peek(1): use stdbool.h

I could trace strcmp(1) as far back as
<293436c5ad/src/streq.c>
in my repo.

Makefile

@@ -32,7 +32,7 @@ RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
 CFLAGS += -I$(SYSEXITS)
 
 .PHONY: all
-all: dj false fop hru intcmp mm npc rpn scrut str strcmp swab true
+all: docs dj false fop hru intcmp mm npc peek rpn scrut str strcmp swab true
 
 # keep build/include until bindgen(1) has stdin support
 # https://github.com/rust-lang/rust-bindgen/issues/2703
@@ -109,18 +109,23 @@ 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
-build/bin/mm: src/mm.c build
-	$(CC) $(CFLAGS) -o $@ src/mm.c
+build/bin/mm: src/mm.rs build rustlibs 
+	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/mm.rs
 
 .PHONY: npc
 npc: build/bin/npc
 build/bin/npc: src/npc.c build
-	$(CC) $(CFLAGAS) -o $@ src/npc.c
+	$(CC) $(CFLAGS) -o $@ src/npc.c
+
+.PHONY: peek
+peek: build/bin/peek
+build/bin/peek: src/peek.c build
+	$(CC) $(CFLAGS) -o $@ src/peek.c
 
 .PHONY: rpn
 rpn: build/bin/rpn

docs/mm.1

@@ -3,14 +3,14 @@
 .\" This work is licensed under CC BY-SA 4.0. To see a copy of this license,
 .\" visit <http://creativecommons.org/licenses/by-sa/4.0/>.
 .\"
-.TH MM 1 2024-06-17 "Harakit X.X.X"
+.TH MM 1 2024-07-14 "Harakit X.X.X"
 .SH NAME
 mm \(en middleman
 .\"
 .SH SYNOPSIS
 
 mm
-.RB [ -aenu ]
+.RB [ -aetu ]
 .RB [ -i\ input ]
 .RB [ -o\ output ]
 .\"
@@ -21,19 +21,25 @@ Catenate input files and write them to the start of each output file or stream.
 .SH OPTIONS
 
 .IP \fB-a\fP
-Opens subsequent outputs for appending rather than updating.
+Opens outputs for appending rather than updating.
 .IP \fB-e\fP
 Use the standard error as an output.
-.IP \fB-i\fP\ \fIinput\fP
-Opens a path as an input. If one or more of the input files is \(lq-\(rq or if
-no inputs are specified, the standard input shall be used.
-.IP \fB-o\fP\ \fIoutput\fP
-Opens a path as an output. If one or more of the output files is \(lq-\(rq or if
-no outputs are specified, the standard output shall be used.
+.IP \fB-t\fP
+Causes outputs to be overwritten instead of being truncated.
 .IP \fB-u\fP
 Ensures neither input or output will be buffered.
-.IP \fB-n\fP
-Causes SIGINT signals to be ignored.
+.IP \fB-i\fP\ \fIinput\fP
+Opens a path as an input. If one or more of the input files is \(lq-\(rq or if
+no inputs are specified, the standard input shall be used. If specified as the
+last option and if there are trailing arguments to the program, they shall be
+appended to the list of files to use as inputs.
+.IP \fB-o\fP\ \fIoutput\fP
+Opens a path as an output. If one or more of the output files is \(lq-\(rq or if
+no outputs are specified and the
+.B -e
+option is not specified, the standard output shall be used. If specified as the
+last option and if there are trailing arguments to the program, they shall be
+appended to the list of files to use as outputs.
 .\"
 .SH DIAGNOSTICS
 
@@ -45,10 +51,6 @@ exits with the appropriate
 .BR sysexits.h (3)
 status.
 .\"
-.SH CAVEATS
-
-Existing files are not truncated on ouput and are instead overwritten.
-.\"
 .SH RATIONALE
 
 The

docs/peek.1

@@ -0,0 +1,111 @@
+.\" Copyright (c) 2023-2024 DTB <trinity@trinity.moe>
+.\" Copyright (c) 2024 Emma Tebibyte <emma@tebibyte.media>
+.\"
+.\" This work is licensed under CC BY-SA 4.0. To see a copy of this license,
+.\" visit <http://creativecommons.org/licenses/by-sa/4.0/>.
+.\"
+.TH PEEK 1 2024-08-14 "Harakit X.X.X"
+.SH NAME
+peek \(en read from the standard input, furtively
+.\"
+.SH SYNOPSIS
+
+peek
+.RB ( -i )
+.\"
+.SH DESCRIPTION
+
+Read input from the standard input with terminal echo disabled.
+.\"
+.SH OPTIONS
+
+.IP \fB-i\fP
+Allows input to come from sources other than terminals (pipes).
+.\"
+.SH DIAGNOSTICS
+
+In the event of an error, a debug message will be printed and the program will
+exit with the appropriate
+.BR sysexits.h (3)
+error code.
+
+In order to ensure the user\(cqs terminal is still usable after premature
+termination, the program attempts to handle the SIGINT signal; if it cannot,
+an error message is printed and execution continues. If the program is
+interrupted, it exits unsuccessfully without an error message.
+.\"
+.SH RATIONALE
+
+This tool was originally written to accept passwords in shell scripts as an
+extremely simple alternative to the GNU Privacy Guard project\(cqs
+.BR pinentry (1)
+utility.
+
+Accepting input without showing what is being typed is useful when keying in
+secrets in public settings or in places where surveillance cameras are
+installed.
+.\"
+.SH CAVEATS
+
+This program does nothing to prevent others from seeing the key presses input to
+a keyboard. It also does not protect against the sound of typing being analyzed
+to determine what was input without needing to see screen or keyboard.
+
+Accepting secrets in shell scripts is probably not advisable.
+
+On systems that support it, the
+.BR ioctl (2)
+command TIOCSTI can be used to insert characters into the standard input. This
+doesn't allow snooping but can be used for general mischief.
+.\"
+.SH EXAMPLES
+
+This is an
+.BR sh (1p)
+command line that hashes a given password. It uses
+.BR head (1p)
+to only accept one line of input,
+.BR xargs (1p)
+and
+.BR printf (1p)
+to strip the trailing newline,
+.BR htpasswd (1) 
+from Apache\(cqs utilities to hash the input with the bcrypt algorithm, and
+.BR cut (1p)
+to print only the resulting hash:
+
+.RS
+$ peek | head -n 1 | xargs printf '%s' | htpasswd -nBi _ | cut -d : -f 2
+.RE
+
+This is an
+.BR sh (1p)
+command line that allows a user to write blindly into a text file but displaying
+only written lines. Some writers have the habit of prematurely revising their 
+work and use tools with functionality similar to this to prevent it. 
+It uses
+.BR mm (1)
+to pipe the output of the program to both the standard error and the regular
+file writing.txt:
+
+.RS
+$ echo Input ^D to quit. && peek | mm -eo - >writing.txt
+.RE
+.\"
+.SH AUTHOR
+
+Written by DTB
+.MT trinity@trinity.moe
+.ME .
+.\"
+.SH COPYRIGHT
+
+Copyright \(co 2023-2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
+<https://gnu.org/licenses/gpl.html>.
+.\"
+.SH SEE ALSO
+.BR ioctl (2),
+.BR ioctl_tty (2),
+.BR read (1p),
+.BR sh (1p),
+.BR stty (1p)

docs/strcmp.1

@@ -4,7 +4,7 @@
 .\" This work is licensed under CC BY-SA 4.0. To see a copy of this license,
 .\" visit <http://creativecommons.org/licenses/by-sa/4.0/>.
 .\"
-.TH STRCMP 1 2024-06-17 "Harakit X.X.X"
+.TH STRCMP 1 2024-07-15 "Harakit X.X.X"
 .SH NAME
 strcmp \(en compare strings
 .\"
@@ -20,15 +20,15 @@ Check whether string arguments are the same.
 .SH DIAGNOSTICS
 
 The program will exit successfully if the strings are identical. Otherwise, it
-will exit with an error code of 1 if a string passed has a lesser byte value
-than one of the prior strings:
+will exit with an error code less than 128 if a string passed has a lesser byte
+value than one of the prior strings:
 
 .RS
 strcmp b a
 .RE
 
-or with an error code of 255 if it has a greater byte value than one of the
-prior strings:
+or with an error code greater than 128 if it has a greater byte value than one
+of the prior strings:
 
 .RS
 strcmp a b

docs/swab.1

@@ -11,7 +11,6 @@ swab \(en swap bytes
 .SH SYNOPSIS
 
 swab
-.RB [ -f ]
 .RB [ -w\ word_size ]
 .\"
 .SH DESCRIPTION
@@ -20,8 +19,6 @@ Swap the latter and former halves of a block of bytes.
 .\"
 .SH OPTIONS
 
-.IP \fB-f\fP
-Ignore SIGINT signal.
 .IP \fB-w\fP\ \fIword_size\fP
 Configures the word size; that is, the size in bytes of the block size on which
 to operate. The default word size is 2. The word size must be cleanly divisible

src/dj.c

@@ -263,12 +263,12 @@ int main(int argc, char *argv[]){
 		assert(io[0].bufuse == 0);
 
 		{ /* read */
-			char skipping;
+			long skipping;
 			size_t t;
 
 			/* hack to intentionally get a partial read from Io_read */
-			if((skipping = (io[0].seek > 0)) && io[0].seek < io[0].bs)
-				io[0].bufuse = io[0].bs - io[0].seek;
+			if((skipping = MIN(io[0].seek, io[0].bs)) > 0)
+				io[0].bufuse = io[0].bs - (size_t)skipping;
 
 			t = io[0].bufuse;
 			if(Io_read(&io[0])->bufuse == t && !noerror && io[0].error == 0)
@@ -290,7 +290,8 @@ int main(int argc, char *argv[]){
 				}
 			}
 
-			if(skipping){
+			if(skipping > 0){
+				io[0].seek -= skipping;
 				io[0].bufuse = 0;
 				count += (count != 0);
 				continue;

src/intcmp.c

@@ -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;
-}

src/intcmp.rs

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2023–2024 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/.
+ */
+
+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)
+}
+
+fn main() -> ExitCode {
+	let argv = args().collect::<Vec<String>>();
+	let mut e = false; /* args can be == */
+	let mut g = false; /* args can be > */
+	let mut l = false; /* args can be < */
+	let mut optind = 0;
+
+	if argv.len() < 3 { return usage(&argv[0]); }
+
+	while let Some(opt) = argv.getopt("egl") {
+		match opt.opt() {
+			Ok("e") => e = true,
+			Ok("g") => g = true,
+			Ok("l") => l = true,
+			_ => { return usage(&argv[0]); },
+		}
+		optind = opt.ind();
+	}
+
+	if argv.len() - optind < 2 /* see usage */ { return usage(&argv[0]); }
+
+	let mut prev: Option<usize> = None; /* no previous operand */
+	let mut currn: usize;
+
+	for arg in argv.iter().skip(optind) { /* iterate operands */
+		match arg.parse::<usize>() { /* parse current operand */
+			Ok(n) => currn = n,
+			_ => {
+				eprintln!("{}: {}: Invalid integer", &argv[0], arg);
+				return ExitCode::from(EX_USAGE as u8);
+			}
+		}
+
+		if let Some(prevn) = prev { /* if there was a previous opr., test */
+			if (!e && prevn == currn)
+					|| (!g && prevn > currn)
+					|| (!l && prevn < currn)
+				{ return ExitCode::FAILURE; }
+		}
+
+		prev = Some(currn); /* there is a previous operand */
+	}
+
+	ExitCode::SUCCESS
+}

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 +1,185 @@
+/*
+ * Copyright (c) 2024 Emma Tebibyte <emma@tebibyte.media>
+ * 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/.
+ */
+
+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 };
+
+use ArgMode::*;
+
+enum ArgMode { In, Out }
+
+fn main() -> ExitCode {
+	let argv = args().collect::<Vec<_>>();
+	let usage = format!("Usage: {} [-aetu] [-i input] [-o output]", argv[0]);
+
+	let mut a = false; /* append to the file */
+	let mut e = false; /* use stderr as an output */
+	let mut t = true; /* do not truncate the file before writing */
+	let mut u = false; /* unbuffer i/o */
+	let mut ins = Vec::new(); /* initial input file path vector */
+	let mut outs = Vec::new(); /* initial output file path vector */
+	let mut mode: Option<ArgMode> = None; /* mode set by last-used option */
+	let mut optind = 0;
+
+	while let Some(opt) = argv.getopt("aei:o:tu") {
+		match opt.opt() {
+			Ok("a") => a = true,
+			Ok("e") => e = true, 
+			Ok("u") => u = true,
+			Ok("t") => t = false,
+			Ok("i") => { /* add inputs */
+				let input = opt.arg().unwrap();
+				ins.push(input);
+				mode = Some(In); /* latest argument == -i */
+			},
+			Ok("o") => { /* add output */
+				let output = opt.arg().unwrap(); 
+				outs.push(output);
+				mode = Some(Out); /* latest argument == -o */
+			},
+			Err(_) | Ok(_) => {
+				eprintln!("{}", usage);
+				return ExitCode::from(EX_USAGE as u8);
+			},
+		};
+
+		optind = opt.ind();
+	}
+
+	let remaining = argv.iter().skip(optind);
+
+	/* check the last flag specified */
+	if let Some(m) = mode {
+		for arg in remaining {
+			/* move the subsequent arguments to the list of inputs or outputs */
+			match m {
+				In => ins.push(arg.to_string()),
+				Out => outs.push(arg.to_string()),
+			};
+		}
+	} else {
+		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() && !e { 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 == "-" {
+			/* portable way to access stdin as a file */
+			return unsafe { File::from_raw_fd(stdin().as_raw_fd()) };
+		}
+
+		match File::open(file) {
+			Ok(f) => f,
+			Err(e) => {
+				eprintln!("{}: {}: {}", argv[0], file, 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 == "-" {
+			/* portable way to access stdout as a file */
+			return unsafe { File::from_raw_fd(stdout().as_raw_fd()) }; 
+		}
+
+		let options = File::options()
+			/* don’t truncate if -t is specified, append if -a is specified */
+			.truncate(t)
+			.append(a)
+			/* enable the ability to create and write to files */
+			.create(true)
+			.write(true)
+			/* finally, open the file! */
+			.open(file);
+
+		match options {
+			Ok(f) => return f,
+			Err(e) => {
+				eprintln!("{}: {}: {}", argv[0], file, e.strerror());
+				exit(EX_IOERR);
+			},
+		};
+	}).collect::<Vec<_>>();
+
+	/* if -e is specified, use stderr */
+	if e {
+		/* portable way to access stderr as a file */
+		outputs.push(unsafe { File::from_raw_fd(stderr().as_raw_fd()) });
+	}
+
+	let mut outputs = outputs.iter().map(|o| {
+		if u {
+			/* unbuffered writing through a buffer of capacity 0 */
+			BufWriter::with_capacity(0, o)
+		} else {
+			/* theoretically buffered writing */
+			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 u {
+					/* immediately flush the output for -u */
+					if let Err(e) = out.flush() { 
+						eprintln!("{}: {}", argv[0], e.strerror());
+						return ExitCode::from(EX_IOERR as u8);
+					}
+				}
+			}
+		}
+	}
+
+	ExitCode::SUCCESS
+}

src/peek.c

@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2023–2024 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 <signal.h> /* sigaction(2), signal(2), struct sigaction, SIGINT */
+#include <stdbool.h> /* bool */
+#include <stdio.h> /* fprintf(3), fgetc(3), perror(3), fputc(3), stderr, stdin,
+                    * stdout, EOF, NULL */
+#include <stdlib.h> /* exit(3), EXIT_FAILURE */
+#include <sysexits.h> /* EX_IOERR, EX_OK, EX_USAGE */
+#include <termios.h> /* tcgetattr(3), tcsetattr(3), struct termios, ECHO */
+#include <unistd.h> /* getopt(3), isatty(3), pledge(2), unveil(2),
+                     * STDIN_FILENO */
+
+char *program_name = "peek";
+
+/* Restores terminal echo; otherwise when a user ^Cs the terminal would
+ * continue to not display typed text. If sig isn't zero, this will terminate
+ * the program. */
+static void
+restore_echo(int sig) {
+	static struct termios t;
+
+	/* Failure isn't reported because this is the termination routine anyway;
+	 * errors will be obvious. */
+	if (tcgetattr(STDIN_FILENO, &t) == 0) {
+		t.c_lflag |= ECHO;
+		(void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &t);
+	}
+
+	if (sig != 0) { exit(EXIT_FAILURE); } /* Terminated by signal. */
+
+	return;
+}
+
+static int
+ioerr(char *argv0) {
+	perror(argv0);
+	restore_echo(0);
+	return EX_IOERR;
+}
+
+static int
+usage(char *argv0) {
+	(void)fprintf(stderr, "Usage: %s [-i]\n", argv0);
+
+	return EX_USAGE;
+}
+
+int main(int argc, char *argv[]){
+#ifdef __OpenBSD__
+	if (pledge("stdio tty unveil", "") != 0 || unveil(NULL, NULL) != 0) {
+		/* This isn't fatal; these return values could be cast to void just as
+		 * easily. */
+		(void)perror(argv[0] == NULL ? argv[0] : program_name);
+	}
+#endif
+
+	if (argc > 0) { /* option parsing */
+		bool allow_nonterminals;
+		int c;
+
+		program_name = argv[0];
+
+		allow_nonterminals = 0;
+		while ((c = getopt(argc, argv, "i")) != -1) {
+			switch (c) {
+				case 'i':	allow_nonterminals = 1; break;
+				default:	return usage(argv[0]);
+			}
+		}
+
+		if (argc > optind) { return usage(argv[0]); }
+
+		if (!allow_nonterminals && isatty(STDIN_FILENO) != 1) {
+			(void)fprintf(
+			    stderr,
+			    "%s: Must be run in a terminal (specify -i to skip this"
+			    " check)\n",
+			    argv[0]
+			);
+			return EX_USAGE;
+		}
+	}
+
+	{ /* Install signal handler */
+		/* There isn't a difference in functionality between the signal(2) and
+		 * sigaction(2) methods. sigaction(2) is vastly preferred for
+		 * portability but some configurations can only use signal(2). */
+		/* Errors aren't terminating because the worst that happens is some
+		 * terminal phooeyness if things go awry. */
+#if defined _POSIX_C_SOURCE
+		struct sigaction act = { 0 };
+
+		act.sa_handler = restore_echo;
+		if (sigaction(SIGINT, &act, NULL) != 0) { perror(program_name); }
+#else
+		if (signal(SIGINT, restore_echo) == SIG_ERR) { perror(program_name); }
+#endif
+	}
+
+	/* Banish terminal echo; this terminates when it fails, because it's the
+	 * whole point of the program. */
+	{
+		struct termios t;
+
+		if (tcgetattr(STDIN_FILENO, &t) != 0) { return ioerr(program_name); }
+		t.c_lflag ^= ECHO;
+		if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t) != 0) {
+			return ioerr(program_name);
+		}
+	}
+
+	{ /* Input loop */
+		int c;
+
+		while ((c = fgetc(stdin)) != EOF) {
+			if (fputc(c, stdout) == EOF) { return ioerr(program_name); }
+		}
+	}
+
+	restore_echo(0);
+
+	return EX_OK;
+}

src/strcmp.c

@@ -1,24 +1,43 @@
-#include <stdio.h> /* fprintf(3), stderr */
-#include <stdlib.h> /* EXIT_FAILURE */
-#include <sysexits.h>
+/*
+ * Copyright (c) 2022–2024 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/.
+ */
 
-static char *program_name = "strcmp";
+#include <stdio.h> /* fprintf(3), stderr */
+#include <stdlib.h> /* size_t */
+#include <sysexits.h> /* EX_USAGE */
+
+char *program_name = "strcmp";
 
 int main(int argc, char *argv[]){
-	int i;
-
-	if(argc < 3){
+	if (argc < 3) {
 		fprintf(stderr, "Usage: %s string string...\n",
-			argv[0] == NULL ? program_name : argv[0]);
+			argv[0] == NULL ? program_name : argv[0]
+		);
 		return EX_USAGE;
 	}
 
-	for(; *argv[1] != '\0'; ++argv[1])
-		for(i = 2; i < argc; ++i)
-			if(*argv[i-1] > *argv[i])
-				return 1;
-			else if(*argv[i-1] < *argv[i]++)
-				return -1; /* actually 255 */
+	/* This compares the Nth character of arg[2] onward with argv[1]'s Nth
+	 * character, rather than comparing each arg with argv[1] sequentially. */
+	for (; *argv[1] != '\0'; ++argv[1]) { /* iterate chars in argv[1] */
+		for (size_t i = 2; i < argc; ++argv[i], ++i) { /* iterate &argv[2] */
+			/* this never overruns because of nul termination */
+			if (*argv[i-1] != *argv[i]) { return *argv[i-1] - *argv[i]; }
+		}
+	}
 
 	return 0;
 }

src/swab.rs

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2024 DTB <trinity@trinity.moe>
+ * 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
@@ -18,7 +19,7 @@
 
 use std::{
 	env::args,
-	io::{ stdin, stdout, Error, ErrorKind, Read, Write },
+	io::{ stdin, stdout, Error, Read, Write },
 	process::ExitCode,
 	vec::Vec
 };
@@ -38,7 +39,7 @@ fn oserr(s: &str, e: Error) -> ExitCode {
 }
 
 fn usage(s: &str) -> ExitCode {
-	eprintln!("Usage: {} [-f] [-w word_size]", s);
+	eprintln!("Usage: {} [-w word_size]", s);
 	ExitCode::from(EX_USAGE as u8)
 }
 
@@ -48,24 +49,26 @@ fn main() -> ExitCode {
 	let mut input = stdin();
 	let mut output = stdout().lock();
 
-	let mut force = false;
-	let mut wordsize: usize = 2;
+	let mut optind: usize = 1;   // argv[0]
+	let mut wordsize: usize = 2; // Equivalent to dd(1p).
 
-	while let Some(opt) = argv.getopt("fw:") {
+	while let Some(opt) = argv.getopt("w:") {
 		match opt.opt() {
-			Ok("f") => force = true,
 			Ok("w") => {
-				if let Some(arg) = opt.arg() {
-					match arg.parse::<usize>() {
-						Ok(w) if w % 2 == 0 => { wordsize = w; () },
+					match opt.arg().unwrap().parse::<usize>() {
+						Ok(w) if w % 2 == 0 => { wordsize = w; },
 						_ => { return usage(&argv[0]); },
 					}
-				}
+				optind = opt.ind();
 			},
 			_ => { return usage(&argv[0]); }
 		}
 	}
 
+	if optind < argv.len() {
+		return usage(&argv[0]);
+	}
+
 	buf.resize(wordsize, 0);
 
 	loop {
@@ -83,7 +86,6 @@ fn main() -> ExitCode {
 					break oserr(&argv[0], e)
 				}
 			},
-			Err(e) if e.kind() == ErrorKind::Interrupted && force => continue,
 			Err(e) => break oserr(&argv[0], e)
 		}
 	}