| [9] | 1 | /*
|
|---|
| 2 | * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
|
|---|
| 3 | * See the copyright notice in the ACK home directory, in the file "Copyright".
|
|---|
| 4 | */
|
|---|
| 5 | /* $Header: /cvsup/minix/src/lib/ansi/strtol.c,v 1.1.1.1 2005/04/21 14:56:06 beng Exp $ */
|
|---|
| 6 |
|
|---|
| 7 | #include <ctype.h>
|
|---|
| 8 | #include <errno.h>
|
|---|
| 9 | #include <limits.h>
|
|---|
| 10 | #include <stdlib.h>
|
|---|
| 11 |
|
|---|
| 12 | static unsigned long
|
|---|
| 13 | string2long(register const char *nptr, char **endptr,
|
|---|
| 14 | int base, int is_signed);
|
|---|
| 15 |
|
|---|
| 16 | long int
|
|---|
| 17 | strtol(register const char *nptr, char **endptr, int base)
|
|---|
| 18 | {
|
|---|
| 19 | return (signed long)string2long(nptr, endptr, base, 1);
|
|---|
| 20 | }
|
|---|
| 21 |
|
|---|
| 22 | unsigned long int
|
|---|
| 23 | strtoul(register const char *nptr, char **endptr, int base)
|
|---|
| 24 | {
|
|---|
| 25 | return (unsigned long)string2long(nptr, endptr, base, 0);
|
|---|
| 26 | }
|
|---|
| 27 |
|
|---|
| 28 | #define between(a, c, z) ((unsigned) ((c) - (a)) <= (unsigned) ((z) - (a)))
|
|---|
| 29 |
|
|---|
| 30 | static unsigned long
|
|---|
| 31 | string2long(register const char *nptr, char ** const endptr,
|
|---|
| 32 | int base, int is_signed)
|
|---|
| 33 | {
|
|---|
| 34 | register unsigned int v;
|
|---|
| 35 | register unsigned long val = 0;
|
|---|
| 36 | register int c;
|
|---|
| 37 | int ovfl = 0, sign = 1;
|
|---|
| 38 | const char *startnptr = nptr, *nrstart;
|
|---|
| 39 |
|
|---|
| 40 | if (endptr) *endptr = (char *)nptr;
|
|---|
| 41 | while (isspace(*nptr)) nptr++;
|
|---|
| 42 | c = *nptr;
|
|---|
| 43 |
|
|---|
| 44 | if (c == '-' || c == '+') {
|
|---|
| 45 | if (c == '-') sign = -1;
|
|---|
| 46 | nptr++;
|
|---|
| 47 | }
|
|---|
| 48 | nrstart = nptr; /* start of the number */
|
|---|
| 49 |
|
|---|
| 50 | /* When base is 0, the syntax determines the actual base */
|
|---|
| 51 | if (base == 0)
|
|---|
| 52 | if (*nptr == '0')
|
|---|
| 53 | if (*++nptr == 'x' || *nptr == 'X') {
|
|---|
| 54 | base = 16;
|
|---|
| 55 | nptr++;
|
|---|
| 56 | }
|
|---|
| 57 | else base = 8;
|
|---|
| 58 | else base = 10;
|
|---|
| 59 | else if (base==16 && *nptr=='0' && (*++nptr =='x' || *nptr =='X'))
|
|---|
| 60 | nptr++;
|
|---|
| 61 |
|
|---|
| 62 | for (;;) {
|
|---|
| 63 | c = *nptr;
|
|---|
| 64 | if (between('0', c, '9')) {
|
|---|
| 65 | v = c - '0';
|
|---|
| 66 | } else
|
|---|
| 67 | if (between('a', c, 'z')) {
|
|---|
| 68 | v = c - 'a' + 0xa;
|
|---|
| 69 | } else
|
|---|
| 70 | if (between('A', c, 'Z')) {
|
|---|
| 71 | v = c - 'A' + 0xA;
|
|---|
| 72 | } else {
|
|---|
| 73 | break;
|
|---|
| 74 | }
|
|---|
| 75 | if (v >= base) break;
|
|---|
| 76 | if (val > (ULONG_MAX - v) / base) ovfl++;
|
|---|
| 77 | val = (val * base) + v;
|
|---|
| 78 | nptr++;
|
|---|
| 79 | }
|
|---|
| 80 | if (endptr) {
|
|---|
| 81 | if (nrstart == nptr) *endptr = (char *)startnptr;
|
|---|
| 82 | else *endptr = (char *)nptr;
|
|---|
| 83 | }
|
|---|
| 84 |
|
|---|
| 85 | if (!ovfl) {
|
|---|
| 86 | /* Overflow is only possible when converting a signed long. */
|
|---|
| 87 | if (is_signed
|
|---|
| 88 | && ( (sign < 0 && val > -(unsigned long)LONG_MIN)
|
|---|
| 89 | || (sign > 0 && val > LONG_MAX)))
|
|---|
| 90 | ovfl++;
|
|---|
| 91 | }
|
|---|
| 92 |
|
|---|
| 93 | if (ovfl) {
|
|---|
| 94 | errno = ERANGE;
|
|---|
| 95 | if (is_signed)
|
|---|
| 96 | if (sign < 0) return LONG_MIN;
|
|---|
| 97 | else return LONG_MAX;
|
|---|
| 98 | else return ULONG_MAX;
|
|---|
| 99 | }
|
|---|
| 100 | return (long) sign * val;
|
|---|
| 101 | }
|
|---|
