file.c

   1 /* hexedit -- Hexadecimal Editor for Binary Files
   2    Copyright (C) 1998 Pixel (Pascal Rigaux)
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.*/
  17 #include "hexedit.h"
  18
  19 void openFile(void)
  20 {
  21   struct stat st;
  22
  23   if (!is_file(fileName)) {
  24     fprintf(stderr, "%s: %s: Not a file.\n", progName, fileName);
  25     exit(1);
  26   }
  27
  28   /* edited should be cleaned here (assert(edited == NULL)) */
  29   if ((fd = open(fileName, O_RDWR)) == -1) {
  30     isReadOnly = TRUE;
  31     if ((fd = open(fileName, O_RDONLY)) == -1) {
  32       if (page) exitCurses();
  33       if (fileName[0] == '-') DIE(usage);
  34       fprintf(stderr, "%s: ", progName);
  35       perror(fileName);
  36       exit(1);
  37     }
  38   } else isReadOnly = FALSE;
  39   baseName = basename(fileName);
  40   mark_set = FALSE;
  41   lastEditedLoc = base = cursor = cursorOffset = 0;
  42
  43   /* check file size- doesn't work on devices.  I considered implementing a conquer-and-divide algorithm, but it would unpleasant on tape drives and such. */
  44   if (fstat(fd, &st) != -1 && st.st_size > 0)
  45     fileSize = st.st_size;
  46   else {
  47 #ifdef BLKGETSIZE
  48     unsigned long i;
  49     if (ioctl(fd, BLKGETSIZE, &i) == 0)
  50       fileSize = (INT) i * 512;
  51     else
  52 #endif
  53       fileSize = 0;
  54   }
  55   biggestLoc = fileSize;
  56 }
  57
  58 void readFile(void)
  59 {
  60   typePage *p;
  61   INT i;
  62
  63   memset(buffer, 0, page * sizeof(*buffer));
  64
  65   LSEEK(fd, base);
  66   nbBytes = read(fd, buffer, page);
  67   if (nbBytes < 0)
  68     nbBytes = 0;
  69   else if (nbBytes && base + nbBytes > biggestLoc)
  70     biggestLoc = base + nbBytes;
  71   memset(bufferAttr, A_NORMAL, page * sizeof(*bufferAttr));
  72   for (p = edited; p; p = p->next) {
  73     for (i = MAX(base, p->base); i < MIN(p->base + p->size, base + page); i++) {
  74       if (buffer[i - base] != p->vals[i - p->base]) {
  75         buffer[i - base] = p->vals[i - p->base];
  76         bufferAttr[i - base] |= MODIFIED;
  77       }
  78     }
  79     if (p->base + p->size > base + nbBytes) {   /* Check for modifications past EOF */
  80       for(; p->base + p->size > base + nbBytes && nbBytes < page; nbBytes++)
  81         bufferAttr[nbBytes] |= MODIFIED;
  82     }
  83   }
  84   if (mark_set) markSelectedRegion();
  85
  86 }
  87
  88 int findFile(void)
  89 {
  90   char *p, tmp[BLOCK_SEARCH_SIZE];
  91   p = lastFindFile ? strdup(lastFindFile) : NULL;
  92   if (!displayMessageAndGetString("File name: ", &p, tmp, sizeof(tmp))) return FALSE;
  93   if (!is_file(tmp)) return FALSE;
  94   FREE(lastFindFile); lastFindFile = fileName;
  95   fileName = p;
  96   return TRUE;
  97 }
  98
  99
 100 INT getfilesize(void)
 101 {
 102   return MAX(lastEditedLoc, biggestLoc);
 103 }
 104
 105
 106 /* tryloc:
 107  *   returns TRUE if loc is an apropriate location to place the cursor
 108  *   assumes the file won't shrink.
 109  *   returns TRUE if the cursor is one past EOF to allow appending
 110  */
 111
 112 int tryloc(INT loc)
 113 {
 114   char c;
 115   if (loc < 0)
 116     return FALSE;
 117   if (loc <= lastEditedLoc)
 118     return TRUE;
 119
 120   if (loc <= biggestLoc)
 121     return TRUE;
 122
 123   if (LSEEK_(fd, loc - 1) != -1 && /* don't have to worry about loc - 1 < 0 */
 124       read(fd, &c, 1) == 1) {
 125     biggestLoc = loc;
 126     return TRUE;
 127   }
 128   return FALSE;
 129 }
 130
 131 int is_file(char *name)
 132 {
 133   struct stat st;
 134   return stat(name, &st) != -1 && !S_ISDIR(st.st_mode);
 135 }
 136
 137