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Evan Burkey 2024-11-06 10:47:07 -08:00
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24
.gitignore vendored Normal file
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# This file is for zig-specific build artifacts.
# If you have OS-specific or editor-specific files to ignore,
# such as *.swp or .DS_Store, put those in your global
# ~/.gitignore and put this in your ~/.gitconfig:
#
# [core]
# excludesfile = ~/.gitignore
#
# Cheers!
# -andrewrk
.zig-cache/
zig-out/
/release/
/debug/
/build/
/build-*/
/docgen_tmp/
# Although this was renamed to .zig-cache, let's leave it here for a few
# releases to make it less annoying to work with multiple branches.
zig-cache/
.idea/

52
build.zig Normal file
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const std = @import("std");
// Although this function looks imperative, note that its job is to
// declaratively construct a build graph that will be executed by an external
// runner.
pub fn build(b: *std.Build) void {
// Standard target options allows the person running `zig build` to choose
// what target to build for. Here we do not override the defaults, which
// means any target is allowed, and the default is native. Other options
// for restricting supported target set are available.
const target = b.standardTargetOptions(.{});
// Standard optimization options allow the person running `zig build` to select
// between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
// set a preferred release mode, allowing the user to decide how to optimize.
const optimize = b.standardOptimizeOption(.{});
const exe = b.addExecutable(.{
.name = "baze64",
.root_source_file = b.path("src/main.zig"),
.target = target,
.optimize = optimize,
});
// This declares intent for the executable to be installed into the
// standard location when the user invokes the "install" step (the default
// step when running `zig build`).
b.installArtifact(exe);
// This *creates* a Run step in the build graph, to be executed when another
// step is evaluated that depends on it. The next line below will establish
// such a dependency.
const run_cmd = b.addRunArtifact(exe);
// By making the run step depend on the install step, it will be run from the
// installation directory rather than directly from within the cache directory.
// This is not necessary, however, if the application depends on other installed
// files, this ensures they will be present and in the expected location.
run_cmd.step.dependOn(b.getInstallStep());
// This allows the user to pass arguments to the application in the build
// command itself, like this: `zig build run -- arg1 arg2 etc`
if (b.args) |args| {
run_cmd.addArgs(args);
}
// This creates a build step. It will be visible in the `zig build --help` menu,
// and can be selected like this: `zig build run`
// This will evaluate the `run` step rather than the default, which is "install".
const run_step = b.step("run", "Run the app");
run_step.dependOn(&run_cmd.step);
}

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build.zig.zon Normal file
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.{
// This is the default name used by packages depending on this one. For
// example, when a user runs `zig fetch --save <url>`, this field is used
// as the key in the `dependencies` table. Although the user can choose a
// different name, most users will stick with this provided value.
//
// It is redundant to include "zig" in this name because it is already
// within the Zig package namespace.
.name = "baze64",
// This is a [Semantic Version](https://semver.org/).
// In a future version of Zig it will be used for package deduplication.
.version = "0.0.0",
// This field is optional.
// This is currently advisory only; Zig does not yet do anything
// with this value.
//.minimum_zig_version = "0.11.0",
// This field is optional.
// Each dependency must either provide a `url` and `hash`, or a `path`.
// `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
// Once all dependencies are fetched, `zig build` no longer requires
// internet connectivity.
.dependencies = .{
// See `zig fetch --save <url>` for a command-line interface for adding dependencies.
//.example = .{
// // When updating this field to a new URL, be sure to delete the corresponding
// // `hash`, otherwise you are communicating that you expect to find the old hash at
// // the new URL.
// .url = "https://example.com/foo.tar.gz",
//
// // This is computed from the file contents of the directory of files that is
// // obtained after fetching `url` and applying the inclusion rules given by
// // `paths`.
// //
// // This field is the source of truth; packages do not come from a `url`; they
// // come from a `hash`. `url` is just one of many possible mirrors for how to
// // obtain a package matching this `hash`.
// //
// // Uses the [multihash](https://multiformats.io/multihash/) format.
// .hash = "...",
//
// // When this is provided, the package is found in a directory relative to the
// // build root. In this case the package's hash is irrelevant and therefore not
// // computed. This field and `url` are mutually exclusive.
// .path = "foo",
//
// // When this is set to `true`, a package is declared to be lazily
// // fetched. This makes the dependency only get fetched if it is
// // actually used.
// .lazy = false,
//},
},
// Specifies the set of files and directories that are included in this package.
// Only files and directories listed here are included in the `hash` that
// is computed for this package. Only files listed here will remain on disk
// when using the zig package manager. As a rule of thumb, one should list
// files required for compilation plus any license(s).
// Paths are relative to the build root. Use the empty string (`""`) to refer to
// the build root itself.
// A directory listed here means that all files within, recursively, are included.
.paths = .{
"build.zig",
"build.zig.zon",
"src",
// For example...
//"LICENSE",
//"README.md",
},
}

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src/base64.zig Normal file
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const std = @import("std");
const stdout = std.io.getStdOut().writer();
pub const err = error{
IndexNotFound,
};
pub const Base64 = struct {
table: *const [64]u8,
pub const init: Base64 = .{
.table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
};
fn char_at(self: Base64, index: u8) u8 {
return self.table[index];
}
pub fn encode(self: Base64, allocator: std.mem.Allocator, input: []const u8) ![]u8 {
if (input.len == 0) {
return "";
}
const encode_length = try calc_encode_length(input);
var out = try allocator.alloc(u8, encode_length);
var buf = [3]u8{0, 0, 0};
var count: u16 = 0;
var outc: u16 = 0;
for (input) |b| {
buf[count] = b;
count += 1;
if (count == 3) {
out[outc] = self.char_at(buf[0] >> 2);
out[outc + 1] = self.char_at(((buf[0] & 0x03) << 4) + (buf[1] >> 4));
out[outc + 2] = self.char_at(((buf[1] & 0x0F) << 2) + (buf[2] >> 6));
out[outc + 3] = self.char_at(buf[2] & 0x3F);
count = 0;
outc += 4;
}
}
if (count == 2) {
out[outc] = self.char_at(buf[0] >> 2);
out[outc + 1] = self.char_at((buf[0] & 0x03) << 4) + (buf[1] >> 4);
out[outc + 2] = self.char_at((buf[1] & 0x0F) << 2);
out[outc + 3] = '=';
} else if (count == 1) {
out[outc] = self.char_at(buf[0] >> 2);
out[outc + 1] = self.char_at((buf[0] & 0x03) << 4);
out[outc + 2] = '=';
out[outc + 3] = '=';
}
return out;
}
fn decode_index(self: Base64, char: u8) err!u8 {
if (char == '=') {
return 64;
}
if (char >= 'A' and char <= 'Z') {
return char - 'A';
} else if (char >= 'a' and char <= 'z') {
return char - 'a' + 26;
} else {
for (52..64) |i| {
const idx: u8 = @intCast(i);
if (self.char_at(idx) == char) {
return idx;
}
}
}
return err.IndexNotFound;
}
pub fn decode(self: Base64, allocator: std.mem.Allocator, input: []const u8) ![]u8 {
if (input.len == 0) {
return "";
}
const output_sz = try calc_decode_length(input);
var output = try allocator.alloc(u8, output_sz);
var count: u8 = 0;
var iout: u64 = 0;
var buf = [4]u8{ 0, 0, 0, 0 };
for (0..input.len) |i| {
buf[count] = try self.decode_index(input[i]);
count += 1;
if (count == 4) {
output[iout] = (buf[0] << 2) + (buf[1] >> 4);
if (buf[2] != 64) {
output[iout + 1] = (buf[1] << 4) + (buf[2] >> 2);
}
if (buf[3] != 64) {
output[iout + 2] = (buf[2] << 6) + buf[3];
}
iout += 3;
count = 0;
}
}
return output;
}
};
fn calc_encode_length(input: []const u8) !usize {
if (input.len < 3) {
return 4;
}
const n_output: usize = try std.math.divCeil(usize, input.len, 3);
return n_output * 4;
}
fn calc_decode_length(input: []const u8) !usize {
if (input.len < 4) {
return 3;
}
const n_output: usize = try std.math.divFloor(usize, input.len, 4);
return n_output * 3;
}
test "encode hello" {
var b = Base64.init;
var gpa = std.heap.GeneralPurposeAllocator(.{}).init;
const allocator = gpa.allocator();
const encoded = try b.encode(allocator, "hello");
try std.testing.expect(std.mem.eql(u8, encoded, "aGVsbG8="));
}
test "encode long" {
var b = Base64.init;
var gpa = std.heap.GeneralPurposeAllocator(.{}).init;
const allocator = gpa.allocator();
const encoded = try b.encode(allocator, "Hey, it's me. I'm the problem. It's me");
try std.testing.expect(std.mem.eql(u8, encoded, "SGV5LCBpdCdzIG1lLiBJJ20gdGhlIHByb2JsZW0uIEl0J3MgbWU="));
}
test "decode hello" {
var b = Base64.init;
var gpa = std.heap.GeneralPurposeAllocator(.{}).init;
const allocator = gpa.allocator();
const encoded = try b.decode(allocator, "aGVsbG8=");
try stdout.print("{s}\n", .{encoded});
try std.testing.expect(std.mem.eql(u8, encoded, "hello"));
}
test "decode long" {
var b = Base64.init;
var gpa = std.heap.GeneralPurposeAllocator(.{}).init;
const allocator = gpa.allocator();
const encoded = try b.decode(allocator, "SGV5LCBpdCdzIG1lLiBJJ20gdGhlIHByb2JsZW0uIEl0J3MgbWU=");
try stdout.print("{s}\n", .{encoded});
try std.testing.expect(std.mem.eql(u8, encoded, "Hey, it's me. I'm the problem. It's me"));
}
test "decode_index" {
var b = Base64.init;
try std.testing.expectError(err.IndexNotFound, b.decode_index('{'));
var r :u8 = 0;
r = try b.decode_index('A');
try std.testing.expect(r == 0);
r = try b.decode_index('a');
try std.testing.expect(r == 26);
r = try b.decode_index('0');
try std.testing.expect(r == 52);
r = try b.decode_index('/');
try std.testing.expect(r == 63);
r = try b.decode_index('=');
try std.testing.expect(r == 64);
}

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const std = @import("std");
const stdout = std.io.getStdOut().writer();
const b64 = @import("base64.zig");
const usageText =
\\Usage: baze64 {-d/-D} input
\\Args:
\\ -d -D: decode instead of encode
;
pub fn main() !void {
var gpa = std.heap.GeneralPurposeAllocator(.{}).init;
const allocator = gpa.allocator();
var args = try std.process.argsWithAllocator(allocator);
defer args.deinit();
var b = b64.Base64.init;
// Skip arg[0]
_ = args.skip();
var a = args.next();
if (a) |arg| {
if (std.mem.eql(u8, arg, "-d") or std.mem.eql(u8, arg, "-D")) {
a = args.next();
const decoded = try b.decode(allocator, arg);
try stdout.print("{s}", .{decoded});
} else {
const encoded = try b.decode(allocator, arg);
try stdout.print("{s}", .{encoded});
}
} else {
try stdout.print("{s}", .{usageText});
}
}