aboutsummaryrefslogtreecommitdiff
path: root/toys/other/hexedit.c
blob: 668e51c47008842e4a42376cb433c2ed6f79ab25 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/* hexedit.c - Hexadecimal file editor
 *
 * Copyright 2015 Rob Landley <rob@landley.net>
 *
 * No standard

USE_HEXEDIT(NEWTOY(hexedit, "<1>1r", TOYFLAG_USR|TOYFLAG_BIN))

config HEXEDIT
  bool "hexedit"
  default n
  help
    usage: hexedit FILENAME

    Hexadecimal file editor.

    -r	Read only (display but don't edit)
*/

#define FOR_hexedit
#include "toys.h"

GLOBALS(
  char *data;
  long long len, base;
  int numlen;
  unsigned height;
)

static void esc(char *s)
{
  printf("\033[%s", s);
}

static void jump(int x, int y)
{
  char s[32];

  sprintf(s, "%d;%dH", y+1, x+1);
  esc(s);
}

static void fix_terminal(void)
{
  set_terminal(1, 0, 0);
  esc("?25h");
  esc("0m");
  jump(0, 999);
}

static void sigttyreset(int i)
{
  fix_terminal();
  // how do I re-raise the signal so it dies with right signal info for wait()?
  _exit(127);
}

// Render all characters printable, using color to distinguish.
static void draw_char(char broiled)
{
  if (broiled<32 || broiled>=127) {
    if (broiled>127) {
      esc("2m");
      broiled &= 127;
    }
    if (broiled<32 || broiled==127) {
      esc("7m");
      if (broiled==127) broiled = 32;
      else broiled += 64;
    }
    printf("%c", broiled);
    esc("0m");
  } else printf("%c", broiled);
}

static void draw_line(long long yy)
{
  int x;

  yy = (TT.base+yy)*16;

  if (yy<TT.len) {
    printf("\r%0*llX ", TT.numlen, yy);
    for (x=0; x<16; x++) {
      if (yy+x<TT.len) printf(" %02X", TT.data[yy+x]);
      else printf("   ");
    }
    printf("  ");
    for (x=0; x<16; x++) draw_char(TT.data[yy+x]);
  }
  esc("K");
}

static void draw_page(void)
{
  int y;

  jump(0, 0);
  for (y = 0; y<TT.height; y++) {
    if (y) printf("\r\n");
    draw_line(y);
  }
}

// side: 0 = editing left, 1 = editing right, 2 = clear, 3 = read only
static void highlight(int xx, int yy, int side)
{
  char cc = TT.data[16*(TT.base+yy)+xx];
  int i;

  // Display cursor
  jump(2+TT.numlen+3*xx, yy);
  esc("0m");
  if (side!=2) esc("7m");
  if (side>1) printf("%02X", cc);
  else for (i=0; i<2;) {
    if (side==i) esc("32m");
    printf("%X", (cc>>(4*(1&++i)))&15);
  }
  esc("0m");
  jump(TT.numlen+17*3+xx, yy);
  draw_char(cc);
}

#define KEY_UP 256
#define KEY_DOWN 257
#define KEY_RIGHT 258
#define KEY_LEFT 259
#define KEY_PGUP 260
#define KEY_PGDN 261
#define KEY_HOME 262
#define KEY_END  263
#define KEY_INSERT 264

void hexedit_main(void)
{
  // up down right left pgup pgdn home end ins
  char *keys[] = {"\033[A", "\033[B", "\033[C", "\033[D", "\033[5~", "\033[6~",
                  "\033OH", "\033OF", "\033[2~", 0};
  long long pos;
  int x, y, i, side = 0, key, ro = toys.optflags&FLAG_r,
      fd = xopen(*toys.optargs, ro ? O_RDONLY : O_RDWR);

  TT.height = 25;
  terminal_size(0, &TT.height);
  if (TT.height) TT.height--;
  sigatexit(sigttyreset);
  esc("0m");
  esc("?25l");
  fflush(0);
  set_terminal(1, 1, 0);

  if ((TT.len = fdlength(fd))<0) error_exit("bad length");
  if (sizeof(long)==32 && TT.len>SIZE_MAX) TT.len = SIZE_MAX;
  // count file length hex digits, rounded up to multiple of 4
  for (pos = TT.len, TT.numlen = 0; pos; pos >>= 4, TT.numlen++);
  TT.numlen += (4-TT.numlen)&3;

  TT.data = mmap(0, TT.len, PROT_READ|(PROT_WRITE*!ro), MAP_SHARED, fd, 0);

  draw_page();

  y = x = 0;
  for (;;) {
    // Get position within file, trimming if we overshot end.
    pos = 16*(TT.base+y)+x;
    if (pos>=TT.len) {
      pos = TT.len-1;
      x = (TT.len-1)%15;
    }

    // Display cursor
    highlight(x, y, ro ? 3 : side);
    fflush(0);

    // Wait for next key
    key = scan_key(toybuf, keys, 1);
    // Exit for q, ctrl-c, ctrl-d, escape, or EOF
    if (key==-1 || key==3 || key==4 || key==27 || key=='q') break;
    highlight(x, y, 2);

    if (key>='a' && key<='f') key-=32;
    if (!ro && ((key>='0' && key<='9') || (key>='A' && key<='F'))) {
      i = key - '0';
      if (i>9) i -= 7;
      TT.data[pos] &= 15<<(4*side);
      TT.data[pos] |= i<<(4*!side);

      highlight(x, y, ++side);
      if (side==2) {
        side = 0;
        if (++pos<TT.len && ++x==16) {
          x = 0;
          if (++y == TT.height) {
            --y;
            goto down;
          }
        }
      }
    }
    if (key>255) side = 0;
    if (key==KEY_UP) {
      if (--y<0) {
        if (TT.base) {
          TT.base--;
          esc("1T");
          jump(0, TT.height);
          esc("K");
          jump(0, 0);
          draw_line(0);
        }
        y = 0;
      }
    } else if (key==KEY_DOWN) {
      if (y == TT.height-1 && pos+32<TT.len) {
down:
        TT.base++;
        esc("1S");
        jump(0, TT.height-1);
        draw_line(TT.height-1);
      }
      if (pos+16<TT.len && ++y>=TT.height) y--;
    } else if (key==KEY_RIGHT) {
      if (x<15 && pos+1<TT.len) x++;
    } else if (key==KEY_LEFT) {
      if (x) x--;
    } else if (key==KEY_PGUP) {
      TT.base -= TT.height;
      if (TT.base<0) TT.base = 0;
      draw_page();
    } else if (key==KEY_PGDN) {
      TT.base += TT.height;
      if ((TT.base*16)>=TT.len) TT.base=(TT.len-1)/16;
      while ((TT.base+y)*16>=TT.len) y--;
      if (16*(TT.base+y)+x>=TT.len) x = (TT.len-1)&15;
      draw_page();
    } else if (key==KEY_HOME) {
      TT.base = 0;
      x = 0;
      draw_page();
    } else if (key==KEY_END) {
      TT.base=(TT.len-1)/16;
      x = (TT.len-1)&15;
      draw_page();
    }
  }
  munmap(TT.data, TT.len);
  close(fd);
  fix_terminal();
}