made dj options no longer alphabetized

.editorconfig

@@ -12,6 +12,3 @@ indent_size = 2
 
 [*.sh]
 indent_size = 2
-
-[configure]
-indent_size = 2

.gitignore

@@ -1,3 +1,2 @@
 build/
 dist/
-*.mk

CONTRIBUTING

@@ -90,26 +90,44 @@ notice:
  *     USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-When writing code, make sure lines never exceed 80 characters in width when
-using four-character-wide indentation steps.
+Make sure lines never exceed 80 columns in width when using four-character
+indentation steps. This helps contributors with smaller screens, those using
+side-by-side editor windows or panes, and those who have no text wrapping in
+their editor or terminal.
 
-For usage text and help messages, please do not implement a -h option. Just
-print usage information when any erroneous option is specified. Follow the
-NetBSD style guide for usage text output format [1].
+For usage text and help messages, do not implement a -h option. Instead, print
+usage information when any erroneous option is specified. Follow the NetBSD
+style guide for the usage text’s output format [1].
 
-If committing a new source file for a utility, format the commit message like
-this:
+[1] <http://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/src/share/misc/style>
 
-$ git commit -m 'tool(1): <information>'
+If committing a new source file, format the commit message following these
+guidelines:
+
+$ git commit -m 'tool(1): add feature x'
 
 If committing a new library or header file:
 
-$ git commit -m 'library(1): <information>'
+$ git commit -m 'library(3): fix overflow'
+$ git commit -m 'header.h(3): add header.h(3)'
+
+If committing a new manual page:
+
+$ git commit -m 'tool.1: add author details'
 
 If modifying some other file or directory:
 
-$ git commit -m 'README: clarification'
-$ git commit -m 'tests: posix: fixed bug #47'
-$ git commit -m 'docs: tool(1): added author information'
+$ git commit -m 'README: clarify'
+$ git commit -m 'tests/posix: fix bug #47'
 
-etc.
+For multiple of these:
+
+$ git commit -m 'Makefile, tool(1): add tool(1)'
+$ git commit -m 'tool(1): add tool(1); library(3), library.3: add library(3)'
+$ git commit -m 'tool(1): fix #42 & add feature x'
+
+Commit messages should be written in the present tense.
+
+--
+This work © 2023–2024 by Emma Tebibyte is licensed under CC BY-SA 4.0. To view a
+copy of this license, visit <http://creativecommons.org/licenses/by-sa/4.0/>

Makefile

@@ -17,7 +17,7 @@ CC=cc
 RUSTC=rustc
 
 .PHONY: all
-all: dj false fop intcmp scrut str strcmp true
+all: dj false fop hru intcmp mm rpn scrut str strcmp swab true
 
 build:
 	# keep build/include until bindgen(1) has stdin support
@@ -40,7 +40,6 @@ install: dist
 
 .PHONY: test
 test: build
-	tests/cc-compat.sh
 	tests/posix-compat.sh
 	$(RUSTC) --test src/getopt-rs/lib.rs -o build/test/getopt
 
@@ -55,7 +54,7 @@ build/o/libsysexits.rlib: build
 		| $(RUSTC) $(RUSTFLAGS) --crate-type lib -o build/o/libsysexits.rlib -
 
 build/o/libgetopt.rlib: src/getopt-rs/lib.rs
-	$(RUSTC) $(RUSTCFLAGS) --crate-type=lib --crate-name=getopt \
+	$(RUSTC) $(RUSTFLAGS) --crate-type=lib --crate-name=getopt \
 		-o build/o/libgetopt.rlib src/getopt-rs/lib.rs
 
 .PHONY: dj
@@ -75,11 +74,23 @@ build/bin/fop: src/fop.rs build build/o/libgetopt.rlib build/o/libsysexits.rlib
 		--extern sysexits=build/o/libsysexits.rlib \
 		-o $@ src/fop.rs
 
+.PHONY: hru
+hru: build/bin/hru
+build/bin/hru: src/hru.rs build build/o/libgetopt.rlib build/o/libsysexits.rlib
+	$(RUSTC) $(RUSTFLAGS) --extern getopt=build/o/libgetopt.rlib \
+		--extern sysexits=build/o/libsysexits.rlib \
+		-o $@ src/hru.rs
+
 .PHONY: intcmp
 intcmp: build/bin/intcmp
 build/bin/intcmp: src/intcmp.c build
 	$(CC) $(CFLAGS) -o $@ src/intcmp.c
 
+.PHONY: mm
+mm: build/bin/mm
+build/bin/mm: src/mm.c build
+	$(CC) $(CFLAGS) -o $@ src/mm.c
+
 .PHONY: rpn
 rpn: build/bin/rpn
 build/bin/rpn: src/rpn.rs build build/o/libsysexits.rlib
@@ -102,6 +113,13 @@ strcmp: build/bin/strcmp
 build/bin/strcmp: src/strcmp.c build
 	$(CC) $(CFLAGS) -o $@ src/strcmp.c
 
+.PHONY: swab
+swab: build/bin/swab
+build/bin/swab: src/swab.rs build build/o/libsysexits.rlib
+	$(RUSTC) $(RUSTFLAGS) --extern getopt=build/o/libgetopt.rlib \
+		--extern sysexits=build/o/libsysexits.rlib \
+		-o $@ src/swab.rs
+
 .PHONY: true
 true: build/bin/true
 build/bin/true: src/true.c build

README

@@ -17,6 +17,31 @@ purposes beyond its scope.
 
 See docs/ for more on the specific utilities currently implemented.
 
+Building
+
+The coreutils require a POSIX-compliant environment to compile, including a C
+compiler and preprocessor (cc(1) and cpp(1) by default) with the -idirafter
+flag, a Rust compiler (rustc(1) by default), bindgen(1), and a POSIX-compliant
+make(1) utility.
+
+To build and install:
+
+$ make
+$ make PREFIX="/your/preferred/location" install
+
+To build with a different compiler than the default:
+
+$ make CC=clang
+$ make RUSTC=gccrs
+
+To test the utilities:
+
+$ make test
+
+To remove all untracked files:
+
+$ make clean
+
 Read More
 
 An Introduction to the Unix Shell
@@ -30,3 +55,10 @@ Master Foo Discourses on the Unix-Nature
 
 Shell Programming!
 <https://tldp.org/LDP/abs/html/why-shell.html>
+
+--
+Copyright © 2023–2024 Emma Tebibyte <emma@tebibyte.media>
+Copyright © 2024 DTB <trinity@trinity.moe>
+
+This work is licensed under CC BY-SA 4.0. To view a copy of this license, visit
+<http://creativecommons.org/licenses/by-sa/4.0/>.

docs/dj.1

@@ -1,4 +1,5 @@
 .\" Copyright (c) 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/>.
@@ -44,87 +45,139 @@ dj
 .B output offset
 .R ])
 
-.SH USAGE
+.SH OPTIONS
 
-The
 .B -i
-option takes a path as an argument to open and use in place of standard input.
-The
-.B -o
-option does the same in place of standard output. Dj does not truncate output
-files and instead writes over the bytes in the existing file.
-.PP
-The
+.RS
+Takes a file path as an argument to open and use as an input.
+.RE
+
 .B -b
-option takes a numeric argument as the size in bytes of the input buffer and
-the
-.B -B
-option does the same for the output buffer, the default for both being 1024
-bytes, or one kibibyte (KiB).
-.PP
-The
+.RS
+Takes a numeric argument as the size in bytes of the input buffer, with the
+default being 1024 bytes or one kibibyte (KiB).
+.RE
+
 .B -s
-option takes a numeric argument as the number of bytes to skip into the input
-before starting to read, and the
+.RS
+Takes a numeric argument as the number of bytes to skip into the input
+before starting to read. If the standard input is used, bytes read to this point
+are discarded.
+.RE
+
+.B -o
+.RS
+Takes a file path as an argument to open and use as an output.
+.RE
+
+.B -B
+.RS
+Does the same as
+.B -b
+but for the output buffer.
+.RE
+
 .B -S
-option skips a number of bytes through the output before starting to write from
-the input. If the input is a stream the bytes are read and discarded. If the
-output is a stream, nul characters are printed.
-.PP
-The
+.RS
+Skips a number of bytes through the output before starting to write from
+the input. If the output is a stream, null characters are printed.
+.RE
+
 .B -a
-option takes one argument of one byte in length and pads the input buffer with
-that byte in the event that a read doesn't fill the input buffer, and the
-.B -A
-option takes no arguments and pads with nuls.
-The
+.RS
+Accepts a single literal byte with which input buffer is padded in the event
+of an incomplete read from the input file.
+.RE
+
 .B -c
-option specifies an amount of reads to make, and if 0 (the default) dj will
-continue reading until a partial or empty read.
-.PP
-On a partial or empty read, dj prints a diagnostic message (unless the
-.B -q
-option is specified) and exits (unless the
-.B -n
-option is specified, in which case only two consecutive empty reads will cause
-dj to exit).
-At exit, usage statistics are printed unless the option
-.B -q
-is specified a second time. The
+.RS
+Specifies a number of reads to make. If set to zero (the default), reading will
+continue until a partial or empty read is encountered.
+.RE
+
+.B -A
+.RS
+If the output is a stream, null bytes are printed. This option is equivalent to
+specifying
+.B -a
+with a null byte instead of a character.
+.RE
+
+.B -d
+.RS
+Prints invocation information before program execution as described in the
+DIAGNOSTICS section below. Each invocation increments the debug level of the
+program.
+.RE
+
 .B -H
-option will make these diagnostics human-readable.
+.RS
+Prints diagnostics messages in a human-readable manner as described in the
+DIAGNOSTICS section below.
+.RE
+
+.B -n
+.RS
+Retries failed reads once more before exiting.
+.RE
+
+.B -q
+.RS
+Suppresses error messages which print when a read or write is partial or
+empty. Each invocation decrements the debug level of the program.
+.RE
+
+.SH STANDARD INPUT
+
+The standard input shall be used as an input if no inputs are specified one or
+more of the input files is “-”.
 
 .SH DIAGNOSTICS
 
-The
-.B -d
-option prints all information, user-specified or otherwise, before program
-execution.
-.PP
-When dj exits, by default statistics are printed for input and output to
-standard error in the following format:
-.PP
+On a partial or empty read, a diagnostic message is printed (unless the
+.B -q
+option is specified) and the program exits (unless the
+.B -n
+option is specified.
+
+By default statistics are printed for input and output to the standard error in
+the following format:
+
+.RS
 .R {records read} {ASCII unit separator} {partial records read}
 .R {ASCII record separator} {records written} {ASCII unit separator}
 .R {partial records written} {ASCII group separator} {bytes read}
 .R {ASCII record separator} {bytes written} {ASCII file separator}
-.PP
-If the
+.RE
+
+This format for diagnostic output is designed to be machine-parseable for
+convenience. For a more human-readable format, the
 .B -H
-option is specified dj instead uses this following format:
-.PP
+option may be specified. In this event, the following format is used instead:
+
+.RS
 .R {records read} '+' {partial records read} '>' {records written}
 .R '+' {partial records written} ';' {bytes read} '>' {bytes written}
 .R {ASCII line feed}
-.PP
-The
-.B -q
-option suppresses error messages which print when a read or write is partial or
-empty and when used twice suppresses diagnostic output entirely.
-.PP
-In non-recoverable errors that don't pertain to dj's read-write cycle, a
-diagnostic message is printed and dj exits with the appropriate sysexits(3)
-status.
+.RE
+
+If the
+.B -d
+option is specified, debug output will be printed at the beginning of execution.
+This debug information contains information regarding how the program was
+invoked. The following example is the result of running the program with
+.B -d
+as the only argument:
+
+.RS
+.R argv0=dj
+.R in=<stdin>      ibs=1024        skip=0  align=ff       count=0
+.R out=<stdout>    obs=1024        seek=0  debug= 3       noerror=0
+.RE
+
+In non-recoverable errors that don’t pertain to the read-write cycle, a
+diagnostic message is printed and the program exits with the appropriate
+sysexits.h(3) status.
 
 .SH BUGS
 
@@ -136,25 +189,29 @@ expected (the product of the count multiplied by the input block size). If the
 or
 .B -A
 options are used this could make data written nonsensical.
-.PP
+
 Many lowercase options have capitalized variants and vice-versa which can be
 confusing. Capitalized options tend to affect output or are more intense
 versions of lowercase options.
 
+.SH CAVEATS
+
+Existing files are not truncated on ouput and are instead overwritten.
+
 .SH RATIONALE
 
-Dj was modeled after the dd utility specified in POSIX but adds additional
-features: typical option formatting, allowing seeks to be specified in bytes
+This program was based on the dd(1p) utility as specified in POSIX. While
+character conversion may have been the original intent of dd(1p), it is
+irrelevant to its modern use. Because of this, it eschews character conversion
+and adds typical option formatting, allowing seeks to be specified in bytes
 rather than in blocks, allowing arbitrary bytes as padding, and printing in a
-format that's easy to parse for machines. It also neglects character
-conversion, which may be dd's original intent but is irrelevant to its modern
-use.
+format that’s easy to parse for machines.
 
 .SH COPYRIGHT
 
-Copyright (C) 2023 DTB. License AGPLv3+: GNU AGPL version 3 or later
+Copyright © 2023 DTB. License AGPLv3+: GNU AGPL version 3 or later
 <https://gnu.org/licenses/agpl.html>.
 
 .SH SEE ALSO
 
-dd(1)
+dd(1p)

docs/false.1

@@ -1,5 +1,5 @@
 .\" Copyright (c) 2022, 2024 DTB <trinity@trinity.moe>
-.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
+.\" Copyright (c) 2023–2024 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/>.
@@ -12,14 +12,13 @@ false \(en do nothing, unsuccessfully
 
 .SH DESCRIPTION
 
-False does nothing regardless of operands or standard input.
-False will always return an exit code of 1.
+Do nothing regardless of operands or standard input.
+An exit code of 1 will always be returned.
 
 .SH RATIONALE
 
-False exists for the construction of control flow and loops based on a failure.
-
-False functions as described in POSIX.1-2017.
+In POSIX.1-2017, false(1p) exists for the construction of control flow and loops
+based on a failure. This implementation functions as described in that standard.
 
 .SH AUTHOR
 

docs/fop.1

@@ -0,0 +1,60 @@
+.\" Copyright (c) 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 fop 1
+
+.SH NAME
+
+fop \(en field operator
+
+.SH SYNOPSIS
+
+fop
+.RB ( -d )
+.RB [ delimiter ]
+.RB index 
+.RB program...
+
+.SH DESCRIPTION
+
+Performs operations on specified fields in input data.
+
+.SH OPTIONS
+
+.B -d
+.RS
+Sets a delimiter by which the input data will be split into fields. The default
+is an ASCII record separator (␞).
+.RE
+
+.SH STANDARD INPUT
+
+Data will be read from the standard input.
+
+.SH CAVEATS
+
+Field indices are zero-indexed, which may be unexpected behavior for some users.
+
+.SH RATIONALE
+
+With the assumption that tools will output data separated with ASCII field
+separators, there is 
+
+The idea for this utility originated in the fact that GNU ls(1) utility contains
+a
+.B -h
+option which enables human-readable units in file size outputs. This
+functionality was broken out into hru(1), but there was no easy way to modify
+the field in the ouput of ls(1p) without a new tool.
+
+.SH COPYRIGHT
+
+Copyright © 2024 Emma Tebibyte. License AGPLv3+: GNU AGPL version 3 or later
+<https://gnu.org/licenses/agpl.html>.
+
+.SH SEE ALSO
+
+sed(1p)

docs/hru.1

@@ -0,0 +1,59 @@
+.\" 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 hru 1
+
+.SH NAME
+
+hru \(en human readable units
+
+.SH SYNOPSIS
+
+hru
+
+.SH DESCRIPTION
+
+Convert counts to higher units.
+
+The program will read byte counts in the form of whole numbers from the standard
+input and write to the standard output the same number converted to a higher 
+unit of data as defined by the International System of Units.
+
+The program will convert the byte count to the highest unit possible where the
+value is greater than one.
+
+.SH DIAGNOSTICS
+
+If encountering non-integer characters in the standard input, the program will
+exit with the appropriate error code as defined by sysexits.h(3) and print an
+error message.
+
+.SH RATIONALE
+
+The GNU project’s ls(1) implementation contains a human-readable option (-h)
+that, when specified, makes the tool print size information in a format more
+immediately readable. This functionality is useful not only in the context of
+ls(1) so the decision was made to split it into a new tool. The original
+functionality in GNU’s ls(1) can be emulated with fop(1) combined with this
+program.
+
+.SH STANDARDS
+
+The standard unit prefixes as specified by the Bureau International des Poids
+et Mesures (BIPM) in the ninth edition of The International System of Units
+(SI) are utilized for the ouput of conversions.
+
+.SH AUTHOR
+
+Written by Emma Tebibyte <emma@tebibyte.media>.
+
+.SH COPYRIGHT
+
+Copyright (c) 2024 Emma Tebibyte. License AGPLv3+: GNU AGPL version 3 or later
+<https://gnu.org/licenses/agpl.html>.
+
+.SH SEE ALSO
+
+GNU ls(1), The International System of Units (SI) 9th Edition

docs/intcmp.1

@@ -1,5 +1,5 @@
 .\" Copyright (c) 2023–2024 DTB <trinity@trinity.moe>
-.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
+.\" Copyright (c) 2023–2024 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/>.
@@ -13,45 +13,59 @@ intcmp \(en compare integers
 .SH SYNOPSIS
 
 intcmp
-.RB ( -eghl )
+.RB ( -egl )
 .RB [ integer ]
 .RB [ integer... ]
 
 .SH DESCRIPTION
 
-Intcmp compares integers.
+Compare integers to each other.
 
 .SH USAGE
 
-The -e option permits given integers to be equal to each other. If combined
-with -g or -l, only adjacent integers in the argument sequence can be equal.
-.PP
-The -g option permits a given integer to be greater than the following integer.
-.PP
-The -l option permits a given integer to be less than the following integer.
-.PP
+.B -e
+.RS
+Permits given integers to be equal to each other.
+.RE
+
+.B -g
+.RS
+Permits a given integer to be greater than the following integer.
+.RE
+
+.B -l
+.RS
+Permits a given integer to be less than the following integer.
+.RE
+
+.SH EXAMPLES
+
 It may help to think of the -e, -g, and -l options as equivalent to the
 infix algebraic “=”, “>”, and “<” operators respectively, with each option
-putting its symbol between every given integer. For example,
+putting its symbol between every given integer. The following example is
+equivalent to evaluating “1 < 2 < 3”:
+
+.RS
 .R intcmp -l 1 2 3
-is equivalent to evaluating "1 < 2 < 3".
+.RE
 
 .SH DIAGNOSTICS
 
-Intcmp exits 0 for a valid expression and 1 for an invalid expression.
-.PP
-Intcmp prints a debug message and exits with the appropriate sysexits(3) error
-code in the event of an error.
+The program will exit with a status code of 0 for a valid expression and with a
+code of 1 for an invalid expression.
+
+In the event of an error, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
 
 .SH BUGS
 
 There are multiple ways to express compound comparisons; “less than or equal
 to” can be -le or -el, for example.
-.PP
+
 The inequality comparison is -gl or -lg for “less than or greater than”; this
 is elegant but unintuitive.
-.PP
--egl, "equal to or less than or greater than", exits 0 no matter what for valid
+
+-egl, “equal to or less than or greater than”, exits 0 no matter what for valid
 program usage and may be abused to function as an integer validator.
 Use str(1) instead.
 
@@ -61,7 +75,7 @@ The traditional tool for integer comparisons in POSIX and other Unix shells has
 been test(1). This tool also handles string comparisons and file scrutiny.
 These parts of its functionality have been broken out into multiple utilities.
 
-Strcmp’s functionality may be performed on a POSIX-compliant system with
+This program’s functionality may be performed on a POSIX-compliant system with
 test(1p).
 
 .SH AUTHOR

docs/mm.1

@@ -0,0 +1,88 @@
+.\" Copyright (c) 2024 DTB <trinity@trinity.moe>
+.\"
+.\" 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
+
+.SH NAME
+
+mm \(en middleman
+
+.SH SYNOPSIS
+
+mm
+.RB ( -aenu )
+.RB ( -i
+.RB [ input ])
+.RB ( -o
+.RB [ output ])
+
+.SH DESCRIPTION
+
+Catenate input files and write them to the start of each output file or stream.
+
+.SH OPTIONS
+
+.B -a
+.RS
+Opens subsequent outputs for appending rather than updating.
+.RE
+
+.B -e
+.RS
+Use the standard error as an output.
+.RE
+
+.B -i
+.RS
+Opens a path as an input. Without any inputs specified mm will use the
+standard input. The standard input shall be used as an input if one or more of
+the input files is “-”.
+.RE
+
+.B -o
+.RS
+Opens a path as an output. Without any outputs specified mm will use the
+standard output. The standard output shall be used as an output if one or more
+of the output files is “-”.
+
+.RE
+
+.B -u
+.RS
+Ensures neither input or output will be buffered.
+.RE
+
+.B -n
+.RS
+Causes SIGINT signals to be ignored.
+.RE
+
+.SH DIAGNOSTICS
+
+If an output can no longer be written mm prints a diagnostic message, ceases
+writing to that particular output, and if there are more outputs specified,
+continues, eventually exiting unsuccessfully.
+
+When an error is encountered, diagnostic message is printed and the program
+exits with the appropriate sysexits.h(3) status.
+
+.SH CAVEATS
+
+Existing files are not truncated on ouput and are instead overwritten.
+
+.SH RATIONALE
+
+The cat(1p) and tee(1p) programs specified in POSIX together provide similar
+functionality. The separation of the two sets of functionality into separate
+APIs seemed unncessary.
+
+.SH COPYRIGHT
+
+Copyright (c) 2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
+<https://gnu.org/licenses/agpl.html>.
+
+.SH SEE ALSO
+
+cat(1p), dd(1), dj(1), tee(1p)

docs/npc.1

@@ -1,5 +1,5 @@
 .\" Copyright (c) 2023–2024 DTB <trinity@trinity.moe>
-.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
+.\" Copyright (c) 2023–2024 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/>.
@@ -13,43 +13,50 @@ npc \(en show non-printing characters
 .SH SYNOPSIS
 
 npc
-.RB ( -eht )
+.RB ( -et )
 
 .SH DESCRIPTION
 
-Npc reads from standard input and writes to standard output, replacing non-
-printing characters with printable equivalents. Control characters print as a
-carat ('^') followed by the character '@' through '_' corresponding to the
-character replaced (e.g. control-X becomes "^X"). The delete character (0x7F)
-becomes "^?". Characters with the high bit set (>127) are printed as "M-"
+Print normally non-printing characters.
+
+The program reads from standard input and writes to standard output, replacing
+non-printing characters with printable equivalents. Control characters print as
+a carat ('^') followed by the character '@' through '_' corresponding to the
+character replaced (e.g. control-X becomes '^X'). The delete character (0x7F)
+becomes '^?'. Characters with the high bit set (>127) are printed as 'M-'
 followed by the graphical representation for the same character without the
 high bit set.
-.PP
-The
+
+.SH USAGE
+
 .B -e
-option prints a currency sign ('$') before each line ending.
-.PP
-The
+.RS
+Prints a currency sign ('$') before each line ending.
+.RE
+
 .B -t
-option prints tab characters as "^I" rather than a literal horizontal tab.
+.RS
+Prints tab characters as '^I' rather than a literal horizontal tab.
+.RE
 
 .SH DIAGNOSTICS
 
-Npc prints a debug message and exits with the appropriate sysexits(3) error
-code in the event of an error, otherwise it exits successfully.
+In the event of an error, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
 
 .SH BUGS
 
-Npc operates in single-byte chunks regardless of intended encoding.
+The program operates in single-byte chunks regardless of intended encoding.
 
 .SH RATIONALE
 
 POSIX currently lacks a way to display non-printing characters in the terminal
-using a standard tool. A popular extension to cat(1p), the -v option, is the
-bandage solution GNU and other software suites use.
+using a standard tool. A popular extension to cat(1p), the
+.B -v
+option, is the bandage solution GNU and other software suites use.
 
-This functionality should be a separate tool because its usefulness extends
-beyond that of cat(1p).
+This functionality is a separate tool because its usefulness extends beyond that
+of cat(1p).
 
 .SH AUTHOR
 

docs/rpn.1

@@ -17,10 +17,13 @@ rpn
 
 .SH DESCRIPTION
 
-Rpn evaluates reverse polish notation expressions either read from the standard
-input or parsed from provided arguments. See the STANDARD INPUT section.
+Evaluate reverse polish notation.
 
-Upon evaluation, rpn will print the resulting number on the stack to the
+The program evaluates reverse polish notation expressions either read from the
+standard input or parsed from provided arguments. See the STANDARD INPUT
+section.
+
+Upon evaluation, the program will print the resulting number on the stack to the
 standard output. Any further specified numbers will be placed at the end of the
 stack.
 
@@ -28,14 +31,16 @@ For information on for reverse polish notation syntax, see rpn(7).
 
 .SH STANDARD INPUT
 
-If arguments are passed to rpn, it interprets them as an expression to be
-evaluated. Otherwise, it reads whitespace-delimited numbers and operations from
-the standard input.
+If arguments are passed , they are interpreted as an expression to be evaluated.
+Otherwise, it reads whitespace-delimited numbers and operations from the
+standard input.
 
 .SH DIAGNOSTICS
 
-If encountering a syntax error, rpn will exit with the appropriate error code
-as defined by sysexits.h(3) and print an error message.
+In the event of a syntax error, the program will print an
+
+In the event of an error, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
 
 .SH CAVEATS
 
@@ -44,7 +49,7 @@ with the IEEE Standard for Floating Point Arithmetic (IEEE 754), floating-point
 arithmetic has rounding errors. This is somewhat curbed by using the
 machine epsilon as provided by the Rust standard library to which to round
 numbers. Because of this, variation is expected in the number of decimal places 
-rpn can handle based on the platform and hardware of any given machine.
+the program can handle based on the platform and hardware of any given machine.
 
 .SH RATIONALE
 

docs/scrut.1

@@ -0,0 +1,124 @@
+.\" Copyright (c) 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 scrut 1
+
+.SH NAME
+
+scrut \(en scrutinize file properties
+
+.SH SYNOPSIS
+
+scrut
+.RB ( -bcdefgkprsuwxLS )
+.RB [ file... ]
+
+.SH DESCRIPTION
+
+Determine if files comply with requirements.
+
+.SH OPTIONS
+
+.B -L
+.RS
+Requires the given files to exist and be symbolic links.
+.RE
+
+.B -S
+.RS
+Requires the given files to exist and be sockets.
+.RE
+
+.B -b
+.RS
+Requires the given files to exist and be block special files.
+.RE
+
+.B -c
+.RS
+Requires the given files to exist and be character special files.
+.RE
+
+.B -d
+.RS
+Requires the given files to exist and be directories.
+.RE
+
+.B -e
+.RS
+Requires the given files to exist, and is redundant to any other option.
+.RE
+
+.B -e
+.RS
+Requires the given files to exist and be regular files.
+.RE
+
+.B -g
+.RS
+Requires the given files to exist and have their set group ID flags set.
+.RE
+
+.B -k
+.RS
+Requires the given files to exist and have their sticky bit set.
+.RE
+
+.B -p
+.RS
+Requires the given files to exist and be named pipes.
+.RE
+
+.B -r
+.RS
+Requires the given files to exist and be readable.
+.RE
+
+.B -u
+.RS
+Requires the given files to exist and have their set user ID flags set.
+.RE
+
+.B -w
+.RS
+Requires the given files to exist and be writable.
+.RE
+
+.B -x
+.RS
+Requires the given files to exist and be executable.
+.RE
+
+.SH EXIT STATUS
+
+If the given files comply with the specified requirements, the program will exit
+successfully. If not, it exits unsuccessfully.
+
+When invoked incorrectly, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
+
+.SH STANDARDS
+
+The test(1p) utility contains functionality that was broken out into separate
+programs. Thus, the scope of this program is narrower than it. Notably, the
+.B -h
+option is now invalid and therefore shows usage information instead of being an
+alias to the modern
+.B -L
+option.
+
+.SH AUTHOR
+
+Written by DTB <trinity@trinity.moe>.
+
+.SH COPYRIGHT
+
+Copyright © 2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
+<https://gnu.org/licenses/agpl.html>.
+
+.SH SEE ALSO
+
+access(3p), lstat(3p), test(1p)

docs/str.1

@@ -1,5 +1,5 @@
 .\" Copyright (c) 2023–2024 DTB <trinity@trinity.moe>
-.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
+.\" Copyright (c) 2023–2024 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/>.
@@ -18,30 +18,27 @@ str
 
 .SH DESCRIPTION
 
-Str tests each character in an arbitrary quantity of string arguments against
-the function of the same name within ctype(3).
+Test string arguments.
+
+The tests in this program are equivalent to the functions with the same names in
+ctype.h(0p) and are the methods by which string arguments are tested.
 
 .SH DIAGNOSTICS
 
-Str exits successfully if all tests pass and unsuccessfully if a test failed.
-.PP
-Str will exit unsuccessfully if a string is empty, as none of its contents
-passed the test.
-.PP
-Str will print a message to standard error and exit unsuccessfully if used
-improperly.
+If all tests pass, the program will exit with an exit code of 0. If any of the
+tests fail, the program will exit unsuccessfully with an error code of 1.
 
-.SH DEPRECATED FEATURES
+An empty string will cause an unsuccessful exit as none of its contents pass any
+tests.
 
-Str used to have an "isvalue" type as an extension to ctype(3). This was
-removed in favor of using strcmp(1) to compare strings against the empty string
-('').
+When invoked incorrectly, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
 
 .SH BUGS
 
-There's no way of knowing which argument failed the test without re-testing
+There’s no way of knowing which argument failed the test without re-testing
 arguments individually.
-.PP
+
 If a character in a string isn't valid ASCII str will exit unsuccessfully.
 
 .SH AUTHOR

docs/strcmp.1

@@ -1,5 +1,5 @@
 .\" Copyright (c) 2023–2024 DTB <trinity@trinity.moe>
-.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
+.\" Copyright (c) 2023–2024 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/>.
@@ -18,26 +18,27 @@ strcmp
 
 .SH DESCRIPTION
 
-Strcmp checks whether the given strings are the same.
-Strcmp exits successfully if the strings are identical. Otherwise, strcmp exits
-with the value 1 if an earlier string has a greater byte value than a later
-string (e.g.
+Check whether string arguments are the same.
+
+.SH DIAGNOSTICS
+
+The program will exit successfully if the strings are identical. Otherwise, it
+exits with the value 1 if an earlier string has a greater byte value than a
+later string (e.g.
 .R strcmp b a
 )
 and 255 if an earlier string has a lesser byte value (e.g.
 .R strcmp a b
 ).
 
-.SH DIAGNOSTICS
-
-Strcmp will print an error message and exit unsuccessfully with a status
-described in sysexits(3) if used incorrectly (given less than two operands).
+When invoked incorrectly, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
 
 .SH UNICODE
 
-Strcmp will exit unsuccessfully if the given strings are not identical;
-Unicode strings may need to be normalized if the intent is to check visual
-similarity and not byte similarity.
+The program will exit unsuccessfully if the given strings are not identical;
+therefore, Unicode strings may need to be normalized if the intent is to check
+visual similarity and not byte similarity.
 
 .SH RATIONALE
 
@@ -45,7 +46,7 @@ The traditional tool for string comparisons in POSIX and other Unix shells has
 been test(1). This tool also handles integer comparisons and file scrutiny.
 These parts of its functionality have been broken out into multiple utilities.
 
-Strcmp’s functionality may be performed on a POSIX-compliant system with
+This program’s functionality may be performed on a POSIX-compliant system with
 test(1p).
 
 .SH AUTHOR

docs/swab.1

@@ -0,0 +1,77 @@
+.\" Copyright (c) 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 swab 1
+
+.SH NAME
+
+swab \(en swap bytes
+
+.SH SYNOPSIS
+
+swab
+.RB ( -f )
+.RB ( -w
+.R [
+.B word size
+.R ])
+
+.SH USAGE
+
+Swap the latter and former halves of a block of bytes.
+
+.SH OPTIONS
+
+.B -f
+.RS
+Ignore system call interruptions.
+.RE
+
+.B -w
+.RS
+Configures the word size; that is, the size in bytes of the block size
+on which to operate. By default the word size is 2. The word size must be
+cleanly divisible by 2, otherwise the block of bytes being processed can't be
+halved.
+.RE
+
+.SH EXAMPLES
+
+The following sh(1p) line:
+
+.RS
+.R printf 'hello world!\n' | swab
+.RE
+
+Produces the following output:
+
+.RS
+.R ehll oowlr!d
+.RE
+
+.SH DIAGNOSTICS
+
+In the event of an error, a debug message will be printed and the program will
+exit with the appropriate sysexits.h(3) error code.
+
+.SH RATIONALE
+
+This program was modeled and named after the
+.R conv=swab
+functionality specified in the dd(1p) utility. It additionally allows the word
+size to be configured.
+
+This functionality is useful for fixing the endianness of binary files produced
+on other machines.
+
+.SH COPYRIGHT
+
+Copyright (c) 2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
+<https://gnu.org/licenses/agpl.html>.
+
+.SH SEE ALSO
+
+dd(1p)

docs/true.1

@@ -1,5 +1,5 @@
 .\" Copyright (c) 2022, 2024 DTB <trinity@trinity.moe>
-.\" Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
+.\" Copyright (c) 2023–2024 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/>.
@@ -12,14 +12,13 @@ true \(en do nothing, successfully
 
 .SH DESCRIPTION
 
-True does nothing regardless of operands or standard input.
-True will always return an exit code of 0.
+Do nothing regardless of operands or standard input.
+An exit code of 0 will always be returned.
 
 .SH RATIONALE
 
-True exists for the construction of control flow and loops based on a success.
-
-True functions as described in POSIX.1-2017.
+In POSIX.1-2017, true(1p) exists for the construction of control flow and loops
+based on a success. This implementation functions as described in that standard.
 
 .SH AUTHOR
 

src/dj.c

@@ -203,28 +203,28 @@ Io_fdseek(struct Io *io){
 	
 	if(!fdisstd(io->fd) && lseek(io->fd, io->seek, SEEK_SET) != -1)
 		return -1;
-	else if(io->fl == write_flags){
-		memset(io->buf, '\0', io->bs);
-		/* This is a dirty trick; rather than testing conditions and operating
-		 * likewise, because the parameters to read or write are going to be
-		 * the same either way, just use a function pointer to keep track of
-		 * the intended operation. */
-		op = (int (*)(int, void *, size_t))&write;
-		/* Function pointer casts are risky; this works because the difference
-		 * is in the second parameter and only that write(2) makes the buffer
-		 * const whereas read(2) does not. To avoid even the slightest
-		 * undefined behavior comment out the cast, just be ready for a
-		 * -Wincompatible-function-pointer-types if your compiler notices it.
-		 */
-	}else
-		op = &read;
 
-	/* We're going to cheat and use bufuse as the retval for write(2), which is
-	 * fine because it'll be zeroed as this function returns anyway. */
-	do{	if(	(io->bufuse = (*op)(io->fd, io->buf, MIN(io->bs, io->seek))) == 0)
-			/* second chance */
-			io->bufuse = (*op)(io->fd, io->buf, MIN(io->bs, io->seek));
-	}while((io->seek -= io->bufuse) > 0 && io->bufuse != 0);
+	/* repeated code to get the condition out of the loop */
+	if(io->fl == write_flags){
+		memset(io->buf, '\0', io->bs);
+		/* We're going to cheat and use bufuse as the retval for write(2),
+		 * which is fine because it'll be zeroed as this function returns
+		 * anyway. */
+		do{
+			if((io->bufuse = write(io->fd, io->buf, MIN(io->bs, io->seek)))
+					== 0)
+				/* second chance */
+				io->bufuse = write(io->fd, io->buf, MIN(io->bs, io->seek));
+		}while((io->seek -= io->bufuse) > 0 && io->bufuse != 0);
+	}else if(io->fl == read_flags){
+		do{
+			if((io->bufuse = read(io->fd, io->buf, MIN(io->bs, io->seek)))
+					== 0)
+				/* second chance */
+				io->bufuse = read(io->fd, io->buf, MIN(io->bs, io->seek));
+		}while((io->seek -= io->bufuse) > 0 && io->bufuse != 0);
+	}else
+		return EX_SOFTWARE;
 
 	io->bufuse = 0;
 

src/fop.rs

@@ -18,7 +18,7 @@
 
 use std::{
 	env::args,
-	io::{ Read, stdin, Write },
+	io::{ Read, stdin, stdout, Write },
 	process::{ Command, exit, Stdio },
 };
 
@@ -26,7 +26,7 @@ extern crate sysexits;
 extern crate getopt;
 
 use getopt::{ Opt, Parser };
-use sysexits::{ EX_DATAERR, EX_USAGE };
+use sysexits::{ EX_DATAERR, EX_IOERR, EX_UNAVAILABLE, EX_USAGE };
 
 fn main() {
 	let argv = args().collect::<Vec<String>>();
@@ -54,43 +54,65 @@ fn main() {
 		exit(EX_USAGE);
 	});
 
-	let index = argv[index_arg].parse::<usize>().unwrap_or_else(|_| {
-		eprintln!("{}: {}: Not an integer.", argv[0], argv[1]);
+	let index = argv[index_arg].parse::<usize>().unwrap_or_else(|e| {
+		eprintln!("{}: {}: {}.", argv[0], argv[1], e);
 		exit(EX_DATAERR);
 	});
 
 	let mut buf = String::new();
-	stdin().read_to_string(&mut buf).unwrap();
+	let _ = stdin().read_to_string(&mut buf);
 	let mut fields = buf.split(d).collect::<Vec<&str>>();
 
-	let opts = argv.iter().clone().skip(command_arg + 1).collect::<Vec<&String>>();
+	let opts = argv
+		.iter()
+		.clone()
+		.skip(command_arg + 1)
+		.collect::<Vec<&String>>();
 
 	let mut spawned = Command::new(argv.get(command_arg).unwrap())
 		.args(opts)
 		.stdin(Stdio::piped())
 		.stdout(Stdio::piped())
 		.spawn()
-		.unwrap();
+		.unwrap_or_else( |e| {
+			eprintln!("{}: {}: {}.", argv[0], argv[command_arg], e);
+			exit(EX_UNAVAILABLE);
+		});
 
 	let field = fields.get(index).unwrap_or_else(|| {
 		eprintln!(
 			"{}: {}: No such index in input.",
 			argv[0],
-			index.to_string()
+			index.to_string(),
 		);
 		exit(EX_DATAERR);
 	});
 
 	if let Some(mut child_stdin) = spawned.stdin.take() {
-		child_stdin.write_all(field.as_bytes()).unwrap();
+		let _ = child_stdin.write_all(field.as_bytes());
 		drop(child_stdin);
 	}
 
-	let output = spawned.wait_with_output().unwrap();
+	let output = spawned.wait_with_output().unwrap_or_else(|e| {
+		eprintln!("{}: {}: {}.", argv[0], argv[command_arg], e);
+		exit(EX_IOERR);
+	});
 
-	let new_field = String::from_utf8(output.stdout).unwrap();
+	let mut replace = output.stdout.clone();
+
+	if replace.pop() != Some(b'\n') { replace = output.stdout; }
+
+	let new_field = String::from_utf8(replace).unwrap_or_else(|e| {
+		eprintln!("{}: {}: {}.", argv[0], argv[command_arg], e);
+		exit(EX_IOERR);
+	});
 
 	fields[index] = &new_field;
 
-	print!("{}", fields.join(&d.to_string()));
+	stdout().write_all(
+		fields.join(&d.to_string()).as_bytes()
+	).unwrap_or_else(|e|{
+		eprintln!("{}: {}.", argv[0], e);
+		exit(EX_IOERR);
+	});
 }

src/hru.rs

@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2023–2024 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::{
+	cmp::Ordering,
+	env::args,
+	io::{ stdin, stdout, Write },
+	process::{ ExitCode, exit },
+};
+
+extern crate sysexits;
+
+use sysexits::{ EX_DATAERR, EX_IOERR, EX_SOFTWARE };
+
+const LIST: [(u32, &str); 10] = [
+	(3, "k"),
+	(6, "M"),
+	(9, "G"),
+	(12, "T"),
+	(15, "P"),
+	(18, "E"),
+	(21, "Z"),
+	(24, "Y"),
+	(27, "R"),
+	(30, "Q")
+];
+
+fn convert(input: u128) -> Result<(f64, (u32, &'static str)), String> {
+
+	let mut out = (input as f64, (0_u32, ""));
+	if input < 1000 { return Ok(out); }
+
+	for (n, p) in LIST {
+		let c = match 10_u128.checked_pow(n) {
+			Some(c) => c,
+			None => {
+				return Err(format!("10^{}: Integer overflow.", n.to_string()));
+			},
+		};
+
+		match c.cmp(&input) {
+			Ordering::Less => {
+				out = (input as f64 / c as f64, (n, p));
+			},
+			Ordering::Equal => {
+				return Ok((input as f64 / c as f64, (n, p)));
+			},
+			Ordering::Greater => {},
+		};
+	}
+
+	Ok(out)
+}
+
+fn main() -> ExitCode {
+	let argv = args().collect::<Vec<String>>();
+	let mut buf = String::new();
+	while let Ok(_) = stdin().read_line(&mut buf) {
+		if buf.is_empty() { return ExitCode::SUCCESS; }
+
+		let n: u128 = match buf.trim().parse() {
+			Ok(f) => {
+				buf.clear();
+				f
+			},
+			Err(err) => {
+				eprintln!("{}: {}.", argv[0], err);
+				return ExitCode::from(EX_DATAERR as u8);
+			},
+		};
+
+		let (number, prefix) = match convert(n) {
+			Ok(x) => x,
+			Err(err) => {
+				eprintln!("{}: {}.", argv[0], err);
+				return ExitCode::from(EX_SOFTWARE as u8);
+			},
+		};
+
+		let si_prefix = format!("{}B", prefix.1);
+
+		let out = ((number * 10.0).round() / 10.0).to_string();
+
+		stdout().write_all(format!("{} {}\n", out, si_prefix).as_bytes())
+			.unwrap_or_else(|e| {
+				eprintln!("{}: {}.", argv[0], e);
+				exit(EX_IOERR);
+			});
+	}
+
+	ExitCode::SUCCESS
+}

src/mm.c

@@ -0,0 +1,224 @@
+/*
+ * 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
+
+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:
+				fprintf(stderr, "Usage: %s (-aenu) (-i [input])..."
+					" (-o [output])...\n", argv[0]);
+				retval = EX_USAGE;
+				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/rpn.rs

@@ -165,7 +165,7 @@ fn eval(
 						Subtract => stack.push_back(y - x),
 						Multiply => stack.push_back(y * x),
 						Divide => stack.push_back(y / x),
-						Power => stack.push_back(x.powf(y)),
+						Power => stack.push_back(y.powf(x)),
 						Floor => stack.push_back((y / x).floor()),
 						Modulo => stack.push_back(y % x),
 						_ => {},

src/scrut.c

@@ -18,7 +18,7 @@
 
 #include <stdio.h> /* fprintf(3), stderr, NULL */
 #include <stdlib.h> /* EXIT_FAILURE */
-#include <string.h> /* strchr(3) */
+#include <string.h> /* memset(3), strchr(3) */
 #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,
@@ -33,17 +33,24 @@ int main(int argc, char *argv[]){
 	struct stat buf;
 	int c;
 	size_t i;
+	char *p;
 
 	if(argc < 2)
 		goto usage;
 
-	i = 0;
+	memset(ops, '\0', sizeof ops);
 	while((c = getopt(argc, argv, args)) != -1)
-		if(strchr(args, c) == NULL)
+		if((p = strchr(args, c)) == NULL)
 			goto usage;
 		else
-			ops[i++] = c;
-	ops[i] = '\0';
+			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;

src/swab.rs

@@ -0,0 +1,90 @@
+/*
+ * 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,
+	io::{ stdin, stdout, Error, ErrorKind, Read, Write },
+	process::ExitCode,
+	vec::Vec
+};
+
+extern crate getopt;
+use getopt::{ Opt, Parser };
+
+extern crate sysexits;
+use sysexits::{ EX_OK, EX_OSERR, EX_USAGE };
+
+fn oserr(s: &str, e: Error) -> ExitCode {
+	eprintln!("{}: {}", s, e);
+	ExitCode::from(EX_OSERR as u8)
+}
+
+fn usage(s: &str) -> ExitCode {
+	eprintln!("Usage: {} (-f) (-w [wordsize])", s);
+	ExitCode::from(EX_USAGE as u8)
+}
+
+fn main() -> ExitCode {
+	let argv = args().collect::<Vec<String>>();
+	let mut buf: Vec<u8> = Vec::new();
+	let mut input = stdin();
+	let mut output = stdout().lock();
+
+	let mut opts = Parser::new(&argv, "fw:");
+	let mut force = false;
+	let mut wordsize: usize = 2;
+
+	loop {
+		match opts.next() {
+			None => break,
+			Some(opt) =>
+				match opt {
+					Ok(Opt('f', None)) => force = true,
+					Ok(Opt('w', Some(arg))) => {
+						match arg.parse::<usize>() {
+							Ok(w) if w % 2 == 0 => { wordsize = w; () },
+							_ => { return usage(&argv[0]); },
+						}
+					},
+					_ => { return usage(&argv[0]); }
+				}
+		}
+	}
+
+	buf.resize(wordsize, 0);
+
+	loop {
+		match input.read(&mut buf) {
+			Ok(0) => break ExitCode::from(EX_OK as u8),
+			Ok(v) if v == wordsize => {
+				let (left, right) = buf.split_at(v/2);
+				if let Err(e) = output.write(&right)
+						.and_then(|_| output.write(&left)) {
+					break oserr(&argv[0], e)
+				}
+			},
+			Ok(v) => {
+				if let Err(e) = output.write(&buf[..v]) {
+					break oserr(&argv[0], e)
+				}
+			},
+			Err(e) if e.kind() == ErrorKind::Interrupted && force => continue,
+			Err(e) => break oserr(&argv[0], e)
+		}
+	}
+}

tests/cc-compat.sh

@@ -1,40 +0,0 @@
-#!/bin/sh
-
-# Copyright (c) 2023–2024 Emma Tebibyte <emma@tebibyte.media>
-# SPDX-License-Identifier: FSFAP
-#
-# Copying and distribution of this file, with or without modification, are
-# permitted in any medium without royalty provided the copyright notice and this
-# notice are preserved.  This file is offered as-is, without any warranty.
-
-set -e
-
-if ! ls Makefile >/dev/null 2>&1
-then
-	printf '%s: Run this script in the root of the project.\n' "$0" 1>&2 
-	exit 64 # sysexits.h(3) EX_USAGE
-fi
-
-make clean
-./configure clean
-./configure
-
-for CC in cc \
-	clang \
-	gcc \
-	'zig cc'
-do
-	export CC
-
-	command -v "$(printf '%s\n' "$CC" | cut -d ' ' -f1)" >/dev/null 2>&1 \
-		|| continue
-
-	printf '%s: %s: Testing build.\n' "$0" "$CC"
-
-	make CC="$CC" && printf '%s: Build successful.\n' "$0"
-
-	ls -lA build/bin
-
-	make clean
-	printf '\n'
-done