66 lines
1.8 KiB
Zig
66 lines
1.8 KiB
Zig
const std = @import("std");
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const io = std.io;
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const mem = std.mem;
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const os = std.os;
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pub fn main() -> %void {
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const allocator = &std.debug.global_allocator;
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var args_it = os.args();
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const exe = %return unwrapArg(??args_it.next(allocator));
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var catted_anything = false;
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while (args_it.next(allocator)) |arg_or_err| {
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const arg = %return unwrapArg(arg_or_err);
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if (mem.eql(u8, arg, "-")) {
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catted_anything = true;
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%return cat_stream(&io.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 = io.InStream.open(arg, null) %% |err| {
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%%io.stderr.printf("Unable to open file: {}\n", @errorName(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(&io.stdin);
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}
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%return io.stdout.flush();
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}
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fn usage(exe: []const u8) -> %void {
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%%io.stderr.printf("Usage: {} [FILE]...\n", exe);
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return error.Invalid;
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}
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fn cat_stream(is: &io.InStream) -> %void {
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var buf: [1024 * 4]u8 = undefined;
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while (true) {
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const bytes_read = is.read(buf[0..]) %% |err| {
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%%io.stderr.printf("Unable to read from stream: {}\n", @errorName(err));
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return err;
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};
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if (bytes_read == 0) {
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break;
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}
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io.stdout.write(buf[0..bytes_read]) %% |err| {
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%%io.stderr.printf("Unable to write to stdout: {}\n", @errorName(err));
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return err;
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};
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}
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}
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fn unwrapArg(arg: %[]u8) -> %[]u8 {
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return arg %% |err| {
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%%io.stderr.printf("Unable to parse command line: {}\n", err);
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return err;
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};
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}
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