date and time created 92/06/26 06:55:48 by bostic

SCCS-vsn: lib/libc/stdlib/strtoq.c 5.1

diff --git a/usr/src/lib/libc/stdlib/strtoq.c b/usr/src/lib/libc/stdlib/strtoq.c
new file mode 100644 (file)
index 0000000..56c928f
--- /dev/null
+++ b/usr/src/lib/libc/stdlib/strtoq.c
@@ -0,0 +1,110 @@
+/*-
+ * Copyright (c) 1992 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)strtoq.c   5.1 (Berkeley) %G%";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <limits.h>
+#include <errno.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+/*
+ * Convert a string to a quad integer.
+ *
+ * Ignores `locale' stuff.  Assumes that the upper and lower case
+ * alphabets and digits are each contiguous.
+ */
+quad_t
+strtoq(nptr, endptr, base)
+       const char *nptr;
+       char **endptr;
+       register int base;
+{
+       register const char *s;
+       register u_quad_t acc;
+       register int c;
+       register u_quad_t qbase, cutoff;
+       register int neg, any, cutlim;
+
+       /*
+        * Skip white space and pick up leading +/- sign if any.
+        * If base is 0, allow 0x for hex and 0 for octal, else
+        * assume decimal; if base is already 16, allow 0x.
+        */
+       s = nptr;
+       do {
+               c = *s++;
+       } while (isspace(c));
+       if (c == '-') {
+               neg = 1;
+               c = *s++;
+       } else {
+               neg = 0;
+               if (c == '+')
+                       c = *s++;
+       }
+       if ((base == 0 || base == 16) &&
+           c == '0' && (*s == 'x' || *s == 'X')) {
+               c = s[1];
+               s += 2;
+               base = 16;
+       }
+       if (base == 0)
+               base = c == '0' ? 8 : 10;
+
+       /*
+        * Compute the cutoff value between legal numbers and illegal
+        * numbers.  That is the largest legal value, divided by the
+        * base.  An input number that is greater than this value, if
+        * followed by a legal input character, is too big.  One that
+        * is equal to this value may be valid or not; the limit
+        * between valid and invalid numbers is then based on the last
+        * digit.  For instance, if the range for quads is
+        * [-9223372036854775808..9223372036854775807] and the input base
+        * is 10, cutoff will be set to 922337203685477580 and cutlim to
+        * either 7 (neg==0) or 8 (neg==1), meaning that if we have
+        * accumulated a value > 922337203685477580, or equal but the
+        * next digit is > 7 (or 8), the number is too big, and we will
+        * return a range error.
+        *
+        * Set any if any `digits' consumed; make it negative to indicate
+        * overflow.
+        */
+       qbase = (unsigned)base;
+       cutoff = neg ? -(u_quad_t)QUAD_MIN : QUAD_MAX;
+       cutlim = cutoff % qbase;
+       cutoff /= qbase;
+       for (acc = 0, any = 0;; c = *s++) {
+               if (isdigit(c))
+                       c -= '0';
+               else if (isalpha(c))
+                       c -= isupper(c) ? 'A' - 10 : 'a' - 10;
+               else
+                       break;
+               if (c >= base)
+                       break;
+               if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
+                       any = -1;
+               else {
+                       any = 1;
+                       acc *= qbase;
+                       acc += c;
+               }
+       }
+       if (any < 0) {
+               acc = neg ? QUAD_MIN : QUAD_MAX;
+               errno = ERANGE;
+       } else if (neg)
+               acc = -acc;
+       if (endptr != 0)
+               *endptr = any ? s - 1 : (char *)nptr;
+       return (acc);
+}