sbase/seq.c
stateless 7216a53a7e Remove unnecessary exit(1) in usage()
Signed-off-by: Christoph Lohmann <20h@r-36.net>
2013-06-19 19:58:19 +02:00

171 lines
2.8 KiB
C

/* See LICENSE file for copyright and license details. */
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "util.h"
static int digitsleft(const char *);
static int digitsright(const char *);
static double estrtod(const char *);
static bool validfmt(const char *);
static void
usage(void)
{
eprintf("usage: %s [-f format] [-s sep] [-w width] first"
" [inc [last]]\n", argv0);
}
int
main(int argc, char *argv[])
{
const char *starts = "1", *steps = "1", *ends = "1", *sep = "\n";
bool wflag = false;
char ftmp[BUFSIZ], *fmt = ftmp;
double start, step, end, out, dir;
ARGBEGIN {
case 'f':
if(!validfmt(EARGF(usage())))
eprintf("%s: invalid format\n", ARGF());
fmt = ARGF();
break;
case 's':
sep = EARGF(usage());
break;
case 'w':
wflag = true;
break;
default:
usage();
} ARGEND;
switch(argc) {
case 3:
starts = argv[0];
argv++;
steps = argv[0];
argv++;
ends = argv[0];
argv++;
break;
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 EXIT_FAILURE;
if(fmt == ftmp) {
int right = MAX(digitsright(starts),
MAX(digitsright(ends),
digitsright(steps)));
if(wflag) {
int 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);
}
printf("\n");
return 0;
}
int
digitsleft(const char *d)
{
char *exp;
int shift;
if(*d == '+')
d++;
exp = strpbrk(d, "eE");
shift = exp ? atoi(&exp[1]) : 0;
return MAX(0, strspn(d, "-0123456789")+shift);
}
int
digitsright(const char *d)
{
char *exp;
int shift, after;
exp = strpbrk(d, "eE");
shift = exp ? atoi(&exp[1]) : 0;
after = (d = strchr(d, '.')) ? strspn(&d[1], "0123456789") : 0;
return MAX(0, after-shift);
}
double
estrtod(const char *s)
{
char *end;
double d;
d = strtod(s, &end);
if(end == s || *end != '\0')
eprintf("%s: not a real number\n", s);
return d;
}
bool
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 false;
}
}