20060303a

1 files changed, 55 insertions, 0 deletions

diff --git a/appl/lib/wait.b b/appl/lib/wait.b
new file mode 100644
index 00000000..f24be0f2
--- /dev/null
+++ b/appl/lib/wait.b
@@ -0,0 +1,55 @@
+implement Wait;
+
+#
+# Copyright © 2003 Vita Nuova Holdings Limited.  All rights reserved.
+#
+
+include "sys.m";
+	sys: Sys;
+
+include "wait.m";
+
+init()
+{
+	sys = load Sys Sys->PATH;
+}
+
+read(fd: ref Sys->FD): (int, string, string)
+{
+	buf := array[2*Sys->WAITLEN] of byte;
+	n := sys->read(fd, buf, len buf);
+	if(n <= 0)
+		return (n, nil, sys->sprint("%r"));
+	return parse(string buf[0:n]);
+}
+
+monitor(fd: ref Sys->FD): (int, chan of (int, string, string))
+{
+	pid := chan of int;
+	out := chan of (int, string, string);
+	spawn waitreader(fd, pid, out);
+	return (<-pid, out);
+}
+
+waitreader(fd: ref Sys->FD, pid: chan of int, out: chan of (int, string, string))
+{
+	pid <-= sys->pctl(0, nil);
+	for(;;){
+		(child, modname, status) := read(fd);
+		out <-= (child, modname, status);
+		if(child <= 0)
+			break;	# exit on error
+	}
+}
+
+parse(status: string): (int, string, string)
+{
+	for (i := 0; i < len status; i++)
+		if (status[i] == ' ')
+			break;
+	j := i+2;	# skip space and "
+	for (i = j; i < len status; i++)
+		if (status[i] == '"')
+			break;
+	return (int status, status[j:i], status[i+2:]);
+}