You have been zigged (series) : Reading text file contents

#zig

Lets explore how to read contents of a text file and print it out in stdout. To do this we will use Dir.openFile() function and Reader.takeDelimiterExclusive() function. Lets first save a demo text file as test.txt in the same folder as where the program lives and have some lorem ipsum in it.

// filestdio_text__main.zig
const std = @import("std");

pub fn main(init: std.process.Init) !void {
    var stderr_buffer: [1024]u8 = undefined;
    var stderr_file_writer = std.Io.File.Writer.init(std.Io.File.stderr(), init.io, &stderr_buffer);
    const stderr_writer = &stderr_file_writer.interface;

    const commandline_args = try init.minimal.args.toSlice(init.arena.allocator());
    if (commandline_args.len != 2) { // exe name and filename
        try stderr_writer.print("Usage: filestdio_text__main <filename>\n", .{});
        try stderr_writer.flush();
        return;
    }

    const file = try std.Io.Dir.cwd().openFile(init.io, commandline_args[1], .{});

    var file_buffer: [1024]u8 = undefined;
    var file_file_reader = std.Io.File.Reader.init(file, &file_buffer);
    var file_reader = &file_file_reader.interface;
    const file_content = try file_reader.takeDelimiterExclusive('\x00');

    var stdout_buffer: [1024]u8 = undefined;
    var stdout_file_writer = std.Io.File.Writer.init(std.Io.File.stdout(), init.io, &stdout_buffer);
    const stdout_writer = &stdout_file_writer.interface;

    try stdout_writer.print("{s}", .{file_content});
    try stdout_writer.flush();
}