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| 2 | pj | 1 | /*- |
| 2 | * Copyright (c) 1990, 1993 |
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| 3 | * The Regents of the University of California. All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * 1. Redistributions of source code must retain the above copyright |
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| 9 | * notice, this list of conditions and the following disclaimer. |
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| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer in the |
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| 12 | * documentation and/or other materials provided with the distribution. |
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| 13 | * 3. All advertising materials mentioning features or use of this software |
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| 14 | * must display the following acknowledgement: |
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| 15 | * This product includes software developed by the University of |
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| 16 | * California, Berkeley and its contributors. |
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| 17 | * 4. Neither the name of the University nor the names of its contributors |
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| 18 | * may be used to endorse or promote products derived from this software |
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| 19 | * without specific prior written permission. |
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| 20 | * |
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| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 31 | * SUCH DAMAGE. |
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| 32 | */ |
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| 33 | |||
| 34 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 35 | static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93"; |
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| 36 | #endif /* LIBC_SCCS and not lint */ |
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| 37 | |||
| 38 | #include <limits.h> |
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| 39 | #include <ctype.h> |
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| 40 | #include <errno.h> |
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| 41 | #include <stdlib.h> |
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| 42 | |||
| 43 | |||
| 44 | /* |
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| 45 | * Convert a string to a long integer. |
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| 46 | * |
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| 47 | * Ignores `locale' stuff. Assumes that the upper and lower case |
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| 48 | * alphabets and digits are each contiguous. |
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| 49 | */ |
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| 50 | long |
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| 51 | strtol(nptr, endptr, base) |
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| 52 | const char *nptr; |
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| 53 | char **endptr; |
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| 54 | register int base; |
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| 55 | { |
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| 56 | register const char *s = nptr; |
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| 57 | register unsigned long acc; |
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| 58 | register unsigned char c; |
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| 59 | register unsigned long cutoff; |
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| 60 | register int neg = 0, any, cutlim; |
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| 61 | |||
| 62 | /* |
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| 63 | * Skip white space and pick up leading +/- sign if any. |
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| 64 | * If base is 0, allow 0x for hex and 0 for octal, else |
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| 65 | * assume decimal; if base is already 16, allow 0x. |
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| 66 | */ |
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| 67 | do { |
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| 68 | c = *s++; |
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| 69 | } while (isspace(c)); |
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| 70 | if (c == '-') { |
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| 71 | neg = 1; |
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| 72 | c = *s++; |
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| 73 | } else if (c == '+') |
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| 74 | c = *s++; |
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| 75 | if ((base == 0 || base == 16) && |
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| 76 | c == '0' && (*s == 'x' || *s == 'X')) { |
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| 77 | c = s[1]; |
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| 78 | s += 2; |
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| 79 | base = 16; |
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| 80 | } |
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| 81 | if (base == 0) |
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| 82 | base = c == '0' ? 8 : 10; |
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| 83 | |||
| 84 | /* |
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| 85 | * Compute the cutoff value between legal numbers and illegal |
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| 86 | * numbers. That is the largest legal value, divided by the |
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| 87 | * base. An input number that is greater than this value, if |
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| 88 | * followed by a legal input character, is too big. One that |
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| 89 | * is equal to this value may be valid or not; the limit |
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| 90 | * between valid and invalid numbers is then based on the last |
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| 91 | * digit. For instance, if the range for longs is |
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| 92 | * [-2147483648..2147483647] and the input base is 10, |
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| 93 | * cutoff will be set to 214748364 and cutlim to either |
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| 94 | * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated |
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| 95 | * a value > 214748364, or equal but the next digit is > 7 (or 8), |
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| 96 | * the number is too big, and we will return a range error. |
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| 97 | * |
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| 98 | * Set any if any `digits' consumed; make it negative to indicate |
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| 99 | * overflow. |
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| 100 | */ |
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| 101 | cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; |
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| 102 | cutlim = cutoff % (unsigned long)base; |
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| 103 | cutoff /= (unsigned long)base; |
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| 104 | for (acc = 0, any = 0;; c = *s++) { |
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| 105 | if (!isascii(c)) |
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| 106 | break; |
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| 107 | if (isdigit(c)) |
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| 108 | c -= '0'; |
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| 109 | else if (isalpha(c)) |
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| 110 | c -= isupper(c) ? 'A' - 10 : 'a' - 10; |
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| 111 | else |
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| 112 | break; |
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| 113 | if (c >= base) |
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| 114 | break; |
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| 115 | if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) |
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| 116 | any = -1; |
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| 117 | else { |
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| 118 | any = 1; |
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| 119 | acc *= base; |
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| 120 | acc += c; |
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| 121 | } |
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| 122 | } |
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| 123 | if (any < 0) { |
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| 124 | acc = neg ? LONG_MIN : LONG_MAX; |
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| 125 | errno = ERANGE; |
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| 126 | } else if (neg) |
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| 127 | acc = -acc; |
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| 128 | if (endptr != 0) |
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| 129 | *endptr = (char *)(any ? s - 1 : nptr); |
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| 130 | return (acc); |
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| 131 | } |