hexview.c

#if HAVE_UNISTD_H
#   include <unistd.h>
#endif
#include "deco.h"
#include "scr.h"
#include "rec.h"

#define GETHEX(x)      ((x)>='A' ? ((x)&15)+9 : (x)&15)

extern viewfd;
extern viewraw;                         /* raw mode */
extern viewhlen;                        /* number of hex lines */
extern char viewsrch [SEARCHSZ];        /* search string */
extern char viewsbuf [SEARCHSZ];        /* search string buffer */
extern viewsbsz;                        /* search string size */
extern long viewseek;
extern REC *viewrec;

static void viewhhead (char *filename, int line);
static void viewhline (int line, int i);
static void viewhpage (int line);
static void prhline (char *p, int len);
static int hsearch (int l, int c, int *pline, int *pcol);
static int cvtsrch (char *from, char *to);

int hexview (char *filename)            /* hexadecimal viewer */
{
	register baseline;
	register char *p;
	int stepud = LINES-3;                   /* step up-down */
	int sline, soff;                        /* search position */
	int hexcursor;                          /* hex cursor mode */

	baseline = (viewseek+15)/16;
	hexcursor = 0;
	sline = soff = -1;
	VMPutString (LINES-1, 0, "\0011\16Help  \17 2\16      \17 3\16Raw   \17 4\16Hex   \17 5\16Top   \17 6\16Bottom\17 7\16Search\17 8\16      \17 9\16      \01710\16Quit \17\2");
	for (;;) {
		viewhpage (baseline);
		for (;;) {
			viewhhead (filename, baseline);
			if (sline>=baseline && sline<baseline+LINES-2)
				VMove (sline-baseline+1,
					hexcursor ? soff*3 : soff*2+48);
			else {
				hidecursor ();
				sline = -1;
			}
			VSync ();
			switch (KeyGet ()) {
			case meta ('A'):        /* f1 */
				runhelp ("hexview");
				continue;
			default:
				VBeep ();
				continue;
			case cntrl ('I'):       /* hex/text cursor */
				hexcursor ^= 1;
				continue;
			case cntrl (']'):       /* redraw screen */
				VRedraw ();
				continue;
			case meta ('C'):        /* f3 - raw */
				viewraw ^= 1;
				break;
			case meta ('D'):        /* f4 - hex */
				viewseek = baseline*16L;
				return (1);
			case cntrl ('C'):
			case cntrl ('['):
			case meta ('J'):        /* f0 - quit */
				return (0);
			case meta ('u'):        /* up */
				if (baseline <= 0)
					continue;
				--baseline;
				VDelLine (LINES-2);
				VInsLine (1);
				viewhline (baseline, 1);
				continue;
			case cntrl ('M'):       /* down */
			case cntrl ('J'):       /* down */
			case meta ('d'):        /* down */
				if (baseline >= viewhlen - (LINES-2))
					continue;
				VDelLine (1);
				VInsLine (LINES-2);
				viewhline (++baseline+LINES-3, LINES-2);
				continue;
			case meta ('n'):        /* next page */
				if (baseline >= viewhlen - (LINES-2))
					continue;
				baseline += stepud;
				if (baseline > viewhlen - (LINES-2))
					baseline = viewhlen - (LINES-2);
				break;
			case meta ('p'):        /* prev page */
				if (baseline <= 0)
					continue;
				baseline -= stepud;
				if (baseline < 0)
					baseline = 0;
				break;
			case meta ('E'):        /* top */
			case meta ('h'):        /* home */
				if (baseline == 0)
					continue;
				baseline = 0;
				break;
			case meta ('F'):        /* bottom */
			case meta ('e'):        /* end */
				if (baseline >= viewhlen - (LINES-2))
					continue;
				baseline = viewhlen - (LINES-2);
				break;
			case meta ('G'):        /* f7 - search */
				if (! (p = getstring (SEARCHSZ-1, viewsrch, " Search ", "Search for the string")))
					continue;
				strcpy (viewsrch, p);
				viewsbsz = cvtsrch (viewsrch, viewsbuf);
				if (sline < 0) {
					sline = baseline;
					soff = -1;
				}
				if (hsearch (sline, soff+1, &sline, &soff)) {
					if (baseline>sline || baseline+LINES-2<=sline)
						baseline = sline;
					if (baseline > viewhlen - (LINES-2))
						baseline = viewhlen - (LINES-2);
					if (baseline < 0)
						baseline = 0;
					break;
				}
				sline = -1;
				continue;
			}
			break;
		}
	}
}

static void viewhhead (char *filename, int line)
{
	register i;

	VSetDim ();
	VStandOut ();
	VMove (0, 0);
	for (i=80; --i>=0; VPutChar (' '));
	VMPutString (0, 1, "File ");
	VPutString (filename);
	VMove (0, 22);
	VPrint ("Lines %-5d Bytes %ld", viewrec->len, viewrec->size);
	VMove (0, 68);
	VPrint ("Byte %ld", line*16L);
	VSetNormal ();
	VStandEnd ();
}

static void viewhline (int line, int i)
{
	char buf [16], *p;
	int n;

	lseek (viewfd, line*16L, 0);
	n = read (viewfd, buf, sizeof (buf));
	p = buf;
	VMove (i, 0);                           /* move to line */
	if (n > 0)
		prhline (p, n);
	VClearLine ();                          /* clear it */
}

static void viewhpage (int line)
{
	char buf [1024], *p;
	register i;
	int n;

	lseek (viewfd, line*16L, 0);
	n = read (viewfd, buf, (unsigned) LINES*16);
	p = buf;
	for (i=1; i<LINES-1; ++i, n-=16, p+=16) {
		VMove (i, 0);                   /* move to line */
		if (n > 0)
			prhline (p, n);
		VClearLine ();          /* clear rest of line */
	}
}

static void prhline (char *p, int len)
{
	register i, c;

	if (len > 16)
		len = 16;
	for (i=0; i<16; ++i)
		if (i < len) {
			c = p [i];
			VPutChar ("0123456789abcdef" [c>>4&0xf]);
			VPutChar ("0123456789abcdef" [c&0xf]);
			VPutChar (' ');
		} else {
			VPutChar (' ');
			VPutChar (' ');
			VPutChar (' ');
		}
	for (i=0; i<len; ++i) {
		viewchar (*p++);
		if (i < len-1)
			VPutChar (' ');
	}
}

static int hsearch (int l, int c, int *pline, int *pcol)
{
	char buf [2*SEARCHSZ], *p;
	register char *s, *e;
	int n;

	for (;;) {
		lseek (viewfd, l*16L, 0);
		n = read (viewfd, buf, sizeof (buf));
		if (n <= 0)
			break;
		p = buf;
		e = buf + SEARCHSZ;
		for (s=p+c; s<e; ++s)
			if (! memcmp (s, viewsbuf, n<viewsbsz ? n : viewsbsz)) {
				*pline = l + (s - p) / 16;
				*pcol = (s - p) % 16;
				return (1);
			}
		if (n < sizeof (buf))
			break;
		l += SEARCHSZ / 16;
		c = 0;
	}
	error ("String not found");
	return (0);
}

static int cvtsrch (char *from, char *to)
{
	register c, x, count;

	count = 0;
	for (count=0; (c= *from++); *to++=c, ++count)
		if (c == '\\' && (x = *from)) {
			++from;
			if (x != '\\') {
				c = GETHEX (x);
				if ((x = *from) && x!='\\') {
					++from;
					c = c<<4 | GETHEX (x);
				}
			}
		}
	return (count);
}