net-snmp 5.7
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00001 /* 00002 * Copyright (c) 1990 The Regents of the University of California. 00003 * All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without 00006 * modification, are permitted provided that the following conditions 00007 * are met: 00008 * 1. Redistributions of source code must retain the above copyright 00009 * notice, this list of conditions and the following disclaimer. 00010 * 2. Redistributions in binary form must reproduce the above copyright 00011 * notice, this list of conditions and the following disclaimer in the 00012 * documentation and/or other materials provided with the distribution. 00013 * 3. Neither the name of the University nor the names of its contributors 00014 * may be used to endorse or promote products derived from this software 00015 * without specific prior written permission. 00016 * 00017 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 00018 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00019 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00020 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 00021 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00022 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 00023 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 00024 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00025 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 00026 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00027 * SUCH DAMAGE. 00028 */ 00029 00030 #include <net-snmp/net-snmp-config.h> 00031 00032 #if defined(LIBC_SCCS) && !defined(lint) 00033 static char sccsid[] = "@(#)strtol.c 5.4 (Berkeley) 2/23/91"; 00034 #endif /* LIBC_SCCS and not lint */ 00035 00036 #if HAVE_LIMITS_H 00037 #include <limits.h> 00038 #endif 00039 #include <ctype.h> 00040 #include <errno.h> 00041 #if HAVE_STDLIB_H 00042 #include <stdlib.h> 00043 #endif 00044 00045 /* 00046 * Convert a string to a long integer. 00047 * 00048 * Ignores `locale' stuff. Assumes that the upper and lower case 00049 * alphabets and digits are each contiguous. 00050 */ 00051 long 00052 strtol(const char *nptr, char **endptr, int base) 00053 { 00054 const char *s = nptr; 00055 unsigned long acc; 00056 int c; 00057 unsigned long cutoff; 00058 int neg = 0, any, cutlim; 00059 00060 /* 00061 * Skip white space and pick up leading +/- sign if any. If base is 0, 00062 * allow 0x for hex and 0 for octal, else assume decimal; if base is 00063 * already 16, allow 0x. 00064 */ 00065 do { 00066 c = *s++; 00067 } while (isspace(c)); 00068 if (c == '-') { 00069 neg = 1; 00070 c = *s++; 00071 } else if (c == '+') 00072 c = *s++; 00073 if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) { 00074 c = s[1]; 00075 s += 2; 00076 base = 16; 00077 } 00078 if (base == 0) 00079 base = c == '0' ? 8 : 10; 00080 00081 /* 00082 * Compute the cutoff value between legal numbers and illegal numbers. 00083 * That is the largest legal value, divided by the base. An input 00084 * number that is greater than this value, if followed by a legal 00085 * input character, is too big. One that is equal to this value may 00086 * be valid or not; the limit between valid and invalid numbers is 00087 * then based on the last digit. For instance, if the range for longs 00088 * is [-2147483648..2147483647] and the input base is 10, cutoff will 00089 * be set to 214748364 and cutlim to either 7 (neg==0) or 8 (neg==1), 00090 * meaning that if we have accumulated a value > 214748364, or equal 00091 * but the next digit is > 7 (or 8), the number is too big, and we 00092 * will return a range error. 00093 * 00094 * Set any if any `digits' consumed; make it negative to indicate 00095 * overflow. 00096 */ 00097 cutoff = neg ? -(unsigned long) LONG_MIN : LONG_MAX; 00098 cutlim = cutoff % (unsigned long) base; 00099 cutoff /= (unsigned long) base; 00100 for (acc = 0, any = 0;; c = *s++) { 00101 if (isdigit(c)) 00102 c -= '0'; 00103 else if (isalpha(c)) 00104 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 00105 else 00106 break; 00107 if (c >= base) 00108 break; 00109 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 00110 any = -1; 00111 else { 00112 any = 1; 00113 acc *= base; 00114 acc += c; 00115 } 00116 } 00117 if (any < 0) { 00118 acc = neg ? LONG_MIN : LONG_MAX; 00119 errno = ERANGE; 00120 } else if (neg) 00121 acc = -acc; 00122 if (endptr != 0) 00123 *endptr = any ? s - 1 : (char *) nptr; 00124 return (acc); 00125 }