20060303a

1 files changed, 96 insertions, 0 deletions

diff --git a/appl/cmd/sh/echo.b b/appl/cmd/sh/echo.b
new file mode 100644
index 00000000..2fa85def
--- /dev/null
+++ b/appl/cmd/sh/echo.b
@@ -0,0 +1,96 @@
+implement Shellbuiltin;
+
+include "sys.m";
+	sys: Sys;
+include "draw.m";
+include "sh.m";
+	sh: Sh;
+	Listnode, Context: import sh;
+	myself: Shellbuiltin;
+
+initbuiltin(ctxt: ref Context, shmod: Sh): string
+{
+	sys = load Sys Sys->PATH;
+	sh = shmod;
+	myself = load Shellbuiltin "$self";
+	if (myself == nil)
+		ctxt.fail("bad module", sys->sprint("echo: cannot load self: %r"));
+	ctxt.addbuiltin("echo", myself);
+	return nil;
+}
+
+whatis(nil: ref Sh->Context, nil: Sh, nil: string, nil: int): string
+{
+	return nil;
+}
+
+getself(): Shellbuiltin
+{
+	return myself;
+}
+
+runbuiltin(ctxt: ref Context, nil: Sh,
+			argv: list of ref Listnode, last: int): string
+{
+	case (hd argv).word {
+	"echo" =>
+		return builtin_echo(ctxt, argv, last);
+	}
+	return nil;
+}
+
+runsbuiltin(nil: ref Sh->Context, nil: Sh,
+			nil: list of ref Listnode): list of ref Listnode
+{
+	return nil;
+}
+
+argusage(ctxt: ref Context)
+{
+	ctxt.fail("usage", "usage: arg [opts {command}]... - args");
+}
+
+# converted from /appl/cmd/echo.b.
+# should have exactly the same semantics.
+builtin_echo(nil: ref Context, argv: list of ref Listnode, nil: int): string
+{
+	argv = tl argv;
+	nonewline := 0;
+	if (len argv > 0) {
+		w := (hd argv).word;
+		if (w == "-n" || w == "--") {
+			nonewline = (w == "-n");
+			argv = tl argv;
+		}
+	}
+	s := "";
+	if (argv != nil) {
+		s = word(hd argv);
+		for (argv = tl argv; argv != nil; argv = tl argv)
+			s += " " + word(hd argv);
+	}
+	if (nonewline == 0) 
+		s[len s] = '\n';
+	{
+		a := array of byte s;
+		if (sys->write(sys->fildes(1), a, len a) != len a) {
+			sys->fprint(sys->fildes(2), "echo: write error: %r\n");
+			return "write error";
+		}
+		return nil;
+	}
+	exception{
+		"write on closed pipe" =>
+			sys->fprint(sys->fildes(2), "echo: write error: write on closed pipe\n");
+			return "write error";
+	}
+}
+
+word(n: ref Listnode): string
+{
+	if (n.word != nil)
+		return n.word;
+	if (n.cmd != nil)
+		n.word = sh->cmd2string(n.cmd);
+	return n.word;
+}