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URL: https://dev.to/black_tornado/you-have-been-zigged-series-reading-file-contents-3mcm

⇱ You have been zigged (series) : Reading text file contents - DEV Community

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();
}

Upon running this program using zig run filestdio_text__main.zig -- test.txt we can see the output in terminal (the contents of test.txt).

Thanks for reading. To be continued.