20060303a

1 files changed, 335 insertions, 0 deletions

diff --git a/appl/cmd/mdb.b b/appl/cmd/mdb.b
new file mode 100644
index 00000000..71938af5
--- /dev/null
+++ b/appl/cmd/mdb.b
@@ -0,0 +1,335 @@
+implement Mdb;
+
+include "sys.m";
+	sys: Sys;
+	stderr: ref Sys->FD;
+	print, sprint: import sys;
+
+include "draw.m";
+include "string.m";
+	str: String;
+include "bufio.m";
+	bufio: Bufio;
+	Iobuf: import bufio;
+
+Mdb: module
+{
+	init: fn(nil: ref Draw->Context, argv: list of string);
+};
+
+mfd: ref Sys->FD;
+dot := 0;
+lastaddr := 0;
+count := 1;
+
+atoi(s: string): int
+{
+        b := 10;
+        if(s == nil)
+                return 0;
+        if(s[0] == '0') {
+                b = 8;
+                s = s[1:];
+                if(s == nil)
+                        return 0;
+                if(s[0] == 'x' || s[0] == 'X') {
+                        b = 16;
+                        s = s[1:];
+                }
+        }
+        n: int;
+        (n, nil) = str->toint(s, b);
+        return n;
+}
+
+eatws(s: string): string
+{
+	for (i := 0; i < len s; i++)
+		if (s[i] != ' ' && s[i] != '\t')
+			return s[i:];
+	return nil;
+}
+
+eatnum(s: string): string
+{
+	if(len s == 0)
+		return s;
+	while(gotnum(s) || gotalpha(s))
+		s = s[1:];
+	return s;
+}
+
+gotnum(s: string): int
+{
+	if(len s == 0)
+		return 0;
+	if(s[0] >= '0' && s[0] <= '9')
+		return 1;
+	else
+		return 0;
+}
+
+gotalpha(s: string): int
+{
+	if(len s == 0)
+		return 0;
+	if((s[0] >= 'a' && s[0] <= 'z') || (s[0] >= 'A' && s[0] <= 'Z'))
+		return 1;
+	else
+		return 0;
+}
+
+getexpr(s: string): (string, int, int)
+{
+	ov: int;
+	v := 0;
+	op := '+';
+	for(;;) {
+		ov = v;
+		s = eatws(s);
+		if(s == nil)
+			return (nil, 0, 0);
+		if(s[0] == '.' || s[0] == '+' || s[0] == '^') {
+			v = dot;
+			s = s[1:];
+		} else if(s[0] == '"') {
+			v = lastaddr;
+			s = s[1:];
+		} else if(s[0] == '(') {
+			(s, v, nil) = getexpr(s[1:]);
+			s = s[1:];
+		} else if(gotnum(s)) {
+			v = atoi(s);
+			s = eatnum(s);
+		} else
+			return (s, 0, 0);
+		case op {
+		'+' => v = ov+v;
+		'-' => v = ov-v;
+		'*' => v = ov*v;
+		'%' => v = ov/v;
+		'&' => v = ov&v;
+		'|' => v = ov|v;
+		}
+		if(s == nil)
+			return (nil, v, 1);
+		case s[0] {
+		'+' or '-' or '*' or '%' or '&' or '|' =>
+			op = s[0]; s = s[1:];
+		* =>
+			return (eatws(s), v, 1);
+		}
+	}
+}
+
+lastcmd := "";
+
+docmd(s: string)
+{
+	ok: int;
+	n: int;
+	s = eatws(s);
+	(s, n, ok) = getexpr(s);
+	if(ok) {
+		dot = n; 
+		lastaddr = n;
+	}
+	count = 1;
+	if(s != nil && s[0] == ',') {
+		(s, n, ok) = getexpr(s[1:]);
+		if(ok)
+			count = n;
+	}
+	if(s == nil && (s = lastcmd) == nil) 
+		return;
+	lastcmd = s;
+	cmd := s[0];
+	case cmd {
+	'?' or '/' =>
+		case s[1] {
+		'w' =>
+			writemem(2, s[2:]);
+		'W' =>
+			writemem(4, s[2:]);
+		* =>
+			dumpmem(s[1:], cmd);
+		}
+	'=' =>
+		dumpmem(s[1:], cmd);
+	* =>
+		sys->fprint(stderr, "invalid cmd: %c\n", cmd);
+	}
+}
+
+octal(n: int, d: int): string
+{
+	s: string;
+	do {
+		s = string (n%8) + s;
+		n /= 8;
+	} while(d-- > 1);
+	return "0" + s;
+}
+
+printable(c: int): string
+{
+	case c {
+	32 to 126 =>
+		return sprint("%c", c);
+	'\n' =>
+		return "\\n";
+	'\r' =>
+		return "\\r";
+	'\b' =>
+		return "\\b";
+	'\a' =>
+		return "\\a";
+	'\v' =>
+		return "\\v";
+	* =>
+		return sprint("\\x%2.2x", c);
+	}
+		
+}
+
+dumpmem(s: string, t: int)
+{
+	n := 0;
+	c := count;
+	while(c-- > 0) for(p:=0; p<len s; p++) {
+		fmt := s[p];
+		case fmt {
+		'b' or 'c' or 'C' =>
+			n = 1;
+		'x' or 'd' or 'u' or 'o' =>
+			n = 2; 
+		'X' or 'D' or 'U' or 'O' =>
+			n = 4;
+		's' or 'S' or 'r' or 'R' =>
+			print("'%c' format not yet supported\n", fmt);
+			continue;
+		'n' =>
+			print("\n");
+			continue;
+		'+' =>
+			dot++;
+			continue;
+		'-' =>
+			dot--;
+			continue;
+		'^' =>
+			dot -= n;
+			continue;
+		* =>
+			print("unknown format '%c'\n", fmt);
+			continue;
+		}
+		b := array[n] of byte;
+		v: int;
+		if(t == '=')
+			v = dot;
+		else {
+			sys->seek(mfd, big dot, Sys->SEEKSTART);
+			sys->read(mfd, b, len b);
+			v = 0;
+			for(i := 0; i < n; i++)
+				v |= int b[i] << (8*i);
+		}
+		case fmt {
+		'c' => print("%c", v);
+		'C' => print("%s", printable(v));
+		'b' => print("%#2.2ux ", v);
+		'x' => print("%#4.4ux ", v);
+		'X' => print("%#8.8ux ", v);
+		'd' => print("%-4d ", v);
+		'D' => print("%-8d ", v);
+		'u' => print("%-4ud ", v);
+		'U' => print("%-8ud ", v);
+		'o' => print("%s ", octal(v, 6));
+		'O' => print("%s ", octal(v, 11));
+		}
+		if(t != '=')
+			dot += n;
+	}
+	print("\n");
+}
+
+writemem(n: int, s: string)
+{
+	v: int;
+	ok: int;
+	s = eatws(s);
+	sys->seek(mfd, big dot, Sys->SEEKSTART);
+	for(;;) {
+		(s, v, ok) = getexpr(s);
+		if(!ok)
+			return;
+		b := array[n] of byte;
+		for(i := 0; i < n; i++)
+			b[i] = byte (v >> (8*i));
+		if (sys->write(mfd, b, len b) != len b)
+			sys->fprint(stderr, "mdb: write error: %r\n");
+	}
+}
+
+usage()
+{
+	sys->fprint(stderr, "usage: mdb [-w] file [command]\n");
+	raise "fail:usage";
+}
+
+writeable := 0;
+
+init(nil: ref Draw->Context, argv: list of string)
+{
+	sys = load Sys Sys->PATH;
+	stderr = sys->fildes(2);
+	str = load String String->PATH;
+	if (str == nil) {
+		sys->fprint(stderr, "mdb: cannot load %s: %r\n", String->PATH);
+		raise "fail:bad module";
+	}
+	bufio = load Bufio Bufio->PATH;
+	if (bufio == nil) {
+		sys->fprint(stderr, "mdb: cannot load %s: %r\n", Bufio->PATH);
+		raise "fail:bad module";
+	}
+
+	if (len argv < 2)
+		usage();
+	if (argv != nil)
+		argv = tl argv;
+	if (argv != nil && len hd argv && (hd argv)[0] == '-') {
+		if (hd argv != "-w")
+			usage();
+		writeable = 1;
+		argv = tl argv;
+	}
+	if (argv == nil)
+		usage();
+	fname := hd argv;
+	argv = tl argv;
+	cmd := "";
+	if(argv != nil)
+		cmd = hd argv;
+
+	oflags := Sys->OREAD;
+	if (writeable)
+		oflags = Sys->ORDWR;
+	mfd = sys->open(fname, oflags);
+	if(mfd == nil) {
+		sys->fprint(stderr, "mdb: cannot open %s: %r\n", fname);
+		raise "fail:cannot open";
+	}
+
+	if(cmd != nil)
+		docmd(cmd);
+	else {
+		stdin := bufio->fopen(sys->fildes(0), Sys->OREAD);
+		while ((s := stdin.gets('\n')) != nil) {
+			if (s[len s -1] == '\n')
+				s = s[0:len s - 1];
+			docmd(s);
+		}
+	}
+}