mm(1): rewritten in Rust

Makefile

@@ -114,8 +114,8 @@ build/bin/intcmp: src/intcmp.c build
 
 .PHONY: mm
 mm: build/bin/mm
-build/bin/mm: src/mm.c build
+build/bin/mm: src/mm.rs build rustlibs 
-	$(CC) $(CFLAGS) -o $@ src/mm.c
+	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/mm.rs
 
 .PHONY: npc
 npc: build/bin/npc

src/mm.c

@@ -1,236 +0,0 @@
-/*
- * Copyright (c) 2024 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 <signal.h> /* signal(2), SIG_ERR, SIG_IGN, SIGINT */
-#include <stdio.h> /* fclose(3), fopen(3), fprintf(3), getc(3), putc(3),
-                    * setvbuf(3), size_t, _IONBF, NULL */
-#include <stdlib.h> /* free(3), realloc(3) */
-#include <string.h> /* strcmp(3), strerror(3) */
-#include <unistd.h> /* getopt(3) */
-#if !defined EX_IOERR || !defined EX_OK || !defined EX_OSERR \
-		|| !defined EX_USAGE
-#	include <sysexits.h>
-#endif
-extern int errno;
-
-/* This structure is how open files are tracked. */
-struct Files{
-	size_t a;	/* allocation */
-	size_t s;	/* used size */
-	char *mode;	/* file opening mode */
-	char **names;	/* file names */
-	FILE **files;	/* file pointers */
-};
-
-/* How much to grow the allocation when it's saturated. */
-#ifndef ALLOC_INCREMENT
-#	define ALLOC_INCREMENT 1
-#endif
-
-/* How much to grow the allocation at program start. */
-#ifndef ALLOC_INITIAL
-#	define ALLOC_INITIAL 10
-#endif
-
-/* pre-allocated strings */
-static char *program_name = "<no argv[0]>";
-static char *stdin_name = "<stdin>";
-static char *stdout_name = "<stdout>";
-static char *stderr_name = "<stderr>";
-static char *(fmode[]) = { (char []){"rb"}, (char []){"rb+"} };
-static char *wharsh = "wb";
-
-/* Adds the open FILE pointer for the file at the path s to the files struct,
- * returning the FILE if successful and NULL if not, allocating more memory in
- * the files buffers as needed. */
-static FILE *
-Files_append(struct Files *files, FILE *file, char *name){
-
-	if(file == NULL || (files->s == files->a
-			&& ((files->files = realloc(files->files,
-					(files->a += (files->a == 0)
-						? ALLOC_INITIAL
-						: ALLOC_INCREMENT)
-					* sizeof *(files->files))) == NULL
-				|| (files->names = realloc(files->names,
-					files->a * sizeof *(files->names))) == NULL)))
-		return NULL;
-
-	files->names[files->s] = name;
-	return files->files[files->s++] = file;
-}
-
-/* Opens the file at the path p and puts it in the files struct, returning NULL
- * if either the opening or the placement of the open FILE pointer fail. */
-#define Files_open(files, p) \
-	Files_append((files), fopen((p), (files)->mode), (p))
-
-/* Prints a diagnostic message based on errno and returns an exit status
- * appropriate for an OS error. */
-static int
-oserr(char *s, char *r){
-
-	fprintf(stderr, "%s: %s: %s\n", s, r, strerror(errno));
-
-	return EX_OSERR;
-}
-
-/* Hijacks i and j from main and destructs the files[2] struct used by main by
- * closing its files and freeing its files and names arrays, returning retval
- * from main. */
-#define terminate \
-	for(i = 0; i < 2; ++i){ \
-		for(j = 0; j < files[i].s; ++j) \
-			if(files[i].files[j] != stdin \
-					&& files[i].files[j] != stdout \
-					&& files[i].files[j] != stderr) \
-				fclose(files[i].files[j]); \
-		free(files[i].files); \
-		free(files[i].names); \
-	} \
-	return retval
-
-/* Prints a usage text, in which s is the program being run (i.e. argv[0]), and
- * returns an exit status appropriate for a usage error. */
-int usage(char *s){
-
-	fprintf(stderr, "Usage: %s [-aenu] [-i input]... [-o output]...\n", s);
-
-	return EX_USAGE;
-}
-
-int main(int argc, char *argv[]){
-	int c;
-	struct Files files[2]; /* {read, write} */
-	size_t i;
-	size_t j;
-	size_t k; /* loop index but also unbuffer status */
-	int retval;
-
-	/* Initializes the files structs with their default values, standard
-	 * input and standard output. If an input or an output is specified
-	 * these initial values will be overwritten, so to, say, use mm(1)
-	 * equivalently to tee(1p), -o - will need to be specified before
-	 * additional files to ensure standard output is still written. */
-	for(i = 0; i < 2; ++i){
-		files[i].a = 0;
-		files[i].s = 0;
-		files[i].mode = fmode[i];
-		files[i].files = NULL;
-		files[i].names = NULL;
-		Files_append(&files[i], i == 0 ? stdin : stdout,
-			i == 0 ? stdin_name : stdout_name);
-		files[i].s = 0;
-	}
-
-	k = 0;
-
-	if(argc > 0)
-		program_name = argv[0];
-
-	if(argc > 1)
-		while((c = getopt(argc, argv, "aehi:no:u")) != -1)
-			switch(c){
-			case 'a': /* "rb+" -> "ab" */
-				files[1].mode[0] = 'a';
-				files[1].mode[2] = '\0';
-				break;
-			case 'e':
-				if(Files_append(&files[1], stderr, stderr_name) != NULL)
-					break;
-				retval = oserr(argv[0], "-e");
-				terminate;
-			case 'i':
-				if((strcmp(optarg, "-") == 0 && Files_append(&files[0],
-							stdin, stdin_name) != NULL)
-						|| Files_open(&files[0], optarg) != NULL)
-					break;
-				retval = oserr(argv[0], optarg);
-				terminate;
-			case 'o':
-				if((strcmp(optarg, "-") == 0 && Files_append(&files[1],
-							stdout, stdout_name) != NULL)
-						|| Files_open(&files[1], optarg) != NULL)
-					break;
-				/* does not exist, so try to create it */
-				if(errno == ENOENT){
-					files[1].mode = wharsh;
-					if(Files_open(&files[1], optarg) != NULL){
-						files[1].mode = fmode[1];
-						break;
-					}
-				}
-				retval = oserr(argv[0], optarg);
-				terminate;
-			case 'n':
-				if(signal(SIGINT, SIG_IGN) != SIG_ERR)
-					break;
-				retval = oserr(argv[0], "-n");
-				terminate;
-			case 'u':
-				k = 1;
-				break;
-			default:
-				retval = usage(argv[0]);
-				terminate;
-			}
-
-	if(optind != argc){
-		retval = usage(argv[0]);
-		terminate;
-	}
-
-	files[0].s += files[0].s == 0;
-	files[1].s += files[1].s == 0;
-	
-	/* Unbuffer files. */
-	if(k){
-		for(i = 0;
-			i < files[0].s;
-			setvbuf(files[0].files[i++], NULL, _IONBF, 0));
-		for(i = 0;
-			i < files[1].s;
-			setvbuf(files[1].files[i++], NULL, _IONBF, 0));
-	}
-
-	retval = EX_OK;
-
-	/* Actual program loop. */
-	for(i = 0; i < files[0].s; ++i) /* iterate ins */
-		while((c = getc(files[0].files[i])) != EOF) /* iterate chars */
-			for(j = 0; j < files[1].s; ++j) /* iterate outs */
-				if(putc(c, files[1].files[j]) == EOF){
-					/* notebook's full */
-					retval = EX_IOERR;
-					fprintf(stderr, "%s: %s: %s\n",
-						program_name, files[1].names[j], strerror(errno));
-					if(fclose(files[1].files[j]) == EOF)
-						fprintf(stderr, "%s: %s: %s\n",
-							program_name, files[1].names[j], strerror(errno));
-					/* massage out the tense muscle */
-					for(k = j--; k < files[1].s - 1; ++k){
-						files[1].files[k] = files[1].files[k+1];
-						files[1].names[k] = files[1].names[k+1];
-					}
-					if(--files[1].s == 0)
-						terminate;
-				}
-
-	terminate;
-}

src/mm.rs

@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2024 Emma Tebibyte <emma@tebibyte.media>
+ * 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/.
+ */
+
+use std::{
+	env::args,
+	fs::File,
+	io::{ stdin, stdout, stderr, BufWriter, Read, Write },
+	os::fd::{ AsRawFd, FromRawFd },
+	process::{ exit, ExitCode },
+};
+
+extern crate getopt;
+extern crate strerror;
+extern crate sysexits;
+
+use getopt::GetOpt;
+use strerror::StrError;
+use sysexits::{ EX_IOERR, EX_USAGE };
+
+fn main() -> ExitCode {
+	let argv = args().collect::<Vec<_>>();
+	let usage = format!("Usage: {} [-aeu] [-i input] [-o output]", argv[0]);
+
+	let mut a = false; /* append rather than update */
+	let mut e = false; /* use stderr as an output */
+	let mut u = false; /* unbuffer i/o */
+	let mut ins = Vec::new(); /* initial inputs vector */
+	let mut outs = Vec::new(); /* initial outputs vector */
+
+	while let Some(opt) = argv.getopt("aei:o:u") {
+		match opt.opt() {
+			Ok("a") => a = true,
+			Ok("e") =>  e = true, 
+			Ok("u") => u = true, 
+			Ok("i") => { /* add input */
+				let input = opt.arg().unwrap();
+				ins.push(input);
+			},
+			Ok("o") => { /* add output */
+				let output = opt.arg().unwrap(); 
+				outs.push(output);
+			},
+			Err(_) | Ok(_) => {
+				eprintln!("{}", usage);
+				return ExitCode::from(EX_USAGE as u8);
+			},
+		};
+	}
+
+	/* use stdin if no inputs are specified */
+	if ins.is_empty() { ins.push("-".to_string()); }
+
+	/* use stdout if no outputs are specified */
+	if outs.is_empty() { outs.push("-".to_string()); }
+	
+	/* map all path strings to files */
+	let inputs = ins.iter().map(|file| {
+		/* if a file is “-”, it is stdin */
+		if *file == "-" {
+			return unsafe { File::from_raw_fd(stdin().as_raw_fd()) }; /* fd0 = stdin */
+		}
+
+		match File::options().append(a).open(file) {
+			Ok(f) => f,
+			Err(e) => {
+				eprintln!("{}: {}", argv[0], e.strerror());
+				exit(EX_IOERR);
+			},
+		}
+	}).collect::<Vec<_>>();
+
+	/* map all path strings to files */
+	let mut outputs = outs.iter().map(|file| {
+		/* of a file is “-”, it is stdout */
+		if *file == "-" {
+			return unsafe { File::from_raw_fd(stdout().as_raw_fd()) }; /* fd1 = stdout */
+		}
+
+		match File::options().append(a).open(file) {
+			Ok(f) => return f,
+			Err(e) => {
+				eprintln!("{}: {}", argv[0], e.strerror());
+				exit(EX_IOERR);
+			},
+		};
+	}).collect::<Vec<_>>();
+
+	/* if -e is specified, use stderr */
+	if e {
+		outputs.push(unsafe { File::from_raw_fd(stderr().as_raw_fd()) }); /* fd2 = stderr */
+	}
+
+	let mut outputs = outputs.iter().map(|o| {
+		if u {
+			BufWriter::with_capacity(0, o)
+		} else {
+			BufWriter::new(o)
+		}
+	}).collect::<Vec<_>>();
+
+	for file in inputs {
+		for byte in file.bytes().map(|b| {
+			b.unwrap_or_else(|e| {
+				eprintln!("{}: {}", argv[0], e.strerror());
+				exit(EX_IOERR);
+			})
+		}) {
+			for out in &mut outputs {
+				if let Err(e) = out.write(&[byte]) {
+					eprintln!("{}: {}", argv[0], e.strerror());
+					return ExitCode::from(EX_IOERR as u8);
+				}
+				if let Err(e) = out.flush() {
+					eprintln!("{}: {}", argv[0], e.strerror());
+					return ExitCode::from(EX_IOERR as u8);
+				}
+			}
+		}
+	}
+
+	ExitCode::SUCCESS
+}