Merge branch 'makefile-improved'

Makefile

@@ -16,9 +16,12 @@
 DESTDIR ?= dist
 PREFIX ?= /usr/local
 
-MANDIR != [ $(PREFIX) = / ] && printf '/usr/share/man\n' \
+# normalized prefix
+PREFIX_N != (test -d $(PREFIX) && [ '-' != $(PREFIX) ] \
+	&& CDPATH= cd -P -- $(PREFIX) && pwd -P)
+MANDIR != [ $(PREFIX_N) = / ] && printf '/usr/share/man\n' \
 	|| printf '/share/man\n'
-SYSEXITS != printf '\043include <sysexits.h>\n' | cpp -M - | sed 's/ /\n/g' \
+SYSEXITS != printf '\043include <sysexits.h>\n' | cpp -M - | tr ' ' '\n' \
 	| sed -n 's/sysexits\.h//p' || printf 'include\n'
 
 CC ?= cc
@@ -29,7 +32,7 @@ RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
 CFLAGS += -I$(SYSEXITS)
 
 .PHONY: all
-all: docs dj false fop hru intcmp mm npc rpn scrut str strcmp swab true
+all: dj false 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
@@ -40,8 +43,8 @@ build:
 clean:
 	rm -rf build dist
 
-dist: all
-	mkdir -p $(DESTDIR)/$(PREFIX)/bin $(DESTDIR)/$(PREFIX)/share/man/man1
+dist: all docs
+	mkdir -p $(DESTDIR)/$(PREFIX)/bin $(DESTDIR)/$(PREFIX)/$(MANDIR)/man1
 	cp build/bin/* $(DESTDIR)/$(PREFIX)/bin
 	cp build/docs/*.1 $(DESTDIR)/$(PREFIX)/$(MANDIR)/man1
 
@@ -76,13 +79,14 @@ build/o/libstrerror.rlib: build src/libstrerror.rs
 	$(RUSTC) $(RUSTFLAGS) --crate-type=lib -o $@ \
 		src/libstrerror.rs
 
-# bandage solution until bindgen(1) gets stdin support
-build/o/libsysexits.rlib: build $(SYSEXITS)sysexits.h
-	printf '\043define EXIT_FAILURE 1\n' | cat - $(SYSEXITS)sysexits.h \
-		> build/include/sysexits.h 
+build/o/libsysexits.rlib: build/include/sysexits.h
 	bindgen --default-macro-constant-type signed --use-core --formatter=none \
 		build/include/sysexits.h | $(RUSTC) $(RUSTFLAGS) --crate-type lib -o $@ -
 
+# bandage solution until bindgen(1) gets stdin support
+build/include/sysexits.h: build $(SYSEXITS)sysexits.h
+	printf '\043define EXIT_FAILURE 1\n' | cat - $(SYSEXITS)sysexits.h > $@
+
 .PHONY: dj
 dj: build/bin/dj
 build/bin/dj: src/dj.c build

docs/dj.1

@@ -4,32 +4,24 @@
 .\" 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 DJ 1 2024-06-17 "Harakit X.X.X"
+.TH DJ 1 2024-06-29 "Harakit X.X.X"
 .SH NAME
 dj \(en disk jockey
 .\"
 .SH SYNOPSIS
 
 dj
-.RB ( -AdHnq )
-.RB ( -a
-.RB [ byte ])
-.RB ( -c
-.RB [ count ])
+.RB [ -Hn ]
+.RB [ -a\ byte ]
+.RB [ -c\ count ]
 
-.RB ( -i
-[\fBinput file\fP])
-.RB ( -b
-[\fBinput block size\fP])
-.RB ( -s
-[\fBinput offset\fP])
+.RB [ -i\ file ]
+.RB [ -b\ block_size ]
+.RB [ -s\ offset ]
 
-.RB ( -o
-[\fBoutput file\fP])
-.RB ( -B
-[\fBoutput block size\fP])
-.RB ( -S
-[\fBoutput offset\fP])
+.RB [ -o\ file ]
+.RB [ -B\ block_size ]
+.RB [ -S\ offset ]
 .\"
 .SH DESCRIPTION
 
@@ -47,63 +39,51 @@ immediately subsequent to the specified byte.
 .\"
 .SH OPTIONS
 
-.IP \fB-i\fP
+.IP \fB-i\fP\ \fIfile\fP
 Takes a file path as an argument and opens it for use as an input.
-.IP \fB-b\fP
+.IP \fB-b\fP\ \fIblock_size\fP
 Takes a numeric argument as the size in bytes of the input buffer, the default
 being 1024.
 .IP \fB-s\fP
-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.
+Takes a numeric argument as the index of the byte at which reading will
+commence; \(lqskips\(rq that number of bytes. If the standard input is used,
+bytes read to this point are discarded.
 .IP \fB-o\fP
 Takes a file path as an argument and opens it for use as an output.
-.IP \fB-B\fP
+.IP \fB-B\fP\ \fIblock_size\fP
 Does the same as
 .B -b
 but for the output buffer.
 .IP \fB-S\fP
-Seeks a number of bytes through the output before starting to write from
-the input. If the output is a stream, null characters are printed.
+Takes a numeric argument as the index of the byte at which writing will
+commence; \(lqseeks\(rq that number of bytes. If the standard output is used,
+null characters are printed.
 .IP \fB-a\fP
 Accepts a single literal byte with which the input buffer is padded in the event
-of an incomplete read from the input file.
-.IP \fB-A\fP
-Specifying this option pads the input buffer with null bytes in the event of an
-incomplete read. This is equivalent to specifying
-.B -a
-with a null byte instead of a character.
+of an incomplete read from the input file. If the option argument is empty, the
+null byte is used.
 .IP \fB-c\fP
 Specifies a number of reads to make. The default is 0, in which case the
 input is read until a partial or empty read is made.
-.IP \fB-d\fP
-Prints invocation information before program execution as described in the
-DIAGNOSTICS section. Each invocation increments the debug level of the
-program.
 .IP \fB-H\fP
-Prints diagnostics messages in a human-readable manner as described in the
+Prints diagnostic messages in a human-readable manner as described in the
 DIAGNOSTICS section.
 .IP \fB-n\fP
 Retries failed reads once before exiting.
-.IP \fB-q\fP
-Suppresses error messages which print when a read or write is partial or
-empty. Each invocation decrements the debug level of the program.
 .\"
 .SH STANDARD INPUT
 
 The standard input shall be used as an input if no inputs are specified or if
-one or more of the input files is \(lq-\(rq.
+input file is \(lq-\(rq.
 .\"
 .SH STANDARD OUTPUT
 The standard output shall be used as an output if no inputs are specified or if
-one or more of the input files is \(lq-\(rq.
+the output file is \(lq-\(rq.
 .\"
 .SH DIAGNOSTICS
 
-On a partial or empty read, unless the
-.B -q
-option is specified, a diagnostic message is printed. Then, the program exits
-unless the
+On a partial or empty read, a diagnostic message is printed. Then, the program
+exits unless the
 .B -n
 option is specified.
 
@@ -128,20 +108,6 @@ option may be specified. In this event, the following format is used instead:
 {ASCII line feed}
 .RE
 
-If the
-.B -d
-option is specified, debug information will be printed at the beginning of
-execution. This output 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
-argv0=dj
-in=<stdin>      ibs=1024        skip=0  align=ff       count=0
-out=<stdout>    obs=1024        seek=0  debug= 3       noerror=0
-.RE
-
 In non-recoverable errors that don\(cqt pertain to the read-write cycle, a
 diagnostic message is printed and the program exits with the appropriate
 .BR sysexits.h (3)
@@ -156,9 +122,7 @@ is specified along with the
 option and a count, actual byte output is the product of the count and the input
 block size and therefore may be lower than expected. If the
 .B -a
-or
-.B -A
-options are specified, this could make written data nonsensical.
+option is specified, this could make written data nonsensical.
 .\"
 .SH CAVEATS
 

docs/fop.1

@@ -22,7 +22,7 @@ Performs operations on specified fields in data read from the standard input.
 .\"
 .SH OPTIONS
 
-.IP \fB-d\fP
+.IP \fB-d\fP\ \fIdelimiter\fP
 Sets a delimiter by which the input data will be split into fields. The default
 is an ASCII record separator.
 .\"

docs/intcmp.1

@@ -11,9 +11,7 @@ intcmp \(en compare integers
 .SH SYNOPSIS
 
 intcmp
-.RB ( -egl )
-.RB [ integer ]
-.RB [ integer... ]
+.RB [ -egl ]\ integer\ integer...
 .SH DESCRIPTION
 Compare integers to each other.
 .\"

docs/mm.1

@@ -10,11 +10,9 @@ mm \(en middleman
 .SH SYNOPSIS
 
 mm
-.RB ( -aenu )
-.RB ( -i
-.RB [ input ])
-.RB ( -o
-.RB [ output ])
+.RB [ -aenu ]
+.RB [ -i\ input ]
+.RB [ -o\ output ]
 .\"
 .SH DESCRIPTION
 
@@ -26,10 +24,10 @@ Catenate input files and write them to the start of each output file or stream.
 Opens subsequent outputs for appending rather than updating.
 .IP \fB-e\fP
 Use the standard error as an output.
-.IP \fB-i\fP
+.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
+.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-u\fP

docs/npc.1

@@ -11,7 +11,7 @@ npc \(en show non-printing characters
 .SH SYNOPSIS
 
 npc
-.RB ( -et )
+.RB [ -et ]
 .\"
 .SH DESCRIPTION
 

docs/scrut.1

@@ -10,8 +10,8 @@ scrut \(en scrutinize file properties
 .SH SYNOPSIS
 
 scrut
-.RB ( -LSbcdefgkprsuwx )
-.RB [ file... ]
+.RB [ -LSbcdefgkprsuwx ]
+.B file...
 .\"
 .SH DESCRIPTION
 

docs/str.1

@@ -11,8 +11,7 @@ str \(en test string arguments
 .SH SYNOPSIS
 
 str
-.RB [ type ]
-.RB [ string... ]
+.B type string...
 .\"
 .SH DESCRIPTION
 

docs/strcmp.1

@@ -11,8 +11,7 @@ strcmp \(en compare strings
 .SH SYNOPSIS
 
 strcmp
-.RM [ string ]
-.RB [ strings... ]
+.B string string...
 .\"
 .SH DESCRIPTION
 

docs/swab.1

@@ -11,11 +11,8 @@ swab \(en swap bytes
 .SH SYNOPSIS
 
 swab
-.RB ( -f )
-.RB ( -w
-.R [
-.B word size
-.R ])
+.RB [ -f ]
+.RB [ -w\ word_size ]
 .\"
 .SH DESCRIPTION
 
@@ -25,11 +22,10 @@ Swap the latter and former halves of a block of bytes.
 
 .IP \fB-f\fP
 Ignore SIGINT signal.
-.IP \fB-w\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 by 2, otherwise the block of bytes being processed can\(cqt be
-halved.
+.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
+by 2, otherwise the block of bytes being processed can\(cqt be halved.
 .\"
 .SH EXAMPLES
 

src/dj.c

@@ -16,7 +16,6 @@
  * along with this program. If not, see https://www.gnu.org/licenses/.
  */
 
-#include <ctype.h> /* isupper(3), tolower(3) */
 #include <errno.h> /* errno */
 #include <fcntl.h> /* open(2) */
 #include <stdio.h> /* fprintf(3), stderr */
@@ -25,8 +24,12 @@
 #include <sysexits.h> /* EX_OK, EX_USAGE */
 #include <unistd.h> /* close(2), getopt(3), lseek(2), read(2), write(2),
                      * optarg, optind, STDIN_FILENO, STDOUT_FILENO */
+#include <sys/stat.h> /* S_IRGRP, S_IROTH, S_IRUSR, S_IWGRP, S_IWOTH,
+                         S_IWUSR */
 extern int errno;
 
+char *program_name = "dj";
+
 /* dj uses two structures that respectively correspond to the reading and
  * writing ends of its jockeyed "pipe". User-configurable members are noted
  * with their relevant options. */
@@ -41,56 +44,17 @@ struct Io{
 	int prec;		/* partial records processed */
 	int rec;		/* records processed */
 	long seek;		/* bytes to seek/skip (will be 0 after skippage) (-sS) */
-} ep[2]; /* "engineered pipe"; also "extended play", for the deejay */
+}; 
 
-/* Additionally, the following global variables are used to store user options.
- */
+/* To be assigned to main:fmt_output and used with output(). */
+static char *fmt_asv   = "%d\037%d\036%d\037%d\035%d\036%d\034";
+static char *fmt_human = "%d+%d > %d+%d; %d > %d\n";
 
-/* (-a)  */ static int align; /* Only the lower 8b are used but align is
-                               * negative if no alignment is being done. */
-
-/* (-c)  */ static int count; /* 0 if dj(1) runs until no more reads are
-                               * possible. */
-
-/* ASCII field separator delimited statistics */
-            static char *fmt_asv   = "%d\037%d\036%d\037%d\035%d\036%d\034";
-/* human-readable statistics */
-            static char *fmt_human = "%d+%d > %d+%d; %d > %d\n";
-/* pointer to chosen formatting */
-/* (-H)  */ static char *fmt_output; /* fmt_asv (default) or fmt_human (-H) */
-
-/* (-dq) */ static char debug;       /*
- *  -d  increments             dj -qq | 0 - no diagnostic output whatsoever
- *   -q decrements             dj -q  | 1 - typical output without
- *                                    |     notifications on partial reads or
- *                                    |     writes
- *                             dj     | 2 - typical output (default)
- *                             dj -d  | 3 - verbose status messages */
-
-/* (-n)  */ static char noerror;     /* 0 - exits on partial reads or writes
-                                      *     (default)
-                                      * 1 - retries on partial reads/writes
-                                      *     (-n) */
-
-/* Non-configurable defaults. */
-#define bs_default 1024 /* GNU dd(1) default; twice POSIX but a neat 2^10 */
-static char *program_name = "<no argv[0]>";
 static char *stdin_name = "<stdin>";
 static char *stdout_name = "<stdout>";
-static int read_flags = O_RDONLY; /* These flags are consistent with Busybox */
-static int write_flags = O_WRONLY | O_CREAT; /* dd(1). */
 
-/* Macro to set defaults for user-configurable options. */
-#define setdefaults do{ \
-	align = -1; \
-	count = 0; \
-	debug = 2; \
-	fmt_output = fmt_asv; \
-	noerror = 0; \
-	ep[0].fl = read_flags; \
-	Io_setdefaults(&ep[0]); \
-	ep[1].fl = write_flags; \
-	Io_setdefaults(&ep[1]); }while(0)
+static int read_flags = O_RDONLY; /* Consistent with Busybox dd(1). */
+static int write_flags = O_WRONLY | O_CREAT;
 
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 
@@ -104,8 +68,8 @@ static int write_flags = O_WRONLY | O_CREAT; /* dd(1). */
  * particular io[2] used in main. Error conditions are not checked because this
  * is only used when the program is about to terminate (hence its name). */
 #define terminate(io) do{ \
-	Io_buffree(&(io)[0]); \
-	Io_buffree(&(io)[1]); \
+	free((io[0]).buf); \
+	free((io[1]).buf); \
 	Io_fdclose(&(io)[0]); \
 	Io_fdclose(&(io)[1]); }while(0)
 
@@ -116,15 +80,6 @@ Io_bufalloc(struct Io *io){
 	return (io->buf = malloc(io->bs * (sizeof *io->buf)));
 }
 
-/* Frees *io's buffer. Returns io. */
-static struct Io *
-Io_buffree(struct Io *io){
-
-	free(io->buf);
-
-	return io;
-}
-
 /* Fills the unused portion of io's buffer with padding, updating io->bufuse.
  * Returns io. */
 static struct Io *
@@ -193,18 +148,18 @@ Io_fdopen(struct Io *io, char *fn){
 	return fd;
 }
 
-/* Seeks io->seek bytes through *io's file descriptor, (counter-intuitively)
- * returning -1 if successful and a sysexits.h exit code if an unrecoverable
- * error occurred. io->buf will be cleared of useful bytes and io->seek will
- * be set to zero to indicate the seek occurred. */
-static int
+/* Seeks io->seek bytes through *io's file descriptor, subtracting the number
+ * of sought bytes from io->seek. This procedure leaves garbage in io->buf. */
+static void
 Io_fdseek(struct Io *io){
-	int (*op)(int, void *, size_t);
 	
-	if(!fdisstd(io->fd) && lseek(io->fd, io->seek, SEEK_SET) != -1)
-		return -1;
+	if(io->seek != 0
+			|| (!fdisstd(io->fd) && lseek(io->fd, io->seek, SEEK_SET) != -1))
+		return;
+
+	if(io->fl == write_flags)
+		memset(io->buf, '\0', io->bs);
 
-	/* 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),
@@ -223,12 +178,11 @@ Io_fdseek(struct Io *io){
 				/* 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;
 
-	return -1;
+	return;
 }
 
 /* Reads io->bs bytes from *io's file descriptor into io->buf, storing the
@@ -242,23 +196,6 @@ Io_read(struct Io *io){
 	return io;
 }
 
-/* Sets the variables in a struct *io to the defaults. Identifies the read/
- * write ends of the "pipe" by checking io->fl. Returns io. */
-static struct Io *
-Io_setdefaults(struct Io *io){
-
-	io->bs = bs_default;
-	io->buf = NULL;
-	io->bytes = 0;
-	io->fd = (io->fl == read_flags) ? STDIN_FILENO : STDOUT_FILENO;
-	io->fn = (io->fl == read_flags) ? stdin_name   : stdout_name;
-	io->prec = 0;
-	io->rec = 0;
-	io->seek = 0;
-
-	return io;
-}
-
 /* Writes io->bufuse units from io->buf to io->fd, permuting any unwritten
  * bytes to the start of io->buf and updating io->bufuse. If io->bufuse doesn't
  * change, errno will probably be set. Returns io. */
@@ -284,14 +221,13 @@ oserr(char *s){
 }
 
 /* Prints statistics regarding the use of dj, particularly partially and
- * completely read and written records, accessing debug, ep, and fmt_output. */
+ * completely read and written records. */
 static void
-output(void){
+output(struct Io io[2], char *fmt){
 
-	if(debug >= 1)
-		fprintf(stderr, fmt_output,
-			ep[0].rec, ep[0].prec, ep[1].rec, ep[1].prec,
-			ep[0].bytes, ep[1].bytes);
+	fprintf(stderr, fmt,
+		io[0].rec, io[0].prec, io[1].rec, io[1].prec,
+		io[0].bytes, io[1].bytes);
 
 	return;
 }
@@ -311,142 +247,147 @@ parse(char *s){
 }
 
 static int
-usage(void){
+usage(char *s){
 
-	fprintf(stderr, "Usage: %s (-AdfHqQ) (-a [byte]) (-c [count])\n"
-		"\t(-i [input file]) (-b [input block size]) (-s [input offset])\n"
-		"\t(-o [output file]) (-B [output block size]) (-S [output offset])\n",
+	fprintf(stderr, "Usage: %s [-Hn] [-a byte] [-c count]\n"
+		"\t[-i file] [-b block_size] [-s offset]\n"
+		"\t[-o file] [-B block_size] [-S offset]\n",
 		program_name);
 
 	return EX_USAGE;
 }
 
 int main(int argc, char *argv[]){
-	int c;
-	int i;
+	int align; /* low 8b used, negative if no alignment is being done */
+	int count; /* 0 if dj(1) runs until no more reads are possible */
+	char *fmt_output; /* == fmt_asv (default) or fmt_human (-H) */
+	size_t i; /* side of io being modified */
+	struct Io io[2];
+	char noerror; /* 0=exits (default) 1=retries on partial reads or writes */
 
-	setdefaults;
+	/* Set defaults. */
+	align = -1;
+	count = 0;
+	fmt_output = fmt_asv;
+	noerror = 0;
+	for(i = 0; i < 2; ++i){
+		io[i].bs = 1024 /* 1 KiB */; /* GNU dd(1) default; POSIX says 512B */
+		io[i].bytes = 0;
+		io[i].fd = i ? STDIN_FILENO : STDOUT_FILENO;
+		io[i].fn = i ? stdin_name   : stdout_name;
+		io[i].fl = i ? read_flags   : write_flags;
+		io[i].prec = 0;
+		io[i].rec = 0;
+		io[i].seek = 0;
+	}
 
 	if(argc > 0){
+		int c;
+
 		program_name = argv[0];
-		while((c = getopt(argc, argv, "a:Ab:B:c:di:hHnqs:S:o:")) != -1)
+		while((c = getopt(argc, argv, "a:b:B:c:i:hHns:S:o:")) != -1)
 			switch(c){
-			case 'i': case 'o':
-				i = (c == 'o');
+			case 'i': case 'o': i = (c == 'o');
 				if(optarg[0] == '-' && optarg[1] == '\0'){ /* optarg == "-" */
-					ep[i].fd = (i == 0) ? STDIN_FILENO : STDOUT_FILENO;
-					ep[i].fn = (i == 0) ? stdin_name   : stdout_name;
+					io[i].fd = i ? STDIN_FILENO : STDOUT_FILENO;
+					io[i].fn = i ? stdin_name   : stdout_name;
 					break;
-				}else if(Io_fdopen(&ep[i], optarg) != -1)
+				}else if(Io_fdopen(&io[i], optarg) != -1)
 					break;
-				terminate(ep);
+				terminate(io);
 				return oserr(optarg);
-			case 'A': align = '\0'; break;
-			case 'd': ++debug; break;
 			case 'n': noerror = 1; break;
 			case 'H': fmt_output = fmt_human; break;
-			case 'q': --debug; break;
 			case 'a':
-				if(optarg[0] != '\0' && optarg[1] == '\0'){
+				if(optarg[0] == '\0' || optarg[1] == '\0'){
 					align = optarg[0];
 					break;
 				}
 				/* FALLTHROUGH */
-			case 'c': case 'b': case 's': case 'B': case 'S':
+			case 'c': case 'b': case 's': case 'B': case 'S': /* numbers */
 				if(c == 'c' && (count = parse(optarg)) >= 0)
 					break;
-				i = isupper(c);
-				c = tolower(c);
-				if((c == 'b' && (ep[i].bs = parse(optarg)) > 0)
-						|| (c == 's' && (ep[i].seek = parse(optarg)) >= 0))
+				i = (c >= 'A' && c <= 'Z'); /* uppercase changes output */
+				c &= 0x20 /* 0b 0010 0000 */; /* (ASCII) make lowercase */
+				if((c == 'b' && (io[i].bs = parse(optarg)) > 0)
+						|| (c == 's' && (io[i].seek = parse(optarg)) >= 0))
 					break;
 				/* FALLTHROUGH */
 			default:
-				terminate(ep);
-				return usage();
+				terminate(io);
+				return usage(program_name);
 			}
 	}
 
-	if(debug >= 3)
-		fprintf(stderr,
-			"argv0=%s\n"
-			"in=%s\tibs=%d\tskip=%ld\talign=%hhx\tcount=%d\n"
-			"out=%s\tobs=%d\tseek=%ld\tdebug=%2d\tnoerror=%d\n",
-			program_name,
-			ep[0].fn, ep[0].bs, ep[0].seek, align, count,
-			ep[1].fn, ep[1].bs, ep[1].seek, debug, noerror);
-
 	if(argc > optind){
-		terminate(ep);
-		return usage();
+		terminate(io);
+		return usage(program_name);
 	}
 
-	for(i = 0; i <= 1; ++i){
-		if(Io_bufalloc(&ep[i]) == NULL){
+	for(i = 0; i < 2; ++i){
+		if(Io_bufalloc(&io[i]) == NULL){
 			fprintf(stderr, "%s: Failed to allocate %d bytes\n",
-				program_name, ep[i].bs);
-			terminate(ep);
+				program_name, io[i].bs);
+			terminate(io);
 			return EX_OSERR;
-		}else if(ep[i].seek > 0)
-			switch(Io_fdseek(&ep[i])){
-			case EX_OK:
-				output();
-				terminate(ep);
-				return EX_OK;
+		}else if(io[i].seek > 0)
+			Io_fdseek(&io[i]);
+			if(io[i].seek > 0){
+				terminate(io);
+				return oserr(io[i].fn);
 			}
 	}
 
 	do{	/* read */
-		Io_read(&ep[0]);
-		if(!noerror && ep[0].bufuse == 0)
-			Io_read(&ep[0]); /* second chance */
-		if(ep[0].bufuse == 0) /* that's all she wrote */
+		Io_read(&io[0]);
+		if(!noerror && io[0].bufuse == 0)
+			Io_read(&io[0]); /* second chance */
+		if(io[0].bufuse == 0) /* that's all she wrote */
 			break;
-		else if(ep[0].bufuse < ep[0].bs){
-			++ep[0].prec;
-			if(debug >= 2){
-				fprintf(stderr, "%s: Partial read:\n\t", program_name);
-				output();
-			}
+		else if(io[0].bufuse < io[0].bs){
+			++io[0].prec;
+			fprintf(stderr, "%s: Partial read:\n\t", program_name);
+			output(io, fmt_output);
 			if(!noerror)
 				count = 1;
 			if(align >= 0)
-				Io_bufrpad(&ep[0], align);
+				Io_bufrpad(&io[0], align);
 		}else
-			++ep[0].rec;
+			++io[0].rec;
 
 		/* write */
-		do{	if(ep[1].bs > ep[0].bs){ /* io[1].bs > io[0].bs */
-				Io_bufxapp(&ep[1], &ep[0]);
-				if(ep[0].bs + ep[1].bufuse <= ep[1].bs && count != 1)
+		do{
+			int t;
+
+			if(io[1].bs > io[0].bs){
+				Io_bufxapp(&io[1], &io[0]);
+				if(io[0].bs + io[1].bufuse <= io[1].bs && count != 1)
 					continue; /* we could write more */
 			}else
-				Io_bufxfer(&ep[1], &ep[0], MIN(ep[0].bufuse, ep[1].bs));
+				Io_bufxfer(&io[1], &io[0], MIN(io[0].bufuse, io[1].bs));
 
-			c = ep[1].bufuse;
-			Io_write(&ep[1]);
-			if(!noerror && ep[1].bufuse == c)
-				Io_write(&ep[1]); /* second chance */
-			if(c == ep[1].bufuse){ /* no more love */
+			t = io[1].bufuse;
+			Io_write(&io[1]);
+			if(!noerror && io[1].bufuse == t)
+				Io_write(&io[1]); /* second chance */
+			if(t == io[1].bufuse){ /* no more love */
 				count = 1;
 				break;
-			}else if(c > ep[1].bufuse && ep[1].bufuse > 0){
-				ep[1].prec += 1;
-				if(debug >= 2){
-					fprintf(stderr, "%s: Partial write:\n\t", program_name);
-					output();
-				}
+			}else if(t > io[1].bufuse && io[1].bufuse > 0){
+				io[1].prec += 1;
+				fprintf(stderr, "%s: Partial write:\n\t", program_name);
+				output(io, fmt_output);
 				if(!noerror)
 					count = 1;
-			}else if(ep[1].bufuse == 0 && c < ep[1].bs)
-				++ep[1].prec;
+			}else if(io[1].bufuse == 0 && t < io[1].bs)
+				++io[1].prec;
 			else
-				++ep[1].rec;
-		}while(ep[0].bufuse > 0);
+				++io[1].rec;
+		}while(io[0].bufuse > 0);
 	}while(count == 0 || --count > 0);
 
-	output();
-	terminate(ep);
+	output(io, fmt_output);
+	terminate(io);
 
 	return EX_OK;
 }

src/intcmp.c

@@ -52,7 +52,7 @@ int main(int argc, char *argv[]){
 
 	if(optind + 2 /* ref cmp */ > argc){
 usage:		fprintf(stderr,
-			"Usage: %s (-eghl) [integer] [integer...]\n",
+			"Usage: %s [-egl] integer integer...\n",
 			argv[0] == NULL ? program_name : argv[0]);
 		return EX_USAGE;
 	}

src/mm.c

@@ -110,7 +110,7 @@ oserr(char *s, char *r){
  * returns an exit status appropriate for a usage error. */
 int usage(char *s){
 
-	fprintf(stderr, "Usage: %s (-aenu) (-i [input])... (-o [output])...\n", s);
+	fprintf(stderr, "Usage: %s [-aenu] [-i input]... [-o output]...\n", s);
 
 	return EX_USAGE;
 }

src/npc.c

@@ -39,7 +39,7 @@ int main(int argc, char *argv[]){
 			}
 
 	if(argc > optind){
-usage:		fprintf(stderr, "Usage: %s (-eht)\n", argv[0]);
+usage:		fprintf(stderr, "Usage: %s [-et]\n", argv[0]);
 		return EX_USAGE;
 	}
 

src/scrut.c

@@ -66,7 +66,7 @@ int main(int argc, char *argv[]){
 			if(ops[i] == 'e')
 				continue;
 			else if(ops[i] == 'h'){
-usage:				fprintf(stderr, "Usage: %s (-%s) [file...]\n",
+usage:				fprintf(stderr, "Usage: %s [-%s] file...\n",
 					argv[0] == NULL
 						? program_name
 						: argv[0],

src/str.c

@@ -56,7 +56,7 @@ int main(int argc, char *argv[]){
 				goto pass;
 	}
 
-	fprintf(stderr, "Usage: %s [type] [string...]\n",
+	fprintf(stderr, "Usage: %s type string...\n",
 		argv[0] == NULL ? program_name : argv[0]);
 
 	return EX_USAGE;

src/strcmp.c

@@ -8,7 +8,7 @@ int main(int argc, char *argv[]){
 	int i;
 
 	if(argc < 3){
-		fprintf(stderr, "Usage: %s [string] [string...]\n",
+		fprintf(stderr, "Usage: %s string string...\n",
 			argv[0] == NULL ? program_name : argv[0]);
 		return EX_USAGE;
 	}

src/swab.rs

@@ -35,7 +35,7 @@ fn oserr(s: &str, e: Error) -> ExitCode {
 }
 
 fn usage(s: &str) -> ExitCode {
-	eprintln!("Usage: {} (-f) (-w [wordsize])", s);
+	eprintln!("Usage: {} [-f] [-w word_size]", s);
 	ExitCode::from(EX_USAGE as u8)
 }