/*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 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. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93"; #endif /* LIBC_SCCS and not lint */ #include <sys/cdefs.h> __FBSDID("$FreeBSD: src/lib/libc/stdlib/strtol.c,v 1.17 2002/09/06 11:23:59 tjr Exp $"); #include <limits.h> #include <ctype.h> #include <errno.h> #include <stdlib.h> /* * Convert a string to a long integer. * * Assumes that the upper and lower case * alphabets and digits are each contiguous. */ long strtol(const char * __restrict nptr, char ** __restrict endptr, int base) { const char *s; unsigned long acc; char c; unsigned long 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((unsigned char)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; acc = any = 0; if (base < 2 || base > 36) goto noconv; /* * 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 longs is * [-2147483648..2147483647] and the input base is 10, * cutoff will be set to 214748364 and cutlim to either * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated * a value > 214748364, 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. */ cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX : LONG_MAX; cutlim = cutoff % base; cutoff /= base; for ( ; ; c = *s++) { if (c >= '0' && c <= '9') c -= '0'; else if (c >= 'A' && c <= 'Z') c -= 'A' - 10; else if (c >= 'a' && c <= 'z') c -= 'a' - 10; else break; if (c >= base) break; if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) any = -1; else { any = 1; acc *= base; acc += c; } } if (any < 0) { acc = neg ? LONG_MIN : LONG_MAX; errno = ERANGE; } else if (!any) { noconv: errno = EINVAL; } else if (neg) acc = -acc; if (endptr != NULL) *endptr = (char *)(any ? s - 1 : nptr); return (acc); }