Il CD di internet/CD.iso/SOURCE/AP/JED/JED097-1.TAR/jed/src/vfile.c

C/C++ Source or Header | 1994-12-12 | 4.4 KB | 257 lines

/*
 *  Copyright (c) 1992, 1994 John E. Davis  ([e-mail])
 *  All Rights Reserved.
 */
#include <stdio.h>
#include <string.h>
#include <limits.h>


#ifdef VMS
#include <file.h>
#endif

#ifdef unix
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#ifdef SYSV
#include <sys/fcntl.h>
#endif
#endif

#ifdef msdos
#include <fcntl.h>
#include <io.h>
#include <sys/stat.h>
#endif

#ifdef __os2__
#include <fcntl.h>
#include <io.h>
#include <sys/types.h>
#include <sys/stat.h>
#endif

#ifndef O_RDONLY
#ifdef VMS
#include <file.h>
#else
#include <fcntl.h>
#endif
#endif

#include "config.h"
#include "slang.h"
#include "vfile.h"
#ifdef JED
#include "misc.h"
#endif


unsigned int VFile_Mode = VFILE_TEXT;

VFILE *vopen(char *file, unsigned int size, unsigned int fmode)
{
   int fd;
   unsigned int mode;

#ifdef O_BINARY
   mode = O_BINARY;
#else
   mode = 0;
#endif

   if ((fd = open(file, mode | O_RDONLY, 0)) < 0) return(NULL);
   return vstream(fd, size, fmode);
}

void vclose(VFILE *v)
{
   close(v->fd);
   if (v->buf != NULL) SLFREE(v->buf);
   SLFREE(v);
}


VFILE *vstream(int fd, unsigned int size, unsigned int mode)
{
   VFILE *v;

   if (NULL == (v = (VFILE *) SLMALLOC(sizeof(VFILE)))) return(NULL);
   v->bmax = v->bp = v->buf = NULL;
   v->fd = fd;
   v->eof = NULL;
   v->size = size;
   if (mode == 0) mode = VFile_Mode;
   v->mode = mode;
   v->cr_flag = 0;
   return v;
}

/* I malloc one extra so that I can always add a null character to last line */
char *vgets(VFILE *vp, unsigned int *num)
{
   register char *bp, *bp1;
   register char *bmax, *bpmax;
   char *neew;
   int fd = vp->fd;
   unsigned int n, max, fmode = vp->mode;
   int doread = 0;
   n = vp->size;

   *num = 0;
   if (NULL == vp->buf)
     {
#if defined (msdos) || defined (__os2_16__)
    if (!n) n = 512;
#else
    if (!n) n = 64 * 1024;
#endif

    if (NULL == (neew = (char *) SLMALLOC(n + 1)))
      {
#ifdef JED
         msg_error("Unable to malloc space.");
#endif
         return(NULL);
      }

    vp->bp = vp->buf = neew;
    vp->bmax = neew + n;
    doread = 1;
     }

   bp = vp->bp;
   if ((vp->eof != NULL) && (bp >= vp->eof)) return (NULL);
   bp1 = vp->buf;
   bmax = vp->bmax;

   while (1)
     {
    if (doread)
      {
         max = (int) (vp->bmax - bp);
         while ((n = read(fd, bp, max)) != 0)
           {
          max -= n;
          bp += n;
           }
         if (max) vp->eof = bp;
         if (bp == bp1)
           {
          return(NULL);
           }
         bp = bp1;
      }
    else bp1 = bp;

    /* extract a line */
    if (vp->eof != NULL) bmax = vp->eof;

    n = (unsigned int) (bmax - bp);
#if defined(msdos) && !defined(__WATCOMC__)
    if (n)
      {
         bpmax = bp;
         asm  {
        mov bx, di
        mov al, 10
        mov cx, n
        les di, bpmax
        cld
        repne scasb
        inc cx
        sub n, cx
        mov di, bx
         }
         bp += n;
         if (*bp != '\n') bp++;
      }

    if (bp < bmax)
      {
         vp->bp = ++bp;
         *num = (unsigned int) (bp - bp1);

         /* if it is text, replace the carriage return by a newline
            and adjust the number read by 1 */
         bp -= 2;
         if ((fmode == VFILE_TEXT) && (*num > 1) && (*bp == '\r'))
           {
          *bp = '\n';
          *num -= 1;
          vp->cr_flag = 1;
           }
         return bp1;
      }
#else
    if (NULL != (bpmax = MEMCHR(bp, '\n', n)))
      {
         bpmax++;
         vp->bp = bpmax;
         *num = (unsigned int) (bpmax - bp1);

         if ((fmode == VFILE_TEXT) && (*num > 1))
           {
          bpmax -= 2;
          if (*bpmax == '\r')
            {
               vp->cr_flag = 1;
               *bpmax = '\n'; (*num)--;
            }
           }
         return bp1;
      }
    bp = bp + n;
#endif    /* msdos */
    if (vp->eof != NULL)
      {
         *num = (unsigned int) (bp - bp1);
         vp->bp = bp;


#if defined(pc_system) || defined(__os2__)
         /* kill ^Z at EOF if present */
         if ((fmode == VFILE_TEXT) && (*num) && (26 == *(bp - 1)))
           {
          *num -= 1;
          if (!*num) bp1 = NULL;
           }
#endif
         return(bp1);
      }

    doread = 1;

    bp = bp1;
    bp1 = vp->buf;
    if (bp != bp1)
      {
         /* shift to beginning */
         while (bp < bmax) *bp1++ = *bp++;
         bp = bp1;
         bp1 = vp->buf;
      }
    else
      {
         bp = bmax;
         vp->bmax += 2 * (int) (vp->bmax - vp->buf);
         neew = (char *) SLREALLOC(vp->buf, vp->bmax - vp->buf + 1);
         if (neew == NULL)
           {
#ifdef JED
          msg_error("Realloc Error.");
#endif

          return(NULL);
           }

         bp = neew + (int) (bmax - vp->buf);
         bmax = vp->bmax = neew + (int) (vp->bmax - vp->buf);
         bp1 = vp->buf = neew;
      }
     }
}