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/* See LICENSE file for copyright and license details. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"
static int
digitsleft(const char *d)
{
int shift;
char *exp;
if (*d == '+')
d++;
exp = strpbrk(d, "eE");
shift = exp ? estrtonum(exp + 1, INT_MIN, INT_MAX) : 0;
return MAX(0, strspn(d, "-0123456789") + shift);
}
static int
digitsright(const char *d)
{
int shift, after;
char *exp;
exp = strpbrk(d, "eE");
shift = exp ? estrtonum(&exp[1], INT_MIN, INT_MAX) : 0;
after = (d = strchr(d, '.')) ? strspn(&d[1], "0123456789") : 0;
return MAX(0, after - shift);
}
static int
validfmt(const char *fmt)
{
int occur = 0;
literal:
while (*fmt)
if (*fmt++ == '%')
goto format;
return occur == 1;
format:
if (*fmt == '%') {
fmt++;
goto literal;
}
fmt += strspn(fmt, "-+#0 '");
fmt += strspn(fmt, "0123456789");
if (*fmt == '.') {
fmt++;
fmt += strspn(fmt, "0123456789");
}
if (*fmt == 'L')
fmt++;
switch (*fmt) {
case 'f': case 'F':
case 'g': case 'G':
case 'e': case 'E':
case 'a': case 'A':
occur++;
goto literal;
default:
return 0;
}
}
static void
usage(void)
{
eprintf("usage: %s [-f fmt] [-s sep] [-w] "
"[startnum [step]] endnum\n", argv0);
}
int
main(int argc, char *argv[])
{
double start, step, end, out, dir;
int wflag = 0, left, right;
char *tmp, ftmp[BUFSIZ], *fmt = ftmp;
const char *starts = "1", *steps = "1", *ends = "1", *sep = "\n";
ARGBEGIN {
case 'f':
if (!validfmt(tmp=EARGF(usage())))
eprintf("%s: invalid format\n", tmp);
fmt = tmp;
break;
case 's':
sep = EARGF(usage());
break;
case 'w':
wflag = 1;
break;
default:
usage();
} ARGEND
switch (argc) {
case 3:
steps = argv[1];
argv[1] = argv[2];
/* fallthrough */
case 2:
starts = argv[0];
argv++;
/* fallthrough */
case 1:
ends = argv[0];
break;
default:
usage();
}
start = estrtod(starts);
step = estrtod(steps);
end = estrtod(ends);
dir = (step > 0) ? 1.0 : -1.0;
if (step == 0 || start * dir > end * dir)
return 1;
if (fmt == ftmp) {
right = MAX(digitsright(starts),
MAX(digitsright(ends),
digitsright(steps)));
if (wflag) {
left = MAX(digitsleft(starts), digitsleft(ends));
snprintf(ftmp, sizeof ftmp, "%%0%d.%df",
right + left + (right != 0), right);
} else
snprintf(ftmp, sizeof ftmp, "%%.%df", right);
}
for (out = start; out * dir <= end * dir; out += step) {
if (out != start)
fputs(sep, stdout);
printf(fmt, out);
}
putchar('\n');
return fshut(stdout, "<stdout>");
}
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