20060303a

1 files changed, 62 insertions, 0 deletions

diff --git a/appl/cmd/read.b b/appl/cmd/read.b
new file mode 100644
index 00000000..a4a008a9
--- /dev/null
+++ b/appl/cmd/read.b
@@ -0,0 +1,62 @@
+implement Read;
+include "sys.m"; 
+	sys: Sys;
+include "draw.m";
+
+Read: module {
+	init: fn(nil: ref Draw->Context, argv: list of string);
+};
+
+usage()
+{
+	sys->fprint(sys->fildes(2), "usage: read [-[ero] offset] count\n");
+	raise "fail:usage";
+}
+
+init(nil: ref Draw->Context, argv: list of string)
+{
+	sys = load Sys Sys->PATH;
+	# usage: read [-[ero] offset] count
+	count := Sys->ATOMICIO;
+	offset := big 0;
+	seeking := -1;
+	if (argv != nil)
+		argv = tl argv;
+	if (argv != nil && hd argv != nil && (hd argv)[0] == '-') {
+		if (tl argv == nil)
+			usage();
+		case hd argv {
+		"-o" =>
+			seeking = Sys->SEEKSTART;
+		"-e" =>
+			seeking = Sys->SEEKEND;
+		"-r" =>
+			seeking = Sys->SEEKRELA;
+		* =>
+			usage();
+		}
+		offset = big hd tl argv;
+		argv = tl tl argv;
+	}
+	if (argv != nil) {
+		if (tl argv != nil)
+			usage();
+		count = int hd argv;
+	}
+	fd := sys->fildes(0);
+	if (seeking != -1)
+		sys->seek(fd, offset, seeking);
+	if (count == 0)
+		return;
+	buf := array[count] of byte;
+	n := sys->read(fd, buf, len buf);
+	if (n > 0)
+		sys->write(sys->fildes(1), buf, n);
+	else {
+		if (n == -1) {
+			sys->fprint(sys->fildes(2), "read: read error: %r\n");
+			raise "fail:error";
+		}
+		raise "fail:eof";
+	}
+}