hautils

commit cf3272fc2d1559247b1777b9b780a120285f6c0f
parent 4c35f03fc6bf45a28326c48cd9a94b02f31c0e5b
Author: Drew DeVault <sir@cmpwn.com>
Date:   Thu,  8 Jul 2021 14:19:35 -0400

tee: new command

Diffstat:
M
.gitignore
 | 
1
+
M
Makefile
 | 
2
++
M
main/main.ha
 | 
4
+++-
A
tee.ha
 | 
49
+++++++++++++++++++++++++++++++++++++++++++++++++

4 files changed, 55 insertions(+), 1 deletion(-)
diff --git a/.gitignore b/.gitignore
@@ -1,3 +1,4 @@
 cat
 false
 true
+tee
diff --git a/Makefile b/Makefile
@@ -5,6 +5,7 @@ HARE=hare
 utils=\
 	cat \
 	false \
+	tee \
 	true
 
 all: $(utils)
@@ -20,4 +21,5 @@ clean:
 
 cat: cat.ha main/main.ha
 false: false.ha
+tee: tee.ha
 true: true.ha
diff --git a/main/main.ha b/main/main.ha
@@ -2,7 +2,9 @@ use fmt;
 use fs;
 use io;
 
-@symbol("utilmain") fn utilmain() (io::error | fs::error | void);
+export type error = (io::error | fs::error);
+
+@symbol("utilmain") fn utilmain() (main::error | void);
 
 // Shared main function for all utilities, to simplify error handling.
 export @symbol("main") fn main() void = {
diff --git a/tee.ha b/tee.ha
@@ -0,0 +1,49 @@
+use fmt;
+use fs;
+use getopt;
+use io;
+use main;
+use os;
+
+export fn utilmain() (main::error | void) = {
+	const cmd = getopt::parse(os::args,
+		"read from standard input and write to standard output and files",
+		('a', "append the output to the files"),
+		('i', "ignore the SIGINT signal"),
+		"file...",
+	);
+	defer getopt::finish(&cmd);
+
+	let flags = fs::flags::WRONLY;
+	for (let i = 0z; i < len(cmd.opts); i += 1) {
+		const opt = cmd.opts[i];
+		switch (opt.0) {
+			'a' => flags |= fs::flags::APPEND,
+			'i' => abort("TODO: Ignore SIGINT"),
+			*   => abort(), // Invariant
+		};
+	};
+
+	let source = os::stdin;
+	let files: []*io::stream = [];
+	defer {
+		for (let i = 0z; i < len(files); i += 1) {
+			io::close(files[i]);
+		};
+		free(files);
+	};
+
+	for (let i = 0z; i < len(cmd.args); i += 1) {
+		const file = match (os::create(cmd.args[i], 0o666, flags)) {
+			err: fs::error => fmt::fatal(
+				"Error opening '{}' for writing: {}",
+				cmd.args[i], fs::strerror(err)),
+			file: *io::stream => file,
+		};
+		source = io::tee(source, file);
+		append(files, file);
+	};
+
+	io::copy(os::stdout, source)?;
+	return;
+};