Hi,
This seems like a textbook case for strtonum(3).
Change in behavior: when the start value is read from stdin,
trailing whitespace is now an error instead of being ignored.
I can revise the diff to stub out the trailing whitespace before
strtonum(3) sees it, though, if that's preferable.
Any takers?
--
Scott Cheloha
Index: games/primes/primes.c
===================================================================
RCS file: /cvs/src/games/primes/primes.c,v
retrieving revision 1.23
diff -u -p -r1.23 primes.c
--- games/primes/primes.c 31 Aug 2016 04:48:43 -0000 1.23
+++ games/primes/primes.c 30 Oct 2017 01:17:06 -0000
@@ -52,7 +52,6 @@
#include <ctype.h>
#include <err.h>
-#include <errno.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
@@ -96,10 +95,10 @@ __dead void usage(void);
int
main(int argc, char *argv[])
{
+ const char *errstr;
ubig start; /* where to start generating */
ubig stop; /* don't generate at or above this value */
int ch;
- char *p;
if (pledge("stdio", NULL) == -1)
err(1, "pledge");
@@ -117,43 +116,15 @@ main(int argc, char *argv[])
start = 0;
stop = BIG;
- /*
- * Convert low and high args. Strtoul(3) sets errno to
- * ERANGE if the number is too large, but, if there's
- * a leading minus sign it returns the negation of the
- * result of the conversion, which we'd rather disallow.
- */
switch (argc) {
case 2:
- /* Start and stop supplied on the command line. */
- if (argv[0][0] == '-' || argv[1][0] == '-')
- errx(1, "negative numbers aren't permitted.");
-
- errno = 0;
- start = strtoul(argv[0], &p, 10);
- if (errno)
- err(1, "%s", argv[0]);
- if (*p != '\0')
- errx(1, "%s: illegal numeric format.", argv[0]);
-
- errno = 0;
- stop = strtoul(argv[1], &p, 10);
- if (errno)
- err(1, "%s", argv[1]);
- if (*p != '\0')
- errx(1, "%s: illegal numeric format.", argv[1]);
- break;
- case 1:
- /* Start on the command line. */
- if (argv[0][0] == '-')
- errx(1, "negative numbers aren't permitted.");
-
- errno = 0;
- start = strtoul(argv[0], &p, 10);
- if (errno)
- err(1, "%s", argv[0]);
- if (*p != '\0')
- errx(1, "%s: illegal numeric format.", argv[0]);
+ stop = strtonum(argv[1], 0, BIG, &errstr);
+ if (errstr)
+ errx(1, "stop is %s: %s", errstr, argv[1]);
+ case 1: /* FALLTHROUGH */
+ start = strtonum(argv[0], 0, BIG, &errstr);
+ if (errstr)
+ errx(1, "start is %s: %s", errstr, argv[0]);
break;
case 0:
start = read_num_buf();
@@ -175,6 +146,7 @@ main(int argc, char *argv[])
ubig
read_num_buf(void)
{
+ const char *errstr;
ubig val;
char *p, buf[100]; /* > max number of digits. */
@@ -189,16 +161,9 @@ read_num_buf(void)
;
if (*p == '\0')
continue;
- if (*p == '-')
- errx(1, "negative numbers aren't permitted.");
- errno = 0;
- val = strtoul(buf, &p, 10);
- if (errno)
- err(1, "%s", buf);
- for (; isblank((unsigned char)*p); ++p)
- ;
- if (*p != '\0')
- errx(1, "%s: illegal numeric format.", buf);
+ val = strtonum(buf, 0, BIG, &errstr);
+ if (errstr)
+ errx(1, "start is %s: %s", errstr, buf);
return (val);
}
}
