1 files changed, 144 insertions, 0 deletions
diff --git a/appl/cmd/fs/readfile.b b/appl/cmd/fs/readfile.b
new file mode 100644
index 00000000..4a52ae08
--- /dev/null
+++ b/appl/cmd/fs/readfile.b
@@ -0,0 +1,144 @@
+implement Fsmodule;
+include "sys.m";
+	sys: Sys;
+include "draw.m";
+include "sh.m";
+include "fslib.m";
+	fslib: Fslib;
+	Report, Value, type2s, report, quit: import fslib;
+	Fschan, Fsdata, Entrychan, Entry,
+	Gatechan, Gatequery, Nilentry, Option,
+	Next, Down, Skip, Quit: import Fslib;
+
+this is a bad idea, i think
+i think walk + filter + setroot is good enough.
+
+types(): string
+{
+	# usage: readfile [-f file] name
+	return "xs-fs";
+}
+
+badmod(p: string)
+{
+	sys->fprint(sys->fildes(2), "fs: readfile: cannot load %s: %r\n", p);
+	raise "fail:bad module";
+}
+
+init()
+{
+	sys = load Sys Sys->PATH;
+	fslib = load Fslib Fslib->PATH;
+	if(fslib == nil)
+		badmod(Fslib->PATH);
+}
+
+run(nil: ref Draw->Context, report: ref Report,
+			opts: list of Option, args: list of ref Value): ref Value
+{
+	path: string;
+	f := (hd args).s().i;
+	fd: ref Sys->FD;
+	seekable: int;
+	if(f == "-"){
+		if(opts == nil){
+			sys->fprint(sys->fildes(2), "fs: readfile: must specify a path when reading stdin\n");
+			return nil;
+		}
+		fd = sys->fildes(0);
+		seekable = 0;
+	}else{
+		fd = sys->open(f, Sys->OREAD);
+		seekable = isseekable(fd);
+	}
+	if(fd == nil){
+		sys->fprint(sys->fildes(2), "fs: readfile: cannot open %s: %r\n", f);
+		return nil;
+	}
+	if(opts != nil)
+		path = (hd (hd opts).args).s().i;
+	else
+		path = f;
+
+	(root, file) := pathsplit(path);
+	if(file == nil || file == "." || file == ".."){
+		sys->fprint(sys->fildes(2), "fs: readfile: invalid filename %q\n", fname);
+		return nil;
+	}
+	d.name = file;
+	v := ref Value.X(chan of (Fsdata, chan of int));
+	spawn readproc(v.i, fd, root, ref d, seekable, report.start("read"));
+	return v;
+}
+
+readproc(c: Fschan, fd: ref Sys->FD, root: string, d: ref Sys->Dir, seekable: int, errorc: chan of string)
+{
+	reply := chan of int;
+	rd := ref Sys->nulldir;
+	rd.name = root;
+	c <-= ((rd, nil), reply);
+	if(<-reply != Down)
+		quit(errorc);
+
+	c <-= ((d, nil), reply);
+	case <-reply {
+	Down =>
+		sendfile(c, fd, errorc);
+	Skip or
+	Quit =>
+		quit(errorc);
+	}
+	c <-= ((nil, nil), reply);
+	<-reply;
+	quit(errorc);
+}
+
+sendfile(c: Fschan, data: list of array of byte, length: big, errorc: chan of string)
+{
+	reply := chan of int;
+	for(;;){
+		buf: array of byte;
+		if(fd != nil){
+			buf := array[Sys->ATOMICIO] of byte;
+			if((n := sys->read(fd, buf, len buf)) <= 0){
+			if(n < 0)
+				report(errorc, sys->sprint("read error: %r"));
+			c <-= ((nil, nil), reply);
+			if(<-reply == Quit)
+				quit(errorc);
+			return;
+		}
+		c <-= ((nil, buf), reply);
+		case <-reply {
+		Quit =>
+			quit(errorc);
+		Skip =>
+			return;
+		}
+	}
+}
+
+pathsplit(p: string): (string, string)
+{
+	for (i := len p - 1; i >= 0; i--)
+		if (p[i] != '/')
+			break;
+	if (i < 0)
+		return (p, nil);
+	p = p[0:i+1];
+	for (i = len p - 1; i >=0; i--)
+		if (p[i] == '/')
+			break;
+	if (i < 0)
+		return (".", p);
+	return (p[0:i+1], p[i+1:]);
+}
+
+# dodgy heuristic... avoid, or using the stat-length of pipes and net connections
+isseekable(fd: ref Sys->FD): int
+{
+	(ok, stat) := sys->stat(iob.fd);
+	if(ok != -1 && stat.dtype == '|' || stat.dtype == 'I')
+		return 0;
+	return 1;
+}