fileis.1: rename from scrut.1

Makefile

@@ -29,10 +29,10 @@ RUSTC ?= rustc
 RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
 	--extern sysexits=build/o/libsysexits.rlib \
 	--extern strerror=build/o/libstrerror.rlib
-CFLAGS += -I$(SYSEXITS)
+CFLAGS += -I$(SYSEXITS) -Iinclude
 
 .PHONY: all
-all: dj false fop hru intcmp mm npc rpn scrut str strcmp swab true
+all: dj false fileis fop hru intcmp mm npc rpn scrut str strcmp swab true
 
 # keep build/include until bindgen(1) has stdin support
 # https://github.com/rust-lang/rust-bindgen/issues/2703
@@ -97,6 +97,11 @@ false: build/bin/false
 build/bin/false: src/false.c build
 	$(CC) $(CFLAGS) -o $@ src/false.c
 
+.PHONY: fileis
+fileis: build/bin/fileis
+build/bin/fileis: src/fileis.rs build
+	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/fileis.rs
+
 .PHONY: fop
 fop: build/bin/fop
 build/bin/fop: src/fop.rs build rustlibs
@@ -114,8 +119,8 @@ build/bin/intcmp: src/intcmp.c build
 
 .PHONY: mm
 mm: build/bin/mm
-build/bin/mm: src/mm.rs build rustlibs 
-	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/mm.rs
+build/bin/mm: src/mm.c build
+	$(CC) $(CFLAGS) -o $@ src/mm.c
 
 .PHONY: npc
 npc: build/bin/npc
@@ -127,11 +132,6 @@ rpn: build/bin/rpn
 build/bin/rpn: src/rpn.rs build rustlibs
 	$(RUSTC) $(RUSTFLAGS) $(RUSTLIBS) -o $@ src/rpn.rs
 
-.PHONY: scrut
-scrut: build/bin/scrut
-build/bin/scrut: src/scrut.c build
-	$(CC) $(CFLAGS) -o $@ src/scrut.c
-
 .PHONY: str
 str: build/bin/str
 build/bin/str: src/str.c build

docs/fileis.1

@@ -4,12 +4,12 @@
 .\" 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 SCRUT 1 2024-06-06 "Harakit X.X.X"
+.TH SCRUT 1 2024-07-18 "Harakit X.X.X"
 .SH NAME
-scrut \(en scrutinize file properties
+fileis \(en scrutinize file properties
 .SH SYNOPSIS
 
-scrut
+fileis
 .RB [ -LSbcdefgkprsuwx ]
 .B file...
 .\"
@@ -82,5 +82,6 @@ Copyright \(co 2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
 .\"
 .SH SEE ALSO
 .BR access (3p),
+.BR chown (1p),
 .BR lstat (3p),
 .BR test (1p)

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 2024-07-14 "Harakit X.X.X"
+.TH MM 1 2024-06-17 "Harakit X.X.X"
 .SH NAME
 mm \(en middleman
 .\"
 .SH SYNOPSIS
 
 mm
-.RB [ -aetu ]
+.RB [ -aenu ]
 .RB [ -i\ input ]
 .RB [ -o\ output ]
 .\"
@@ -21,25 +21,19 @@ Catenate input files and write them to the start of each output file or stream.
 .SH OPTIONS
 
 .IP \fB-a\fP
-Opens outputs for appending rather than updating.
+Opens subsequent outputs for appending rather than updating.
 .IP \fB-e\fP
 Use the standard error as an output.
-.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-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.
+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 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.
+no outputs are specified, the standard output shall be used.
+.IP \fB-u\fP
+Ensures neither input or output will be buffered.
+.IP \fB-n\fP
+Causes SIGINT signals to be ignored.
 .\"
 .SH DIAGNOSTICS
 
@@ -51,6 +45,10 @@ 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

include/libfileis.h

@@ -0,0 +1,14 @@
+int fileis_block  (char *fn);
+int fileis_char   (char *fn);
+int fileis_dir    (char *fn);
+/*  fileis_exec   (char *fn); */
+int fileis_exists (char *fn);
+int fileis_fifo   (char *fn);
+int fileis_setgid (char *fn);
+int fileis_link   (char *fn);
+/*  fileis_read   (char *fn); */
+int fileis_regular(char *fn);
+int fileis_socket (char *fn);
+int fileis_setuid (char *fn);
+int fileis_vtx    (char *fn);
+/*  fileis_write  (char *fn); */

src/fileis.rs

@@ -0,0 +1,87 @@
+/*
+ * 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::metadata,
+	os::unix::fs::{ FileTypeExt, MetadataExt },
+	process::ExitCode,
+};
+
+extern crate getopt;
+use getopt::GetOpt;
+
+extern crate sysexits;
+use sysexits::EX_USAGE;
+
+fn usage(s: &str) -> ExitCode {
+	eprintln!("Usage: {} [-bcdefgkprsuwxLS] file...", s);
+	ExitCode::from(EX_USAGE as u8)
+}
+
+fn main() -> ExitCode {
+	let argv = args().collect::<Vec<String>>();
+
+	let mut sel = String::from(""); // selected options
+	let mut optind: usize = 1; // argv[0]
+
+	while let Some(opt) = argv.getopt("bcdefgkprsuwxLS") {
+		if let Ok(optchr) = opt.opt() { sel.push_str(optchr); }
+		else { return usage(&argv[0]); }
+
+		optind = opt.ind();
+	}
+
+	if optind == argv.len() { return usage(&argv[0]); }
+
+	for arg in argv.iter().skip(optind) {
+		let fmeta; // file metadata
+		let fmode; // file mode; see chmod(1p)
+		let ftype; // file type
+
+		match metadata(arg) {
+			Ok(m) => fmeta = m,
+			_ => { return ExitCode::FAILURE; } // no perms or nonexistent
+		}
+
+		fmode = fmeta.mode();
+		ftype = fmeta.file_type();
+
+		for selection in sel.chars() { // run all selected tests
+			match selection {
+				'b' if ftype.is_block_device() => (),
+				'c' if ftype.is_char_device() => (),
+				'e' => (), // exists or metadata would have errored
+				'd' if fmeta.is_dir() => (),
+				'f' if fmeta.is_file() => (),
+				'g' if fmode & 0o2000 /* S_ISGID */ != 0 => (), // setgid
+				'k' if fmode & 0o1000 /* S_ISVTX */ != 0 => (), // setvtx
+				'p' if ftype.is_fifo() => (),
+				'r' if fmode & 0o0400 /* S_IRUSR */ != 0 => (), // read access
+				'u' if fmode & 0o4000 /* S_ISUID */ != 0 => (), // setuid
+				'w' if fmode & 0o0200 /* S_IWUSR */ != 0 => (), // write access
+				'x' if fmode & 0o0100 /* S_IXUSR */ != 0 => (), // exec access
+				'L' if fmeta.is_symlink() => (),
+				'S' if ftype.is_socket() => (),
+				_ => { return ExitCode::FAILURE; }
+			}
+		}
+	}
+
+	ExitCode::SUCCESS
+}

src/mm.c

@@ -0,0 +1,236 @@
+/*
+ * 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

@@ -1,185 +0,0 @@
-/*
- * 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/scrut.c

@@ -1,107 +0,0 @@
-/*
- * Copyright (c) 2023–2024 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
- * 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 <stdio.h> /* fprintf(3), stderr, NULL */
-#include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS */
-#include <string.h> /* memset(3), strchr(3) */
-#ifndef EX_USAGE
-#	include <sysexits.h>
-#endif
-#include <unistd.h> /* access(3), getopt(3), F_OK, R_OK, W_OK, X_OK */
-#include <sys/stat.h> /* lstat(3), stat struct, S_ISBLK, S_ISCHR, S_ISDIR,
-                       * S_ISFIFO, S_ISGID, S_ISREG, S_ISLNK, S_ISSOCK,
-                       * S_ISUID, S_ISVTX */
-
-static char args[] = "bcdefghkprsuwxLS";
-static char ops[(sizeof args) / (sizeof *args)];
-static char *program_name = "scrut";
-
-int main(int argc, char *argv[]){
-	struct stat buf;
-	int c;
-	size_t i;
-	char *p;
-
-	if(argc < 2)
-		goto usage;
-
-	memset(ops, '\0', sizeof ops);
-	while((c = getopt(argc, argv, args)) != -1)
-		if((p = strchr(args, c)) == NULL)
-			goto usage;
-		else
-			ops[p - args] = c;
-	/* straighten out ops */
-	for(i = 0, p = ops; i < (sizeof ops) / (sizeof *ops); ++i)
-		if(ops[i] != '\0'){
-			*p = ops[i];
-			if(&ops[i] != p++)
-				ops[i] = '\0';
-		}
-
-	if(optind == argc)
-		goto usage;
-
-	argv += optind;
-	do{	if(access(*argv, F_OK) != 0 || lstat(*argv, &buf) == -1)
-			return EXIT_FAILURE; /* doesn't exist or isn't stattable */
-
-		for(i = 0; ops[i] != '\0'; ++i)
-			if(ops[i] == 'e')
-				continue;
-			else if(ops[i] == 'h'){
-usage:				fprintf(stderr, "Usage: %s [-%s] file...\n",
-					argv[0] == NULL
-						? program_name
-						: argv[0],
-					args);
-
-				return EX_USAGE;
-			}else if(
-					(ops[i] == 'b'
-						&& !S_ISBLK(buf.st_mode))
-					|| (ops[i] == 'c'
-						&& !S_ISCHR(buf.st_mode))
-					|| (ops[i] == 'd'
-						&& !S_ISDIR(buf.st_mode))
-					|| (ops[i] == 'f'
-						&& !S_ISREG(buf.st_mode))
-					|| (ops[i] == 'g'
-						&& !(buf.st_mode & S_ISGID))
-					|| (ops[i] == 'k'
-						&& !(buf.st_mode & S_ISVTX))
-					|| (ops[i] == 'p'
-						&& !S_ISFIFO(buf.st_mode))
-					|| (ops[i] == 'r'
-						&& access(*argv, R_OK) != 0)
-					|| (ops[i] == 'u'
-						&& !(buf.st_mode & S_ISUID))
-					|| (ops[i] == 'w'
-						&& access(*argv, W_OK) != 0)
-					|| (ops[i] == 'x'
-						&& access(*argv, X_OK) != 0)
-					|| (ops[i] == 'L'
-						&& !S_ISLNK(buf.st_mode))
-					|| (ops[i] == 'S'
-						&& !S_ISSOCK(buf.st_mode)))
-				return EXIT_FAILURE;
-	}while(*++argv != NULL);
-
-	return EXIT_SUCCESS;
-}