package core:compress/gzip

Source

package compress_gzip_example

import "core:compress"
import "core:compress/deflate"
import "core:fmt"
import "core:os"

// Small GZIP file with fextra, fname and fcomment present.
@private
TEST: []u8 = {
	0x1f, 0x8b, 0x08, 0x1c, 0xcb, 0x3b, 0x3a, 0x5a,
	0x02, 0x03, 0x07, 0x00, 0x61, 0x62, 0x03, 0x00,
	0x63, 0x64, 0x65, 0x66, 0x69, 0x6c, 0x65, 0x6e,
	0x61, 0x6d, 0x65, 0x00, 0x54, 0x68, 0x69, 0x73,
	0x20, 0x69, 0x73, 0x20, 0x61, 0x20, 0x63, 0x6f,
	0x6d, 0x6d, 0x65, 0x6e, 0x74, 0x00, 0x2b, 0x48,
	0xac, 0xcc, 0xc9, 0x4f, 0x4c, 0x01, 0x00, 0x15,
	0x6a, 0x2c, 0x42, 0x07, 0x00, 0x00, 0x00,
}

main :: proc() {
	// Set up output buffer.
	buf: [dynamic]byte
	defer delete(buf)

	stdout :: proc(s: string) {
		os.write_string(os.stdout, s)
	}
	stderr :: proc(s: string) {
		os.write_string(os.stderr, s)
	}

	if len(os.args) < 2 {
		stderr("No input file specified.\n")
		err := deflate.inflate_gzip(&buf, TEST)
		if err == nil {
			stdout("Displaying test vector: \"")
			stdout(string(buf[:]))
			stdout("\"\n")
		} else {
			fmt.printf("deflate.inflate_gzip returned %v\n", err)
		}
		delete(buf)
		os.exit(0)
	}

	for file in os.args[1:] {
		clear(&buf)
		err: deflate.Error

		if file == "-" {
			// Read from stdin
			ctx := compress.init_context(os.to_stream(os.stdin), &buf)
			defer compress.destroy_context(&ctx)
			err = deflate.inflate_gzip(&ctx)
		} else {
			data, read_err := os.read_entire_file(file, context.allocator)
			defer delete(data)
			if read_err != nil {
				stderr("File not found: ")
				stderr(file)
				stderr("\n")
				os.exit(1)
			}
			err = deflate.inflate_gzip(&buf, data)
		}
		if err != nil {
			stderr("GZIP returned an error.\n")
			os.exit(2)
		}
		stdout(string(buf[:]))
	}
}