diff --git a/Makefile b/Makefile
index 5e2c70d..8f1f6d9 100644
--- a/Makefile
+++ b/Makefile
@@ -109,8 +109,8 @@ build/bin/hru: src/hru.rs build rustlibs
 
 .PHONY: intcmp
 intcmp: build/bin/intcmp
-build/bin/intcmp: src/intcmp.c build
-	$(CC) $(CFLAGS) -o $@ src/intcmp.c
+build/bin/intcmp: src/intcmp.rs build rustlibs
+	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/intcmp.rs
 
 .PHONY: mm
 mm: build/bin/mm
diff --git a/src/intcmp.c b/src/intcmp.c
deleted file mode 100644
index d6dff0d..0000000
--- a/src/intcmp.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright (c) 2023 DTB <trinity@trinity.moe>
- * SPDX-License-Identifier: AGPL-3.0-or-later
- *
- * This program is free software: you can redistribute it and/or modify it under
- * the terms of the GNU Affero General Public License as published by the Free
- * Software Foundation, either version 3 of the License, or (at your option) any
- * later version.
- * 
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
- * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
- * details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see https://www.gnu.org/licenses/.
- */
-
-#include <errno.h> /* errno */
-#include <stdio.h> /* fprintf(3), stderr */
-#include <stdlib.h> /* strtol(3), size_t, EXIT_FAILURE */
-#include <unistd.h> /* getopt(3), optind */
-#include <sysexits.h>
-
-/* 0b00? */		/*                     Equal | -e  | 0b001 | 1 */
-#define EQUAL	0x01	/*                   Greater | -g  | 0b010 | 2 */
-/* 0b0?0 */		/*          Greater or Equal | -ge | 0b011 | 3 */
-#define GREATER	0x02	/*                      Less | -l  | 0b100 | 4 */
-/* 0b?00 */		/*             Less or Equal | -le | 0b101 | 5 */
-#define LESS	0x04	/* Inequal (Greater or Less) | -gl | 0b110 | 6 */
-
-static char *program_name = "intcmp";
-
-int main(int argc, char *argv[]){
-	int c;
-	size_t i;
-	unsigned char mode;
-	int r; /* reference integer */
-
-	mode = 0;
-
-	if(argc < 3)
-		goto usage;
-
-	while((c = getopt(argc, argv, "egl")) != -1)
-		switch(c){
-		case 'e': mode |= EQUAL;   break;
-		case 'g': mode |= GREATER; break;
-		case 'l': mode |= LESS;	   break;
-		default:  goto usage;
-		}
-
-	if(optind + 2 /* ref cmp */ > argc){
-usage:		fprintf(stderr,
-			"Usage: %s [-egl] integer integer...\n",
-			argv[0] == NULL ? program_name : argv[0]);
-		return EX_USAGE;
-	}
-
-	i = optind;
-
-	do{	r = c;
-		c = strtol(argv[i], &argv[i], 10);
-		if(*argv[i] != '\0' || errno != 0){
-			fprintf(stderr, "%s: argument #%d: Invalid integer\n",
-				argv[0], (int)i);
-			return EX_USAGE;
-		}
-
-		if(i == optind)
-			continue;
-
-		/* rule enforcement; if a mode isn't permitted and the numbers
-		 * correspond to it, return 1 */
-		if(		(!(mode & EQUAL) && r == c)
-				|| (!(mode & GREATER) && r > c)
-				|| (!(mode & LESS) && r < c))
-			return 1;
-	}while(++i < argc);
-	
-	return 0;
-}
diff --git a/src/intcmp.rs b/src/intcmp.rs
index 470e751..88be72c 100644
--- a/src/intcmp.rs
+++ b/src/intcmp.rs
@@ -16,18 +16,17 @@
  * along with this program. If not, see https://www.gnu.org/licenses/.
  */
 
-// /* 0b00? */		/*                     Equal | -e  | 0b001 | 1 */
-// #define EQUAL	0x01	/*                   Greater | -g  | 0b010 | 2 */
-// /* 0b0?0 */		/*          Greater or Equal | -ge | 0b011 | 3 */
-// #define GREATER	0x02	/*                      Less | -l  | 0b100 | 4 */
-// /* 0b?00 */		/*             Less or Equal | -le | 0b101 | 5 */
-// #define LESS	0x04	/* Inequal (Greater or Less) | -gl | 0b110 | 6 */
-
 use std::{
 	env::args,
 	process::ExitCode
 };
 
+extern crate getopt;
+use getopt::GetOpt;
+
+extern crate sysexits;
+use sysexits::EX_USAGE;
+
 fn usage(s: &str) -> ExitCode {
 	eprintln!("Usage: {} [-egl] integer integer...", s);
 	ExitCode::from(EX_USAGE as u8)
@@ -54,7 +53,7 @@ fn main() -> ExitCode {
 
 	if argv.len() - optind < 2 /* ref cmp */ { return usage(&argv[0]); }
 
-	let mut reference = None;
+	let mut reference: Option<usize> = None;
 	let mut cmpn: usize;
 
 	for arg in argv.iter().skip(optind) {
@@ -72,6 +71,8 @@ fn main() -> ExitCode {
 					|| (!can_lt && refn < cmpn)
 				{ return ExitCode::FAILURE; }
 		}
+
+		reference = Some(cmpn);
 	}
 
 	ExitCode::SUCCESS