Current Path : /sys/libkern/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/libkern/strtoq.c |
/*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/libkern/strtoq.c 128019 2004-04-07 20:46:16Z imp $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/ctype.h> #include <sys/limits.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(const char *nptr, char **endptr, int base) { const char *s; u_quad_t acc; unsigned char c; u_quad_t qbase, cutoff; 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) + QUAD_MAX : QUAD_MAX; cutlim = cutoff % qbase; cutoff /= qbase; for (acc = 0, any = 0;; c = *s++) { if (!isascii(c)) break; 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; } else if (neg) acc = -acc; if (endptr != 0) *((const char **)endptr) = any ? s - 1 : nptr; return (acc); }