//----------------------------------------------------------------
// liveview.cpp (An enhancement of our 'fileview.cpp')
//
// This program displays the contents of a specified file
// in hexadecimal and ascii formats (including any device
// special files representing storage media). A user may
// navigate the file's contents using arrow-key commands,
// or may adjust the format of the hexadecimal display to
// select from among five data-sizes: byte (B), word (W),
// doubleword (D), quadword (Q) or octaword (O). It also
// is possible to seek to a specified position within the
// file by hitting the <ENTER>-key and then typing in the
// desired (hexadecimal) address. Type <ESCAPE> to quit.
//
// compile-and-link using: $ make liveview
//
// programmer: ALLAN CRUSE
// written on: 26 OCT 2002
// revised on: 07 JUN 2006 -- removed reliance on 'ncurses'
// revised on: 07 JUN 2007 -- view gets continually updated
// revised on: 29 OCT 2007 -- to hide cursor during redraws
//----------------------------------------------------------------
#include <stdio.h> // for printf(), perror(), fflush()
#include <fcntl.h> // for open()
#include <string.h> // for strncpy()
#include <unistd.h> // for read(), lseek64()
#include <stdlib.h> // for exit()
#include <termios.h> // for tcgetattr(), tcsetattr()
#define MAXNAME 80
#define BUFHIGH 16
#define BUFWIDE 16
#define BUFSIZE 256
#define ROW 6
#define COL 2
#define KB_SEEK 0x0000000A
#define KB_QUIT 0x0000001B
#define KB_BACK 0x0000007F
#define KB_HOME 0x00315B1B
#define KB_LNUP 0x00415B1B
#define KB_PGUP 0x00355B1B
#define KB_LEFT 0x00445B1B
#define KB_RGHT 0x00435B1B
#define KB_LNDN 0x00425B1B
#define KB_PGDN 0x00365B1B
#define KB_END 0x00345B1B
#define KB_DEL 0x00335B1B
char progname[] = "LIVEVIEW";
char filename[ MAXNAME + 1 ];
char buffer[ BUFSIZE ];
char outline[ 80 ];
int main( int argc, char *argv[] )
{
// setup the filename (if supplied), else terminate
if ( argc > 1 ) strncpy( filename, argv[1], MAXNAME );
else { fprintf( stderr, "argument needed\n" ); exit(1); }
// open the file for reading
int fd = open( filename, O_RDONLY );
if ( fd < 0 ) { perror( filename ); exit(1); }
// obtain the filesize (if possible)
long long filesize = lseek64( fd, 0LL, SEEK_END );
if ( filesize < 0LL )
{
fprintf( stderr, "cannot locate \'end-of-file\' \n" );
exit(1);
}
long long incmin = ( 1LL << 8 );
long long incmax = ( 1LL << 36 );
long long posmin = 0LL;
long long posmax = (filesize - 241LL)&~0xF;
if ( posmax < posmin ) posmax = posmin;
// initiate noncanonical terminal input
struct termios tty_orig;
tcgetattr( STDIN_FILENO, &tty_orig );
struct termios tty_work = tty_orig;
tty_work.c_lflag &= ~( ECHO | ICANON ); // | ISIG );
///tty_work.c_cc[ VMIN ] = 1;
tty_work.c_cc[ VMIN ] = 0; // <--- for 'live' view
tty_work.c_cc[ VTIME ] = 0;
tcsetattr( STDIN_FILENO, TCSAFLUSH, &tty_work );
printf( "\e[H\e[J" );
// display the legend
int i, j, k;
k = (77 - strlen( progname ))/2;
printf( "\e[%d;%dH %s ", 1, k, progname );
k = (77 - strlen( filename ))/2;
printf( "\e[%d;%dH\'%s\'", 3, k, filename );
char infomsg[ 80 ];
sprintf( infomsg, "filesize: %llu (=0x%013llX)", filesize, filesize );
k = (78 - strlen( infomsg ));
printf( "\e[%d;%dH%s", 24, k, infomsg );
fflush( stdout );
// main loop to navigate the file
long long pageincr = incmin;
long long lineincr = 16LL;
long long position = 0LL;
long long location = 0LL;
int format = 1;
int done = 0;
while ( !done )
{
// erase prior buffer contents
for (j = 0; j < BUFSIZE; j++) buffer[ j ] = ~0;
// restore 'pageincr' to prescribed bounds
if ( pageincr == 0LL ) pageincr = incmax;
else if ( pageincr < incmin ) pageincr = incmin;
else if ( pageincr > incmax ) pageincr = incmax;
// get current location of file-pointer position
location = lseek64( fd, position, SEEK_SET );
// try to fill 'buffer[]' with data from the file
char *where = buffer;
int to_read = BUFSIZE;
while ( to_read > 0 )
{
int nbytes = read( fd, where, to_read );
if ( nbytes <= 0 ) break;
to_read -= nbytes;
where += nbytes;
}
int datalen = BUFSIZE - to_read;
// display the data just read into the 'buffer[]' array
unsigned char *bp;
unsigned short *wp;
unsigned int *dp;
unsigned long long *qp;
printf( "\e[?25l" ); // hide the cursor
for (i = 0; i < BUFHIGH; i++)
{
int linelen;
// draw the line-location (13-digit hexadecimal)
linelen = sprintf( outline, "%013llX ", location );
// draw the line in the selected hexadecimal format
switch ( format )
{
case 1: // 'byte' format
bp = (unsigned char*)&buffer[ i*BUFWIDE ];
for (j = 0; j < BUFWIDE; j++)
linelen += sprintf( outline+linelen,
"%02X ", bp[j] );
break;
case 2: // 'word' format
wp = (unsigned short*)&buffer[ i*BUFWIDE ];
for (j = 0; j < BUFWIDE/2; j++)
linelen += sprintf( outline+linelen,
" %04X ", wp[j] );
break;
case 4: // 'dword' format
dp = (unsigned int*)&buffer[ i*BUFWIDE ];
for (j = 0; j < BUFWIDE/4; j++)
linelen += sprintf( outline+linelen,
" %08X ", dp[j] );
break;
case 8: // 'qword' format
qp = (unsigned long long*)&buffer[ i*BUFWIDE ];
for (j = 0; j < BUFWIDE/8; j++)
linelen += sprintf( outline+linelen,
" %016llX ", qp[j] );
break;
case 16: // 'octaword'
qp = (unsigned long long*)&buffer[ i*BUFWIDE ];
linelen += sprintf( outline+linelen, " " );
linelen += sprintf( outline+linelen,
" %016llX%016llX ", qp[1], qp[0] );
linelen += sprintf( outline+linelen, " " );
break;
}
// draw the line in ascii format
for (j = 0; j < BUFWIDE; j++)
{
char ch = buffer[ i*BUFWIDE + j ];
if (( ch < 0x20 )||( ch > 0x7E )) ch = '.';
linelen += sprintf( outline+linelen, "%c", ch);
}
// transfer this output-line to the screen
printf( "\e[%d;%dH%s", ROW+i, COL, outline );
// advance 'location' for the next output-line
location += BUFWIDE;
}
printf( "\e[?25h" ); // show the cursor again
printf( "\e[%d;%dH", 23, COL );
fflush( stdout );
// check for a new keypress
long long inch = 0LL;
if ( read( STDIN_FILENO, &inch, sizeof( inch ) ) > 0 )
printf( "\e[%d;%dH%60s", 23, COL, " " );
else continue;
// interpret navigation or formatting command
inch &= 0x00FFFFFFLL;
switch ( inch )
{
// move to the file's beginning/ending
case 'H': case 'h':
case KB_HOME: position = posmin; break;
case 'E': case 'e':
case KB_END: position = posmax; break;
// move forward/backward by one line
case KB_LNDN: position += BUFWIDE; break;
case KB_LNUP: position -= BUFWIDE; break;
// move forward/packward by one page
case KB_PGDN: position += pageincr; break;
case KB_PGUP: position -= pageincr; break;
// increase/decrease the page-size increment
case KB_RGHT: pageincr >>= 4; break;
case KB_LEFT: pageincr <<= 4; break;
// reset the hexadecimal output-format
case 'B': case 'b': format = 1; break;
case 'W': case 'w': format = 2; break;
case 'D': case 'd': format = 4; break;
case 'Q': case 'q': format = 8; break;
case 'O': case 'o': format = 16; break;
// seek to a user-specified file-position
case KB_SEEK:
printf( "\e[%d;%dHAddress: ", 23, COL );
fflush( stdout );
{
char inbuf[ 16 ] = {0};
//tcsetattr( STDIN_FILENO, TCSANOW, &tty_orig );
int i = 0;
while ( i < 15 )
{
long long ch = 0;
read( STDIN_FILENO, &ch, sizeof( ch ) );
ch &= 0xFFFFFF;
if ( ch == '\n' ) break;
if ( ch == KB_QUIT ) { inbuf[0] = 0; break; }
if ( ch == KB_LEFT ) ch = KB_BACK;
if ( ch == KB_DEL ) ch = KB_BACK;
if (( ch == KB_BACK )&&( i > 0 ))
{
inbuf[--i] = 0;
printf( "\b \b" );
fflush( stdout );
}
if (( ch < 0x20 )||( ch > 0x7E )) continue;
inbuf[ i++ ] = ch;
printf( "%c", ch );
fflush( stdout );
}
printf( "\e[%d;%dH%70s", 23, COL, " " );
fflush( stdout );
position = strtoull( inbuf, NULL, 16 );
position &= ~0xFLL; // paragraph align
}
break;
// program termination
case KB_QUIT: done = 1; break;
default:
printf( "\e[%d;%dHHit <ESC> to quit", 23, 2 );
}
fflush( stdout );
// insure that 'position' remains within bounds
if ( position < posmin ) position = posmin;
if ( position > posmax ) position = posmax;
}
// restore canonical terminal behavior
tcsetattr( STDIN_FILENO, TCSAFLUSH, &tty_orig );
printf( "\e[%d;%dH\e[0J\n", 23, 0 );
}