Add crc32 command

This is useful for checking the CRC-32 checksum of files used by the
loader. It outputs the checksum in signed decimal format, which is the
format used in the file name suffixes in the loader (e.g.
unpackclass_-1911426584.pack).

Signed-off-by: Graham <gpe@openrs2.dev>

all/build.gradle.kts

@@ -17,6 +17,7 @@ application {
 dependencies {
     implementation(project(":bundler"))
     implementation(project(":compress-cli"))
+    implementation(project(":crc32"))
     implementation(project(":decompiler"))
     implementation(project(":deob"))
     implementation(project(":deob-ast"))

all/src/main/java/dev/openrs2/Command.kt

@@ -4,6 +4,7 @@ import com.github.ajalt.clikt.core.CliktCommand
 import com.github.ajalt.clikt.core.subcommands
 import dev.openrs2.bundler.BundleCommand
 import dev.openrs2.compress.cli.CompressCommand
+import dev.openrs2.crc32.Crc32Command
 import dev.openrs2.decompiler.DecompileCommand
 import dev.openrs2.deob.DeobfuscateCommand
 import dev.openrs2.deob.ast.AstDeobfuscateCommand
@@ -12,6 +13,7 @@ import dev.openrs2.game.GameCommand
 fun main(args: Array<String>) = Command().subcommands(
     BundleCommand(),
     CompressCommand(),
+    Crc32Command(),
     DecompileCommand(),
     DeobfuscateCommand(),
     AstDeobfuscateCommand(),

crc32/build.gradle.kts

@@ -0,0 +1,29 @@
+plugins {
+    `maven-publish`
+    application
+    kotlin("jvm")
+}
+
+application {
+    mainClassName = "dev.openrs2.crc32.Crc32CommandKt"
+}
+
+dependencies {
+    api(project(":cli"))
+}
+
+publishing {
+    publications.create<MavenPublication>("maven") {
+        from(components["java"])
+
+        pom {
+            packaging = "jar"
+            name.set("OpenRS2 CRC-32")
+            description.set(
+                """
+                A tool for calculating the CRC-32 checksum of a file.
+            """.trimIndent()
+            )
+        }
+    }
+}

crc32/src/main/java/dev/openrs2/crc32/Crc32Command.kt

@@ -0,0 +1,32 @@
+package dev.openrs2.crc32
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.options.option
+import dev.openrs2.cli.defaultStdin
+import dev.openrs2.cli.inputStream
+import java.util.zip.CRC32
+
+fun main(args: Array<String>) = Crc32Command().main(args)
+
+class Crc32Command : CliktCommand(name = "crc32") {
+    private val input by option().inputStream().defaultStdin()
+
+    override fun run() {
+        val crc = CRC32()
+
+        input.use { input ->
+            val bytes = ByteArray(4096)
+
+            while (true) {
+                val len = input.read(bytes)
+                if (len == -1) {
+                    break
+                }
+
+                crc.update(bytes, 0, len)
+            }
+        }
+
+        echo(crc.value.toInt())
+    }
+}

settings.gradle.kts

@@ -10,6 +10,7 @@ include(
     "common",
     "compress",
     "compress-cli",
+    "crc32",
     "decompiler",
     "deob",
     "deob-annotations",