66 lines
1.6 KiB
Zig
66 lines
1.6 KiB
Zig
export executable "cat";
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import "std.zig";
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// Things to do to make this work:
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// * var args printing
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// * %void type
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// * defer
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// * %return
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// * %% operator
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// * make main return %void
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// * how to reference error values %.Invalid
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// * cast err type to string
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// * update std API
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pub %.Invalid;
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pub fn main(args: [][]u8) %void => {
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const exe = args[0];
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var catted_anything = false;
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for (arg, args[1...]) {
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if (arg == "-") {
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catted_anything = true;
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%return cat_stream(stdin);
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} else if (arg[0] == '-') {
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return usage(exe);
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} else {
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var is: InputStream;
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is.open(arg, OpenReadOnly) %% (err) => {
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stderr.print("Unable to open file: {}", ([]u8])(err));
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return err;
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}
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defer is.close();
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catted_anything = true;
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%return cat_stream(is);
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}
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}
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if (!catted_anything) {
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%return cat_stream(stdin)
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}
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}
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fn usage(exe: []u8) %void => {
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stderr.print("Usage: {} [FILE]...\n", exe);
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return %.Invalid;
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}
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fn cat_stream(is: InputStream) %void => {
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var buf: [1024 * 4]u8;
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while (true) {
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const bytes_read = is.read(buf);
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if (bytes_read < 0) {
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stderr.print("Unable to read from stream: {}", ([]u8)(is.err));
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return is.err;
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}
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const bytes_written = stdout.write(buf[0...bytes_read]);
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if (bytes_written < bytes_read) {
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stderr.print("Unable to write to stdout: {}", ([]u8)(stdout.err));
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return stdout.err;
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}
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}
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}
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