/* ************************************************************

   implementation of 'cat' utility under MS-DOS

   Author:  David Lee Lambert

   - in my opinion,  this program is too short to bother with copyright...

   ************************************************************ */

#include <stdio.h>
#include <string.h>


#include <windows.h>

/* utility-routines taken from which.c */

struct svec {
    char **mem;
    int size;
    int cap;
};

int spush(struct svec * v, char * s)
{
    char **temp;

    if (! (v->size < v->cap)) {
       /* double the size if full */
       if (v->cap) 
	  v->cap *= 2;
       else v->cap = 1;
       temp = malloc(sizeof(char *) * v->cap);
       memcpy(temp, v->mem, v->size*sizeof(char *));
       free(v->mem);
       v->mem = temp;
    }

    v->mem[v->size++] = s;
    return 0;
}

int sfree(struct svec * v)
{
    int i;

    for (i = 0; i < v->size; i++)
        free(v->mem[i]);

    free(v->mem);
    return 0;
}

int sclear(struct svec * v)
{
    v->size = v->cap = 0;
    return 0;
}

/* unique code */

const char * help_text = "  Concatenate files\n"
"\n"
"syntax: cat [file [file [...]]] or\n"
"        cat [wilcard [file...]] etc.\n";

int main(int argc, char *argv[])
{
  struct svec filelist = {0, 0, 0};
  HANDLE hDir;
  int i;
  WIN32_FIND_DATA  filedata;
  HANDLE hInFile;
  char * pBuffer;
  DWORD bufsize, chunksize;

  pBuffer = malloc(bufsize = 4088);

  for (i = 1; i < argc; i++) {

    if (strcmpi(argv[i], "-h") == 0 ||
	strcmpi(argv[i], "/?") == 0) {
      printf("%s:\n%s", argv[0], help_text);
      goto end;
    }
    if (strcmpi(argv[i], "-") == 0) {
      spush(&filelist, strdup("-"));
      continue;
    }

    hDir = FindFirstFile(argv[i], &filedata);
    if (hDir != INVALID_HANDLE_VALUE) {
      spush(&filelist, strdup(filedata.cFileName));
      while (FindNextFile(argv[i], &filedata)) {
	spush(&filelist, strdup(filedata.cFileName));
      }
    } else {
      fprintf(stderr, "%s: File not found, error %ld\n",
	      argv[0], GetLastError());
    }
  }

  if (filelist.size == 0)
    spush(&filelist, strdup("-"));

  for (i = 0; i < filelist.size; i++) {

    if (strcmp(filelist.mem[i], "-") == 0) {
      do {
	chunksize = fread(pBuffer, 1, bufsize, stdin);
	fwrite(pBuffer, 1, chunksize, stdout);
      } while (chunksize == bufsize || !feof(stdin)); 
      continue;
    }

    hInFile = CreateFile(filelist.mem[i], 
			 GENERIC_READ,    /* access (read-write) mode */
			 FILE_SHARE_READ, /* share mode */
			 0,               /* address of security descriptor */
			 OPEN_EXISTING,   /* how to create */
			 FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN,
			                  /* file attributes */ 
			 0
			 );
    if (hInFile != INVALID_HANDLE_VALUE) {
      while(TRUE == ReadFile(hInFile, pBuffer, bufsize, &chunksize, 0) &&
	    chunksize != 0)
	fwrite(pBuffer, 1, chunksize, stdout);
      CloseHandle(hInFile);
    } else
      fprintf(stderr, "%s: could not open file '%s', error %ld\n",
	      argv[0], filelist.mem[i], GetLastError()); 
    
  }

 end:
  sfree(&filelist);
  free(pBuffer);

  return 0;
}