hexedit: new applet
function old new delta hexedit_main - 930 +930 format_line - 197 +197 remap - 168 +168 move_mapping_further - 141 +141 move_mapping_lower - 107 +107 redraw_cur_line - 104 +104 packed_usage 31802 31812 +10 applet_names 2688 2696 +8 applet_main 1552 1556 +4 applet_suid 97 98 +1 applet_install_loc 194 195 +1 ------------------------------------------------------------------------------ (add/remove: 7/0 grow/shrink: 5/0 up/down: 1671/0) Total: 1671 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
357
miscutils/hexedit.c
Normal file
357
miscutils/hexedit.c
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@@ -0,0 +1,357 @@
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/*
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* Copyright (C) 2017 Denys Vlasenko <vda.linux@googlemail.com>
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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//config:config HEXEDIT
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//config: bool "hexedit"
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//config: default y
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//config: help
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//config: Edit file in hexadecimal.
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//applet:IF_HEXEDIT(APPLET(hexedit, BB_DIR_USR_BIN, BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_HEXEDIT) += hexedit.o
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#include "libbb.h"
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#define ESC "\033"
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#define HOME ESC"[H"
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#define CLEAR ESC"[H"ESC"[J"
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struct globals {
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smallint half;
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int fd;
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unsigned height;
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uint8_t *addr;
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uint8_t *current_byte;
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uint8_t *eof_byte;
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off_t size;
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off_t offset;
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struct termios orig_termios;
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};
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#define G (*ptr_to_globals)
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#define INIT_G() do { \
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SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
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} while (0)
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/* Hopefully there aren't arches with PAGE_SIZE > 64k */
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#define G_mapsize (64*1024)
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static void format_line(char *hex, uint8_t *data, off_t offset)
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{
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char *text = hex + 16*3;
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uint8_t *end, *end1;
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end1 = data + 15;
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if ((G.size - offset) > 0) {
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end = end1;
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if ((G.size - offset) <= 15)
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end = data + (G.size - offset) - 1;
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while (data <= end) {
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uint8_t c = *data++;
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*hex++ = bb_hexdigits_upcase[c >> 4];
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*hex++ = bb_hexdigits_upcase[c & 0xf];
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*hex++ = ' ';
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if (c < ' ' || c > 0x7e)
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c = '.';
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*text++ = c;
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}
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}
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while (data <= end1) {
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*hex++ = ' ';
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*hex++ = ' ';
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*hex++ = ' ';
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*text++ = ' ';
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data++;
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}
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*text = '\0';
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}
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static void redraw(void)
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{
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uint8_t *data;
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off_t offset;
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unsigned i;
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data = G.addr;
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offset = 0;
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i = 0;
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while (i < G.height) {
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char buf[16*4 + 8];
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format_line(buf, data, offset);
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printf(
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"\r\n%08"OFF_FMT"x %s" + (!i)*2, /* print \r\n only on 2nd line and later */
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offset, buf
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);
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data += 16;
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offset += 16;
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i++;
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}
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}
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static void redraw_cur_line(void)
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{
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off_t offset;
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int len;
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char buf[16*4 + 8];
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uint8_t *data;
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len = (0xf & (uintptr_t)G.current_byte);
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data = G.current_byte - len;
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offset = G.offset + (data - G.addr);
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format_line(buf, data, offset);
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printf(
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"\r%08"OFF_FMT"x %s",
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offset, buf
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);
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printf(
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"\r%08"OFF_FMT"x %.*s",
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offset, (len*3 + G.half), buf
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);
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}
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static void remap(unsigned cur_pos)
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{
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if (G.addr)
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munmap(G.addr, G_mapsize);
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G.addr = mmap(NULL,
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G_mapsize,
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PROT_READ | PROT_WRITE,
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MAP_SHARED,
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G.fd,
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G.offset
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);
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if (G.addr == MAP_FAILED)
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//TODO: restore termios?
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bb_perror_msg_and_die("mmap");
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G.current_byte = G.addr + cur_pos;
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G.eof_byte = G.addr + G_mapsize;
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if ((G.size - G.offset) < G_mapsize) {
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/* mapping covers tail of the file */
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/* we do have a mapped byte which is past eof */
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G.eof_byte = G.addr + (G.size - G.offset);
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}
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}
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static void move_mapping_further(void)
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{
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unsigned pos;
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unsigned pagesize;
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if ((G.size - G.offset) < G_mapsize)
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return; /* can't move mapping even further, it's at the end already */
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pagesize = getpagesize(); /* constant on most arches */
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pos = G.current_byte - G.addr;
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if (pos >= pagesize) {
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/* Move offset up until current position is in 1st page */
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do {
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G.offset += pagesize;
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if (G.offset == 0) { /* whoops */
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G.offset -= pagesize;
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break;
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}
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pos -= pagesize;
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} while (pos >= pagesize);
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remap(pos);
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}
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}
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static void move_mapping_lower(void)
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{
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unsigned pos;
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unsigned pagesize;
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if (G.offset == 0)
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return; /* we are at 0 already */
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pagesize = getpagesize(); /* constant on most arches */
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pos = G.current_byte - G.addr;
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/* Move offset down until current position is in last page */
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pos += pagesize;
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while (pos < G_mapsize) {
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pos += pagesize;
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G.offset -= pagesize;
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if (G.offset == 0)
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break;
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}
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pos -= pagesize;
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remap(pos);
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}
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static void sig_catcher(int sig)
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{
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tcsetattr_stdin_TCSANOW(&G.orig_termios);
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kill_myself_with_sig(sig);
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}
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//usage:#define hexedit_trivial_usage
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//usage: "FILE"
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//usage:#define hexedit_full_usage "\n\n"
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//usage: "Edit FILE in hexadecimal"
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int hexedit_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int hexedit_main(int argc UNUSED_PARAM, char **argv)
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{
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unsigned row = 0;
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INIT_G();
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getopt32(argv, "");
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argv += optind;
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get_terminal_width_height(-1, NULL, &G.height);
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G.fd = xopen(*argv, O_RDWR);
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G.size = xlseek(G.fd, 0, SEEK_END);
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/* TERMIOS_RAW_CRNL suppresses \n -> \r\n translation, helps with down-arrow */
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set_termios_to_raw(STDIN_FILENO, &G.orig_termios, TERMIOS_RAW_CRNL);
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bb_signals(BB_FATAL_SIGS, sig_catcher);
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remap(0);
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printf(CLEAR);
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redraw();
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printf(HOME "%08x ", 0);
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//TODO: //PgUp/PgDown; Home/End: start/end of line; '<'/'>': start/end of file
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//Backspace: undo
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//Enter: goto specified position
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//Ctrl-L: redraw
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//Ctrl-X: save and exit (maybe also Q?)
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//Ctrl-Z: suspend
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//'/', Ctrl-S: search
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//TODO: go to end-of-screen on exit (for this, sighandler should interrupt read_key())
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//TODO: detect window resize
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//TODO: read-only mode if open(O_RDWR) fails? hide cursor in this case?
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//TODO: smarter redraw: if down-arrow is pressed on last visible line,
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//emit LF, then print the tail of next line, then CR, then beginning -
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//which makes cursor end up exactly where it should be! Same for up-arrow.
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for (;;) {
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char read_key_buffer[KEYCODE_BUFFER_SIZE];
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int32_t key;
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uint8_t byte;
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fflush_all();
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key = read_key(STDIN_FILENO, read_key_buffer, -1);
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switch (key) {
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case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
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case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
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/* lowercase, then convert to '0'+10...15 */
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key = (key | 0x20) - ('a' - '0' - 10);
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/* fall through */
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case '0': case '1': case '2': case '3': case '4':
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case '5': case '6': case '7': case '8': case '9':
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if (G.current_byte == G.eof_byte) {
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move_mapping_further();
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if (G.current_byte == G.eof_byte) {
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/* extend the file */
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if (++G.size <= 0 /* overflow? */
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|| ftruncate(G.fd, G.size) != 0 /* error extending? (e.g. block dev) */
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) {
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G.size--;
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break;
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}
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G.eof_byte++;
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}
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}
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key -= '0';
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byte = *G.current_byte & 0xf0;
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if (!G.half) {
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byte = *G.current_byte & 0x0f;
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key <<= 4;
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}
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*G.current_byte = byte + key;
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/* can't just print one updated hex char: need to update right-hand ASCII too */
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redraw_cur_line();
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/* fall through */
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case KEYCODE_RIGHT:
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if (G.current_byte == G.eof_byte)
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break; /* eof - don't allow going past it */
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byte = *G.current_byte;
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if (!G.half) {
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G.half = 1;
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putchar(bb_hexdigits_upcase[byte >> 4]);
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} else {
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G.half = 0;
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G.current_byte++;
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if ((0xf & (uintptr_t)G.current_byte) == 0) {
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/* rightmost pos, wrap to next line */
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if (G.current_byte == G.eof_byte)
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move_mapping_further();
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printf(ESC"[46D"); /* cursor left 3*15 + 1 chars */
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goto down;
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}
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putchar(bb_hexdigits_upcase[byte & 0xf]);
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putchar(' ');
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}
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break;
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case KEYCODE_DOWN:
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G.current_byte += 16;
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if (G.current_byte >= G.eof_byte) {
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move_mapping_further();
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if (G.current_byte > G.eof_byte) {
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/* eof - don't allow going past it */
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G.current_byte -= 16;
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break;
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}
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}
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down:
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putchar('\n'); /* down one line, possibly scroll screen */
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row++;
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if (row >= G.height) {
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row--;
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redraw_cur_line();
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}
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break;
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case KEYCODE_LEFT:
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if (G.half) {
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G.half = 0;
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printf(ESC"[D");
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break;
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}
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if ((0xf & (uintptr_t)G.current_byte) == 0) {
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/* leftmost pos, wrap to prev line */
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if (G.current_byte == G.addr)
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move_mapping_lower();
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if ((G.current_byte - G.addr) < 16)
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break; /* first line, don't do anything */
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G.half = 1;
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G.current_byte--;
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printf(ESC"[46C"); /* cursor right 3*15 + 1 chars */
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goto up;
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}
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G.half = 1;
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G.current_byte--;
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printf(ESC"[2D");
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break;
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case KEYCODE_UP:
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if ((G.current_byte - G.addr) < 16) {
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move_mapping_lower();
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if ((G.current_byte - G.addr) < 16)
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break;
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}
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G.current_byte -= 16;
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up:
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if (row != 0) {
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row--;
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printf(ESC"[A"); /* up (won't scroll) */
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} else {
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//printf(ESC"[T"); /* scroll up */ - not implemented on Linux VT!
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printf(ESC"M"); /* scroll up */
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redraw_cur_line();
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}
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break;
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}
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}
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return EXIT_SUCCESS;
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}
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