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cat.zig: simplification.

This commit is contained in:
Philippe Pittoli 2022-05-01 00:41:11 +02:00
parent 444078fcc6
commit 7204ade9e3

View File

@ -1,57 +1,34 @@
const std = @import("std"); const std = @import("std");
const stdout = std.io.getStdOut().writer();
fn print(comptime format: []const u8, args: anytype) void {
const stdout = std.io.getStdOut().writer();
nosuspend stdout.print(format, args) catch return;
}
fn print_input() !void {
const stdin = std.io.getStdIn().reader();
var buffer: [4096]u8 = undefined;
while (true) {
const nbytes = try stdin.read(&buffer);
print("{s}", .{buffer[0..nbytes]});
if (nbytes == 0) break;
}
}
fn fatal(comptime format: []const u8, args: anytype) noreturn {
std.log.err(format, args);
std.process.exit(1);
}
const usage = "usage: cat [files]";
pub fn main() anyerror!void { pub fn main() anyerror!void {
const args = try std.process.argsAlloc(std.heap.page_allocator); const args = try std.process.argsAlloc(std.heap.page_allocator);
if (args.len <= 1) { if (args.len <= 1) {
std.log.info("{s}", .{usage}); try print_input();
fatal("expected command argument", .{});
} }
const files = args[1..]; for (args[1..]) |f| {
for (files) |f| { if (std.mem.eql(u8, f, "-")) { try print_input(); }
if (std.mem.eql(u8, f, "-")) { else { try print_file (f); }
try print_input();
}
else {
try print_file (f);
}
} }
} }
fn print_input() !void {
try print_all (std.io.getStdIn());
}
fn print_file(dest: []const u8) !void { fn print_file(dest: []const u8) !void {
// open file and defer closing var file = try std.fs.cwd().openFile(dest, .{ .mode = .read_only });
var file = try std.fs.cwd().openFile(dest, .{ .mode = .read_only }); defer file.close();
defer file.close(); try print_all (file);
}
// read file content and print everything
var buffer: [4096]u8 = undefined; fn print_all(reader: std.fs.File) !void {
var nbytes : u64 = 0; var buffer: [4096]u8 = undefined;
while (true) { while (true) {
nbytes = try file.read(&buffer); const nbytes = try reader.read(&buffer);
print("{s}", .{buffer[0..nbytes]}); try stdout.print("{s}", .{buffer[0..nbytes]});
if (nbytes == 0) break; if (nbytes == 0) break;
} }
} }