commit f5b275d8876246cc06f45727052174755ac0eb17
parent b66c471c38b655c9161c3d3595479fe0e94576dc
Author: Anders Damsgaard <anders@adamsgaard.dk>
Date: Mon, 2 May 2022 14:04:15 +0200
range(1): make start and end values optional parameters
Diffstat:
| M | range.1 | | | 33 | +++++++++++++++++++++++++-------- |
| M | range.c | | | 46 | ++++++++++++++++++++++++++++------------------ |
2 files changed, 53 insertions(+), 26 deletions(-)
diff --git a/range.1 b/range.1
@@ -3,17 +3,21 @@
.Os
.Sh NAME
.Nm range
-.Nd generates an evenly spaced vector over a spacified range
+.Nd generates an evenly spaced vector over a range
.Sh SYNOPSIS
.Nm
.Ar cmd
+.Op Fl b
.Op Fl e
.Op Fl f Ar fmtstr
.Op Fl h
.Op Fl l
.Op Fl n Ar num
-.Ar min_val
+.Op Fl s
+.Oo
+.Op Ar min_val
.Ar max_val
+.Oc
.Sh DESCRIPTION
.Nm
generates floating-point numbers that are by default evenly distributed
@@ -21,6 +25,12 @@ in the linear, closed interval [
.Ar min_val
,
.Ar max_val ].
+If
+.Ar max_val
+is not specified, it is 1.
+If
+.Ar min_val
+is not specified, it is 0.
.Pp
The options are as follows:
.Bl -tag -width Ds
@@ -49,7 +59,7 @@ When including a format specifier (%..), only use forms that are
compatible with
.Vt double
types.
-The default format string is '%g'.
+The default format string is '%g\n'.
.It Fl h
Show usage information.
.It Fl l
@@ -58,11 +68,13 @@ and 10^max_val.
.It Fl n Ar num
Number of values to produce within the specified range.
The default is 10.
+.It Fl s
+Print the spacing between numbers and exit.
.El
.Sh EXAMPLES
-Generate four equally-spaced numbers in the closed range [0;1]:
+Generate four equally-spaced numbers in the closed default range [0;1]:
.Pp
-.Dl $ range -n 4 0 1
+.Dl $ range -n 4
.Dl 0
.Dl 0.33333
.Dl 0.66667
@@ -72,7 +84,7 @@ Same as the previous example, but with full
.Vt double
precision on a 64-bit system:
.Pp
-.Dl $ range -n 4 -f '%.17g' 0 1
+.Dl $ range -n 4 -f '%.17g\n' 0 1
.Dl 0
.Dl 0.33333333333333331
.Dl 0.66666666666666663
@@ -86,14 +98,19 @@ Generate four numbers in the range ]0;1[:
.Dl 0.6
.Dl 0.8
.Pp
+Print ten numbers in the interval [1;10] with spaces between values:
+.Pp
+.Dl $ range -f '%g ' 1 10
+.Dl 1 2 3 4 5 6 7 8 9 10
+.Pp
Repeat and modify a string three times:
.Pp
-.Dl $ range -n 3 -f 'The best number is %.0g' 1 3
+.Dl $ range -n 3 -f 'The best number is %.0g\n' 1 3
.Dl The best number is 1
.Dl The best number is 2
.Dl The best number is 3
.Pp
-Generate three numbers evenly distributed in logspace from 10^0 to 10^3:
+Generate three numbers evenly distributed in logspace from 10^0 to 10^2:
.Pp
.Dl $ range -l -n 3 0 2
.Dl 1
diff --git a/range.c b/range.c
@@ -13,16 +13,17 @@ char *argv0;
static void
usage(void)
{
- errx(1, "usage: %s [-b] [-e] [-f fmtstr] [-h] [-l] [-n num]"
- "min_val max_val\n", argv0);
+ errx(1, "usage: %s [-b] [-e] [-f fmtstr] [-h] [-l] [-n num] [-s]"
+ "[min_val] max_val\n", argv0);
}
int
main(int argc, char *argv[])
{
- int i, ret, n = 10, logrange = 0, openstart = 0, openend = 0;
- double minv, maxv, dx;
- char fmtstr[PATH_MAX] = "%g";
+ int i, ret, n = 10, logrange = 0, openstart = 0, openend = 0,
+ reportdx = 0;
+ double minv = 0.0, maxv = 1.0, dx;
+ char fmtstr[PATH_MAX] = "%g\n";
ARGBEGIN {
case 'b':
@@ -45,25 +46,34 @@ main(int argc, char *argv[])
case 'n':
n = atoi(EARGF(usage()));
break;
+ case 's':
+ reportdx = 1;
+ break;
default:
usage();
} ARGEND;
- if (argc == 2) {
+ if (argc > 2)
+ usage();
+ else if (argc == 2) {
minv = atof(argv[0]);
maxv = atof(argv[1]);
- dx = (maxv - minv)/(n - 1 + openend + openstart);
- if (minv >= maxv)
- errx(1, "min_val must be smaller than max_val");
- for (i = 0 + openstart; i < n + openstart; i++) {
- if (logrange)
- printf(fmtstr, pow(10, minv + i * dx));
- else
- printf(fmtstr, minv + i * dx);
- putchar('\n');
- }
- } else
- usage();
+ } else if (argc == 1)
+ maxv = atof(argv[0]);
+
+ dx = (maxv - minv)/(n - 1 + openend + openstart);
+ if (reportdx) {
+ printf(fmtstr, dx);
+ return 0;
+ }
+ if (minv >= maxv)
+ errx(1, "min_val must be smaller than max_val");
+ for (i = 0 + openstart; i < n + openstart; i++) {
+ if (logrange)
+ printf(fmtstr, pow(10, minv + i * dx));
+ else
+ printf(fmtstr, minv + i * dx);
+ }
return 0;
}
