ifdef ANSI
  while ( (*local++ = *remote++) != '\0' );
#else
  while (*local++ = *remote++);
#endif
  editfname(ans, '-', '=', '=');
  editfname(ans, '.', '_', '-');
  editfname(ans, '/', '.', '.');
}

/*****************************************************************/
/*  Z L T O R  --  Local TO Remote                               */
/*  Convert filename from local format to common (remote) form.  */
/*****************************************************************/

#ifdef ANSI
void
#endif
zltor(local,remote) char *local, *remote;
{ char *ans = remote;
#ifdef ANSI
  while ( (*remote++ = *local++) != '\0' );
#else
  while (*remote++ = *local++);
#endif
  editfname(ans, '/', '=', '=');
  editfname(ans, '.', '/', '/');
  editfname(ans, '-', '-', '.');
}    
#endif

/***************************************/
/*  Z C H D I R  --  Change directory  */
/***************************************/

#ifdef ANSI
int
#endif
zchdir(dirnam) char *dirnam; {
char cmdstr [512];
char *prefix, *suffix;
  char *cp;
  prefix = CWDCMD; suffix = dirnam;
  if (prefix == NULL || *prefix == '\0') return(0);
  for (cp = cmdstr; *prefix != '\0'; *cp++ = *prefix++) ;
#ifdef ANSI
  while ( (*cp++ = *suffix++) != '\0' ) ;
#else
  while (*cp++ = *suffix++) ;
#endif
  system(cmdstr);
  return(1);
}

/************************************************************/
/*  Z H O M E  --  Return pointer to user's home directory  */
/************************************************************/
static char *myhome = "&";
char *zhome() { return(myhome); }

/****************************************************************************/
/*  Z X C M D -- Run a system command so its output can be read like a file */
/****************************************************************************/

#ifdef ANSI
int
#endif
zxcmd(comand) char *comand; {
char *redirect = "{ > kerm-tmp }";
char cmdstr [512];
char *prefix, *suffix;
  char *cp;
  prefix = comand; suffix = redirect;
  if (prefix == NULL || *prefix == '\0') return(0);

  for (cp = cmdstr; *prefix != '\0'; *cp++ = *prefix++) ;

#ifdef ANSI
  while ( (*cp++ = *suffix++) != '\0' ) ;
#else
  while (*cp++ = *suffix++) ;
#endif

  fp[ZSYSFN] = XFindOutput("kerm-tmp", 8);
  XCloseStream(fp[ZSYSFN]); fp[ZSYSFN] = NOFILE;
  /* ensure it is empty in case not written to! */

  if( (strncmp(comand,SPACMD,strlen(SPACMD))==0) ||
      (strncmp(comand,SPACM2,strlen(SPACM2))==0) )
    du("kerm-tmp");
  else
    system(cmdstr);


  fp[ZIFILE] = fp[ZSYSFN] = XFindInput("kerm-tmp", 8);
  return(1);
}

/****************************************************************************/
/*  Z C L O S F  - wait for the child fork to terminate and close the pipe. */
/****************************************************************************/

#ifdef ANSI
int
#endif
zclosf() {
  if (fp[ZSYSFN] >= 0) XCloseStream(fp[ZSYSFN]);
  fp[ZIFILE] = fp[ZSYSFN] = NOFILE;
  return(1);
}

/****************************************************************************/
/*  Z X P A N D  --  Expand a wildcard string into an array of strings      */
/*                                                                          */
/*  Returns the number of files that match fn1, with data structures set up */
/*  so that first file (if any) will be returned by the next znext() call.  */
/****************************************************************************/

#ifdef PANOS
static int countwild, bfptr;
static char namebuff[4096];

addfn(fn, len, arg) char *fn; int len, arg; {
  int rslt;
  while (namebuff[bfptr++] = *fn++) ;
  rslt = 0;
  /********************************************************************/
  /*  we want to pass this to be called from Modula-2, which doesn't  */
  /*  expect to have to unwind the stack: this is horrible.           */
  /********************************************************************/
  asm { MOVD rslt, 0; EXIT #0; RXP #12; } 
}

static int
addfn(fn, len, arg) char *fn; int len, arg; {
#ifdef ANSI
  while ( (namebuff[bfptr++] = *fn++) != '\0' ) ;
#else
  while (namebuff[bfptr++] = *fn++) ;
#endif
  return 0;
}

extern int Expand() asm;

int
zxpand(fn) char *fn; {
  bfptr = 0;
  countwild = Expand(fn, strlen(fn),
                     &addfn, /* state arg = */ 42,
                     /* target is dir = false */ 0);
  namebuff[bfptr] = '\0';
  bfptr = 0;
  return(countwild);
}

/**************************************************************************/
/*  Z N E X T  --  Get name of next file from list created by zxpand().   */
/*                                                                        */
/* Returns >0 if there's another file, with its name copied into the      */
/* arg string, or 0 if no more files in list.                             */
/**************************************************************************/

#ifdef ANSI
int
#endif
znext(fn) char *fn; {
#ifndef ANSI
  int i = 0;
#endif
  char *thisone;
  if (countwild-- > 0) {
    if (namebuff[bfptr] == '\0') {
      printf("Internal error: eos in znext\n"); return(0);
    }
    thisone = &namebuff[bfptr];
    while (namebuff[bfptr++]) ;
    strcpy(fn, thisone);
    return(1);
  } 
  else return(0);
}
#endif


#ifdef ARTHUR


#define MAXWLD 50                      /* Maximum wildcard filenames */
static int fcount;                     /* Number of files in wild group */
static char *mtchs[MAXWLD],            /* Matches found for filename */
     **mtchptr;                                /* Pointer to current match */

int
zxpand(fn) char *fn; {
extern int fgen( char *, char *[], int );

    fcount = fgen(fn,mtchs,MAXWLD);    /* Look up the file. */
    if (fcount > 0) {
       mtchptr = mtchs;                /* Save pointer for next. */
    }
    debug(F111,"zxpand",mtchs[0],fcount);
    return(fcount);
}

/*  Z N E X T  --  Get name of next file from list created by zxpand(). */
/*
 Returns >0 if there's another file, with its name copied into the arg string,
 or 0 if no more files in list.
*/
int
znext(fn) char *fn; {
    if (fcount-- > 0) strcpy(fn,*mtchptr++);
    else *fn = '\0';
    debug(F111,"znext",fn,fcount+1);
    return(fcount+1);
}

#endif


/*******************************************************/
/*  Z N E W N  --  Make a new name for the given file  */
/*******************************************************/

#ifdef ANSI
void
#endif
znewn(fn,s) char *fn, **s; {
  static char buf[256];
  int i = 0;
#ifdef ANSI
  while ( (buf[i] = fn[i]) != '\0' ) i++;
#else
  while (buf[i] = fn[i]) i++;
#endif
  *s = buf;
}

/* Directory Functions for Unix, written by Jeff Damens, CUCCA, 1984. */

/*
 * The path structure is used to represent the name to match.
 * Each slash-separated segment of the name is kept in one
 * such structure, and they are linked together, to make
 * traversing the name easier.
 */

struct path {
              char npart[MAXNAMLEN];   /* name part of path segment */
              struct path *fwd;                /* forward ptr */
            };

#define SSPACE 2000                   /* size of string-generating buffer */
static char sspace[SSPACE];           /* buffer to generate names in */
static char *freeptr,**resptr;        /* copies of caller's arguments */
static int remlen;                    /* remaining length in caller's array*/
static int numfnd;                    /* number of matches found */
static char nambuf[MAXNAMLEN+1];       /* Buffer for a filename */

extern void traverse( struct path *, char *, char *);
extern void addresult( char * );
int iswild( char * );
extern int match( char *, char * );

/*
 * splitpath:
 *  takes a string and splits the slash-separated portions into
 *  a list of path structures.  Returns the head of the list.  The
 *  structures are allocated by malloc, so they must be freed.
 *  Splitpath is used internally by the filename generator.
 *
 * Input: A string.
 * Returns: A linked list of the slash-separated segments of the input.
 */

struct path *
splitpath(p)
char *p;
{
 struct path *head,*cur,*prv;
 int i;
 head = prv = NULL;
/* if (*p == '$') p++;*/            /* skip leading slash */
/* if (*p == ':') p+=2;*/           /* skip drive spec */
 while (*p != '\0')
 {
   cur = (struct path *) malloc(sizeof (struct path));
   debug(F101,"splitpath malloc","",(int)cur);
   if (cur == NULL) fatal("malloc fails in splitpath()");
   cur -> fwd = NULL;
   if (head == NULL) head = cur;
   else prv -> fwd = cur;       /* link into chain */
   prv = cur;
   for (i=0; i < MAXNAMLEN && *p != '.' && *p != '\0'; i++)
     cur -> npart[i] = *p++;
   cur -> npart[i] = '\0';      /* end this segment */
   if (i >= MAXNAMLEN) while (*p != '.' && *p != '\0') p++;
   if (*p == '.') p++;
 }
 return(head);
}

/*
 * fgen:
 *  This is the actual name generator.  It is passed a string,
 *  possibly containing wildcards, and an array of character pointers.
 *  It finds all the matching filenames and stores them into the array.
 *  The returned strings are allocated from a static buffer local to
 *  this module (so the caller doesn't have to worry about deallocating
 *  them); this means that successive calls to fgen will wipe out
 *  the results of previous calls.  This isn't a problem here
 *  because we process one wildcard string at a time.
 *
 * Input: a wildcard string, an array to write names to, the
 *        length of the array.
 * Returns: the number of matches.  The array is filled with filenames
 *          that matched the pattern.  If there wasn't enough room in the
 *         array, -1 is returned.
 * By: Jeff Damens, CUCCA, 1984.
 */

int
fgen(pat,resarry,len)
char *pat,*resarry[];
int len;
{
 struct path *head;
 char scratch[100],*sptr;

 head = splitpath(pat);

 if ( *pat == '.' )
 {
  scratch[0] = '.';
  sptr = scratch+1;
 }
 else
 {
/*  strcpy(scratch,"");*/
  scratch[0] = '\0';
  sptr = scratch/*+2*/;
 }                                     /* init buffer correctly */
 numfnd = 0;                            /* none found yet */
 freeptr = sspace;                     /* this is where matches are copied */
 resptr = resarry;                     /* static copies of these so*/
 remlen = len;                         /* recursive calls can alter them */
 traverse(head,scratch,sptr);          /* go walk the directory tree */
 for (; head != NULL; head = head -> fwd)
   free(head);                         /* return the path segments */
 return(numfnd);                       /* and return the number of matches */
}

/* traverse:
 *  Walks the directory tree looking for matches to its arguments.
 *  The algorithm is, briefly:
 *   If the current pattern segment contains no wildcards, that
 *   segment is added to what we already have.  If the name so far
 *   exists, we call ourselves recursively with the next segment
 *   in the pattern string; otherwise, we just return.
 *
 *   If the current pattern segment contains wildcards, we open the name
 *   we've accumulated so far (assuming it is really a directory), then read 
 *   each filename in it, and, if it matches the wildcard pattern segment, add
 *   that filename to what we have so far and call ourselves recursively on the
 *   next segment.
 *
 *   Finally, when no more pattern segments remain, we add what's accumulated
 *   so far to the result array and increment the number of matches.
 *
 * Input: a pattern path list (as generated by splitpath), a string
 *       pointer that points to what we've traversed so far (this
 *       can be initialized to "/" to start the search at the root
 *       directory, or to "./" to start the search at the current
 *       directory), and a string pointer to the end of the string
 *       in the previous argument.
 * Returns: nothing.
 */

void
traverse(pl,sofar,endcur)
struct path *pl;
char *sofar,*endcur;
{
 DIR *fd;
 struct dirent dir_entry;
 struct dirent *dirbuf = &dir_entry;

 struct FileData fileinfo;
 struct BTim timeinfo;
 int rc;
 int stamped;

 if (pl == NULL)
 {
  *--endcur = '\0';                    /* end string, overwrite trailing / */
  addresult(sofar);
  return;
 }

 if (!iswild(pl -> npart))
 {
  strcpy(endcur,pl -> npart);
  endcur += strlen(pl -> npart);
  *endcur = '\0';                      /* end current string */
/*  if (stat(sofar,&statbuf) == 0) */      /* if current piece exists */
  rc = GetFileInformation(&fileinfo, &timeinfo, sofar, strlen(sofar));
  if( rc >= 0 )  /* if current piece exists */
  {
      *endcur++ = '.';                  /* add slash to end */
      *endcur = '\0';                  /* and end the string */
      traverse(pl -> fwd,sofar,endcur);
  }
  return;
 }

/* segment contains wildcards, have to search directory */

 *endcur = '\0'; /* end current string */
 if( *(endcur-1) == '.' )
 {
   /* Stamp on trailing . */
   *--endcur = '\0';
   stamped = 1;
 }
 else
   stamped = 0;
/* if (stat(sofar,&statbuf) == -1) return;*/   /* doesn't exist, forget it */
/* if ((statbuf.st_mode & S_IFDIR) == 0) return;*/  /* not a directory, skip */

 if( sofar[0] != '\0' )
 {
  /* cwd is represented as a NULL string!! */
  rc = GetFileInformation(&fileinfo, &timeinfo, sofar, strlen(sofar));
  if( rc == -1 ) return;   /* doesn't exist, forget it */
  if( rc != 2 ) return;    /* not a directory, skip */
 }

 if ((fd = opendir(sofar)) == NULL) return;    /* can't open, forget it */

 if( stamped != 0 )
 {
   *endcur++ = '.';
   *endcur = '\0';
 }

 while ( (dirbuf = readdir(fd)) != NULL )
 {
  strncpy(nambuf,dirbuf->d_name,MAXNAMLEN); /* Get a null terminated copy!!! */
  nambuf[MAXNAMLEN] = '\0';
/*  if (dirbuf->d_ino != 0 && match(pl -> npart,nambuf)) {*/
  if ( match(pl -> npart,nambuf)) {
    char *eos;
    strcpy(endcur,nambuf);
    eos = endcur + strlen(nambuf);
    *eos = '.';                    /* end this segment */
    traverse(pl -> fwd,sofar,eos+1);
 }
}

 closedir(fd);
} 

/*
 * addresult:
 *  Adds a result string to the result array.  Increments the number
 *  of matches found, copies the found string into our string
 *  buffer, and puts a pointer to the buffer into the caller's result
 *  array.  Our free buffer pointer is updated.  If there is no
 *  more room in the caller's array, the number of matches is set to -1.
 * Input: a result string.
 * Returns: nothing.
 */

void
addresult(str)
char *str;
{
 int l;
 if (strncmp(str,"./",2) == 0) str += 2;
 if (--remlen < 0) {
  numfnd = -1;
  return;
 }
 l = strlen(str) + 1;                  /* size this will take up */
 if ((freeptr + l) > &sspace[SSPACE]) {
    numfnd = -1;                       /* do not record if not enough space */
    return;
  }
 strcpy(freeptr,str);
 *resptr++ = freeptr;
 freeptr += l;
 numfnd++;
}

int
iswild(str)
char *str;
{
 char c;
 while ((c = *str++) != '\0')
   if (c == '*' || c == '@') return(1);
 return(0);
}

/*
 * match:
 *  pattern matcher.  Takes a string and a pattern possibly containing
 *  the wildcard characters '*' and '@'.  Returns true if the pattern
 *  matches the string, false otherwise.
 * by: Jeff Damens, CUCCA
 *
 * Input: a string and a wildcard pattern.
 * Returns: 1 if match, 0 if no match.
 */


int
match(pattern,string) char *pattern,*string; {
    char *psave,*ssave; /* back up pointers for failure */
    psave = ssave = NULL;
    while (1) {
       for (; *pattern == *string; pattern++,string++)  /* skip first */
           if (*string == '\0') return(1);     /* end of strings, succeed */
       if (*string != '\0' && *pattern == '@') {
           pattern++;                  /* '@', let it match */
           string++;
       } else if (*pattern == '*') {   /* '*' ... */
           psave = ++pattern;          /* remember where we saw it */
           ssave = string;             /* let it match 0 chars */
       } else if (ssave != NULL && *ssave != '\0') {   /* if not at end  */
                                       /* ...have seen a star */
           string = ++ssave;           /* skip 1 char from string */
           pattern = psave;            /* and back up pattern */
       } else return(0);               /* otherwise just fail */
    }
}