Add a seq(1) command, similar to what is present in GNU and Plan9.

Adapted from the NetBSD version with some changes from FreeBSD.
OK gnezdo@

4 files changed, 624 insertions, 2 deletions

diff --git a/usr.bin/Makefile b/usr.bin/Makefile
index 22027a4f753..a2173f9c55c 100644
--- a/usr.bin/Makefile
+++ b/usr.bin/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.165 2021/10/13 15:04:53 kn Exp $
+#	$OpenBSD: Makefile,v 1.166 2022/02/22 15:15:34 millert Exp $
 
 .include <bsd.own.mk>
 
@@ -21,7 +21,7 @@ SUBDIR= apply arch at aucat audioctl awk banner \
 	pkg-config pkill \
 	pr printenv printf quota radioctl rcs rdist rdistd \
 	readlink realpath renice rev rpcgen rpcinfo rs rsync rup rusers rwall \
-	sdiff script sed sendbug shar showmount signify skey \
+	sdiff seq script sed sendbug shar showmount signify skey \
 	skeyaudit skeyinfo skeyinit sndioctl sndiod snmp \
 	sort spell split ssh stat su systat \
 	tail talk tcpbench tee telnet tftp tic time timeout \
diff --git a/usr.bin/seq/Makefile b/usr.bin/seq/Makefile
new file mode 100644
index 00000000000..96ad1236c7e
--- /dev/null
+++ b/usr.bin/seq/Makefile
@@ -0,0 +1,8 @@
+#	$OpenBSD: Makefile,v 1.1 2022/02/22 15:15:34 millert Exp $
+
+PROG=	seq
+CFLAGS+= -Wall
+LDADD+=	-lm
+DPADD+=	${LIBM}
+
+.include <bsd.prog.mk>
diff --git a/usr.bin/seq/seq.1 b/usr.bin/seq/seq.1
new file mode 100644
index 00000000000..4996b97b38e
--- /dev/null
+++ b/usr.bin/seq/seq.1
@@ -0,0 +1,197 @@
+.\"	$OpenBSD: seq.1,v 1.1 2022/02/22 15:15:34 millert Exp $
+.\"
+.\" Copyright (c) 2005 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Brian Ginsbach.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd $Mdocdate: February 22 2022 $
+.Dt SEQ 1
+.Os
+.Sh NAME
+.Nm seq
+.Nd print sequences of numbers
+.Sh SYNOPSIS
+.Nm
+.Op Fl w
+.Op Fl f Ar format
+.Op Fl s Ar string
+.Op Ar first Op Ar incr
+.Ar last
+.Sh DESCRIPTION
+The
+.Nm
+utility prints a sequence of numbers, one per line
+.Pq default ,
+from
+.Ar first
+.Pq default 1 ,
+to near
+.Ar last
+as possible, in increments of
+.Ar incr
+.Pq default 1 .
+When
+.Ar first
+is larger than
+.Ar last ,
+the default
+.Ar incr
+is -1.
+.Pp
+All numbers are interpreted as floating point.
+.Pp
+Normally, integer values are printed as decimal integers.
+.Pp
+The
+.Nm
+utility accepts the following options:
+.Bl -tag -width Ar
+.It Fl f Ar format , Fl -format Ar format
+Use a
+.Xr printf 3
+style
+.Ar format
+to print each number.
+Only the
+.Cm A ,
+.Cm a ,
+.Cm E ,
+.Cm e ,
+.Cm F ,
+.Cm f ,
+.Cm G ,
+.Cm g ,
+and
+.Cm %
+conversion characters are valid, along with any optional
+flags and an optional numeric minimum field width or precision.
+The
+.Ar format
+can contain character escape sequences in backslash notation as
+defined in
+.St -ansiC .
+The default is
+.Cm %g .
+.It Fl s Ar string , Fl -separator Ar string
+Use
+.Ar string
+to separate numbers.
+The
+.Ar string
+can contain character escape sequences in backslash notation as
+defined in
+.St -ansiC .
+The default is
+.Cm \en .
+.It Fl w , Fl -fixed-width
+Equalize the widths of all numbers by padding with zeros as necessary.
+This option has no effect with the
+.Fl f
+option.
+If any sequence numbers will be printed in exponential notation,
+the default conversion is changed to
+.Cm %e .
+.It Fl -help
+Display the program usage and exit.
+.It Fl -version
+Display the verion number and exit.
+.El
+.Sh EXIT STATUS
+.Ex -std
+.Sh EXAMPLES
+Generate a sequence from 1 to 3 (inclusive) with a default increment of 1:
+.Bd -literal -offset indent
+# seq 1 3
+1
+2
+3
+.Ed
+.Pp
+Generate a sequence from 3 to 1 (inclusive) with a default increment of -1:
+.Bd -literal -offset indent
+# seq 3 1
+3
+2
+1
+.Ed
+.Pp
+Generate a sequence from 0 to 0.1 (inclusive) with an increment of 0.05 and padding
+with leading zeroes.
+.Bd -literal -offset indent
+# seq -w 0 .05 .1
+0.00
+0.05
+0.10
+.Ed
+.Pp
+Generate a sequence from 1 to 3 (inclusive) with a default increment of 1,
+and a custom separator string:
+.Bd -literal -offset indent
+# seq -s " " 1 3
+1 2 3
+.Ed
+.Pp
+Generate a sequence from 1 to 2 (inclusive) with an increment of 0.2 and
+print the results with two digits after the decimal point (using a
+.Xr printf 3
+style format):
+.Bd -literal -offset indent
+# seq -f %.2f 1 0.2 2
+1.00
+1.20
+1.40
+1.60
+1.80
+2.00
+.Ed
+.Sh SEE ALSO
+.Xr jot 1 ,
+.Xr printf 1 ,
+.Xr printf 3
+.Sh HISTORY
+A
+.Nm
+command appeared in
+.At v8 .
+This version of
+.Nm
+appeared in
+.Nx 3.0
+and was ported to
+.Ox 7.1 .
+It was based on the command of the same name in
+Plan 9 from Bell Labs and the GNU core utilities.
+The GNU
+.Nm
+command first appeared in the 1.13 shell utilities release.
+.Sh BUGS
+The
+.Fl w
+option does not handle the transition from pure floating point
+to exponent representation very well.
+The
+.Nm
+utility is not bug for bug compatible with other implementations.
diff --git a/usr.bin/seq/seq.c b/usr.bin/seq/seq.c
new file mode 100644
index 00000000000..5ca075f7d80
--- /dev/null
+++ b/usr.bin/seq/seq.c
@@ -0,0 +1,417 @@
+/*	$OpenBSD: seq.c,v 1.1 2022/02/22 15:15:34 millert Exp $	*/
+
+/*-
+ * Copyright (c) 2005 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Brian Ginsbach.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <getopt.h>
+#include <math.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define VERSION	"1.0"
+#define ZERO	'0'
+#define SPACE	' '
+
+#define MAXIMUM(a, b)	(((a) < (b))? (b) : (a))
+#define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
+#define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
+#define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
+
+/* Globals */
+
+static const char *decimal_point = ".";	/* default */
+static char default_format[] = { "%g" };	/* default */
+
+static const struct option long_opts[] =
+{
+	{"format",	required_argument,	NULL, 'f'},
+	{"help",	no_argument,		NULL, 'h'},
+	{"separator",	required_argument,	NULL, 's'},
+	{"version",	no_argument,		NULL, 'v'},
+	{"equal-width",	no_argument,		NULL, 'w'},
+	{NULL,		no_argument,		NULL, 0}
+};
+
+/* Prototypes */
+
+static double e_atof(const char *);
+
+static int decimal_places(const char *);
+static int numeric(const char *);
+static int valid_format(const char *);
+
+static char *generate_format(double, double, double, int, char);
+
+static __dead void usage(int error);
+
+/*
+ * The seq command will print out a numeric sequence from 1, the default,
+ * to a user specified upper limit by 1.  The lower bound and increment
+ * maybe indicated by the user on the command line.  The sequence can
+ * be either whole, the default, or decimal numbers.
+ */
+int
+main(int argc, char *argv[])
+{
+	int c = 0;
+	int equalize = 0;
+	double first = 1.0;
+	double last = 0.0;
+	double incr = 0.0;
+	double last_shown_value = 0.0;
+	double cur, step;
+	struct lconv *locale;
+	char *fmt = NULL;
+	const char *sep = "\n";
+	const char *term = "\n";
+	char *cur_print, *last_print;
+	char pad = ZERO;
+
+	/* Determine the locale's decimal point. */
+	locale = localeconv();
+	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
+		decimal_point = locale->decimal_point;
+
+	/*
+         * Process options, but handle negative numbers separately
+         * least they trip up getopt(3).
+         */
+	while ((optind < argc) && !numeric(argv[optind]) &&
+	    (c = getopt_long(argc, argv, "+f:s:w", long_opts, NULL)) != -1) {
+
+		switch (c) {
+		case 'f':	/* format (plan9/GNU) */
+			fmt = optarg;
+			equalize = 0;
+			break;
+		case 's':	/* separator (GNU) */
+			sep = optarg;
+			break;
+		case 'v':	/* version (GNU) */
+			printf("seq version %s\n", VERSION);
+			return 0;
+		case 'w':	/* equal width (plan9/GNU) */
+			if (fmt == NULL) {
+				if (equalize++)
+					pad = SPACE;
+			}
+			break;
+		case 'h':	/* help (GNU) */
+			usage(0);
+			break;
+		default:
+			usage(1);
+			break;
+		}
+	}
+
+	argc -= optind;
+	argv += optind;
+	if (argc < 1 || argc > 3)
+		usage(1);
+
+	last = e_atof(argv[argc - 1]);
+
+	if (argc > 1)
+		first = e_atof(argv[0]);
+	
+	if (argc > 2) {
+		incr = e_atof(argv[1]);
+		/* Plan 9/GNU don't do zero */
+		if (incr == 0.0)
+			errx(1, "zero %screment", (first < last)? "in" : "de");
+	}
+
+	/* default is one for Plan 9/GNU work alike */
+	if (incr == 0.0)
+		incr = (first < last) ? 1.0 : -1.0;
+
+	if (incr <= 0.0 && first < last)
+		errx(1, "needs positive increment");
+
+	if (incr >= 0.0 && first > last)
+		errx(1, "needs negative decrement");
+
+	if (fmt != NULL) {
+		if (!valid_format(fmt))
+			errx(1, "invalid format string: `%s'", fmt);
+		/*
+	         * XXX to be bug for bug compatible with Plan 9 add a
+		 * newline if none found at the end of the format string.
+		 */
+	} else
+		fmt = generate_format(first, incr, last, equalize, pad);
+
+	for (step = 1, cur = first; incr > 0 ? cur <= last : cur >= last;
+	    cur = first + incr * step++) {
+		if (cur != first)
+		    fputs(sep, stdout);
+		printf(fmt, cur);
+		last_shown_value = cur;
+	}
+
+	/*
+	 * Did we miss the last value of the range in the loop above?
+	 *
+	 * We might have, so check if the printable version of the last
+	 * computed value ('cur') and desired 'last' value are equal.  If they
+	 * are equal after formatting truncation, but 'cur' and
+	 * 'last_shown_value' are not equal, it means the exit condition of the
+	 * loop held true due to a rounding error and we still need to print
+	 * 'last'.
+	 */
+	asprintf(&cur_print, fmt, cur);
+	asprintf(&last_print, fmt, last);
+	if (strcmp(cur_print, last_print) == 0 && cur != last_shown_value) {
+		if (cur != first)
+		    fputs(sep, stdout);
+		fputs(last_print, stdout);
+	}
+	free(cur_print);
+	free(last_print);
+
+	fputs(term, stdout);
+
+	return 0;
+}
+
+/*
+ * numeric - verify that string is numeric
+ */
+static int
+numeric(const char *s)
+{
+	int seen_decimal_pt, decimal_pt_len;
+
+	/* skip any sign */
+	if (ISSIGN((unsigned char)*s))
+		s++;
+
+	seen_decimal_pt = 0;
+	decimal_pt_len = strlen(decimal_point);
+	while (*s) {
+		if (!isdigit((unsigned char)*s)) {
+			if (!seen_decimal_pt &&
+			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
+				s += decimal_pt_len;
+				seen_decimal_pt = 1;
+				continue;
+			}
+			if (ISEXP((unsigned char)*s)) {
+				s++;
+				if (ISSIGN((unsigned char)*s) ||
+				    isdigit((unsigned char)*s)) {
+					s++;
+					continue;
+				}
+			}
+			break;
+		}
+		s++;
+	}
+	return *s == '\0';
+}
+
+/*
+ * valid_format - validate user specified format string
+ */
+static int
+valid_format(const char *fmt)
+{
+	unsigned conversions = 0;
+
+	while (*fmt != '\0') {
+		/* scan for conversions */
+		if (*fmt != '%') {
+			fmt++;
+			continue;
+		}
+		fmt++;
+
+		/* allow %% but not things like %10% */
+		if (*fmt == '%') {
+			fmt++;
+			continue;
+		}
+
+		/* flags */
+		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
+			fmt++;
+		}
+
+		/* field width */
+		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
+			fmt++;
+		}
+
+		/* precision */
+		if (*fmt == '.') {
+			fmt++;
+			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
+				fmt++;
+			}
+		}
+
+		/* conversion */
+		switch (*fmt) {
+		    case 'A':
+		    case 'a':
+		    case 'E':
+		    case 'e':
+		    case 'F':
+		    case 'f':
+		    case 'G':
+		    case 'g':
+			/* floating point formats are accepted */
+			conversions++;
+			break;
+		    default:
+			/* anything else is not */
+			return 0;
+		}
+	}
+
+	/* PR 236347 -- user format strings must have a conversion */
+	return conversions == 1;
+}
+
+/*
+ * e_atof - convert an ASCII string to a double
+ *	exit if string is not a valid double, or if converted value would
+ *	cause overflow or underflow
+ */
+static double
+e_atof(const char *num)
+{
+	char *endp;
+	double dbl;
+
+	errno = 0;
+	dbl = strtod(num, &endp);
+
+	if (errno == ERANGE)
+		/* under or overflow */
+		err(2, "%s", num);
+	else if (*endp != '\0')
+		/* "junk" left in number */
+		errx(2, "invalid floating point argument: %s", num);
+
+	/* zero shall have no sign */
+	if (dbl == -0.0)
+		dbl = 0;
+	return dbl;
+}
+
+/*
+ * decimal_places - count decimal places in a number (string)
+ */
+static int
+decimal_places(const char *number)
+{
+	int places = 0;
+	char *dp;
+
+	/* look for a decimal point */
+	if ((dp = strstr(number, decimal_point))) {
+		dp += strlen(decimal_point);
+
+		while (isdigit((unsigned char)*dp++))
+			places++;
+	}
+	return places;
+}
+
+/*
+ * generate_format - create a format string
+ *
+ * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
+ * when "%g" prints as "%e" (this way no width adjustments are made)
+ */
+static char *
+generate_format(double first, double incr, double last, int equalize, char pad)
+{
+	static char buf[256];
+	char cc = '\0';
+	int precision, width1, width2, places;
+
+	if (equalize == 0)
+		return default_format;
+
+	/* figure out "last" value printed */
+	if (first > last)
+		last = first - incr * floor((first - last) / incr);
+	else
+		last = first + incr * floor((last - first) / incr);
+
+	snprintf(buf, sizeof(buf), "%g", incr);
+	if (strchr(buf, 'e'))
+		cc = 'e';
+	precision = decimal_places(buf);
+
+	width1 = snprintf(buf, sizeof(buf), "%g", first);
+	if (strchr(buf, 'e'))
+		cc = 'e';
+	if ((places = decimal_places(buf)))
+		width1 -= (places + strlen(decimal_point));
+
+	precision = MAXIMUM(places, precision);
+
+	width2 = snprintf(buf, sizeof(buf), "%g", last);
+	if (strchr(buf, 'e'))
+		cc = 'e';
+	if ((places = decimal_places(buf)))
+		width2 -= (places + strlen(decimal_point));
+
+	/* XXX if incr is floating point fix the precision */
+	if (precision) {
+		snprintf(buf, sizeof(buf), "%%%c%d.%d%c", pad,
+		    MAXIMUM(width1, width2) + (int) strlen(decimal_point) +
+		    precision, precision, (cc) ? cc : 'f');
+	} else {
+		snprintf(buf, sizeof(buf), "%%%c%d%c", pad,
+		    MAXIMUM(width1, width2), (cc) ? cc : 'g');
+	}
+
+	return buf;
+}
+
+static __dead void
+usage(int error)
+{
+	fprintf(stderr,
+	    "usage: %s [-vw] [-f format] [-s string] [first [incr]] last\n",
+	    getprogname());
+	exit(error);
+}