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Diffstat (limited to 'compat/strtoul.c')
| -rw-r--r-- | compat/strtoul.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/compat/strtoul.c b/compat/strtoul.c new file mode 100644 index 0000000..9d3f372 --- /dev/null +++ b/compat/strtoul.c @@ -0,0 +1,214 @@ +/* + * strtoul.c -- + * + * Source code for the "strtoul" library procedure. + * + * Copyright (c) 1988 The Regents of the University of California. + * Copyright (c) 1994 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution of + * this file, and for a DISCLAIMER OF ALL WARRANTIES. + */ + +#include "tclInt.h" + +/* + * The table below is used to convert from ASCII digits to a numerical + * equivalent. It maps from '0' through 'z' to integers (100 for non-digit + * characters). + */ + +static char cvtIn[] = { + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* '0' - '9' */ + 100, 100, 100, 100, 100, 100, 100, /* punctuation */ + 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'A' - 'Z' */ + 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, + 30, 31, 32, 33, 34, 35, + 100, 100, 100, 100, 100, 100, /* punctuation */ + 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'a' - 'z' */ + 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, + 30, 31, 32, 33, 34, 35}; + +/* + *---------------------------------------------------------------------- + * + * strtoul -- + * + * Convert an ASCII string into an integer. + * + * Results: + * The return value is the integer equivalent of string. If endPtr is + * non-NULL, then *endPtr is filled in with the character after the last + * one that was part of the integer. If string doesn't contain a valid + * integer value, then zero is returned and *endPtr is set to string. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +unsigned long int +strtoul( + CONST char *string, /* String of ASCII digits, possibly preceded + * by white space. For bases greater than 10, + * either lower- or upper-case digits may be + * used. */ + char **endPtr, /* Where to store address of terminating + * character, or NULL. */ + int base) /* Base for conversion. Must be less than 37. + * If 0, then the base is chosen from the + * leading characters of string: "0x" means + * hex, "0" means octal, anything else means + * decimal. */ +{ + register CONST char *p; + register unsigned long int result = 0; + register unsigned digit; + int anyDigits = 0; + int negative=0; + int overflow=0; + + /* + * Skip any leading blanks. + */ + + p = string; + while (isspace(UCHAR(*p))) { + p += 1; + } + if (*p == '-') { + negative = 1; + p += 1; + } else { + if (*p == '+') { + p += 1; + } + } + + /* + * If no base was provided, pick one from the leading characters of the + * string. + */ + + if (base == 0) { + if (*p == '0') { + p += 1; + if ((*p == 'x') || (*p == 'X')) { + p += 1; + base = 16; + } else { + /* + * Must set anyDigits here, otherwise "0" produces a "no + * digits" error. + */ + + anyDigits = 1; + base = 8; + } + } else { + base = 10; + } + } else if (base == 16) { + /* + * Skip a leading "0x" from hex numbers. + */ + + if ((p[0] == '0') && ((p[1] == 'x') || (p[1] == 'X'))) { + p += 2; + } + } + + /* + * Sorry this code is so messy, but speed seems important. Do different + * things for base 8, 10, 16, and other. + */ + + if (base == 8) { + unsigned long maxres = ULONG_MAX >> 3; + + for ( ; ; p += 1) { + digit = *p - '0'; + if (digit > 7) { + break; + } + if (result > maxres) { overflow = 1; } + result = (result << 3); + if (digit > (ULONG_MAX - result)) { overflow = 1; } + result += digit; + anyDigits = 1; + } + } else if (base == 10) { + unsigned long maxres = ULONG_MAX / 10; + + for ( ; ; p += 1) { + digit = *p - '0'; + if (digit > 9) { + break; + } + if (result > maxres) { overflow = 1; } + result *= 10; + if (digit > (ULONG_MAX - result)) { overflow = 1; } + result += digit; + anyDigits = 1; + } + } else if (base == 16) { + unsigned long maxres = ULONG_MAX >> 4; + + for ( ; ; p += 1) { + digit = *p - '0'; + if (digit > ('z' - '0')) { + break; + } + digit = cvtIn[digit]; + if (digit > 15) { + break; + } + if (result > maxres) { overflow = 1; } + result = (result << 4); + if (digit > (ULONG_MAX - result)) { overflow = 1; } + result += digit; + anyDigits = 1; + } + } else if (base >= 2 && base <= 36) { + unsigned long maxres = ULONG_MAX / base; + + for ( ; ; p += 1) { + digit = *p - '0'; + if (digit > ('z' - '0')) { + break; + } + digit = cvtIn[digit]; + if (digit >= ( (unsigned) base )) { + break; + } + if (result > maxres) { overflow = 1; } + result *= base; + if (digit > (ULONG_MAX - result)) { overflow = 1; } + result += digit; + anyDigits = 1; + } + } + + /* + * See if there were any digits at all. + */ + + if (!anyDigits) { + p = string; + } + + if (endPtr != 0) { + /* unsafe, but required by the strtoul prototype */ + *endPtr = (char *) p; + } + + if (overflow) { + errno = ERANGE; + return ULONG_MAX; + } + if (negative) { + return -result; + } + return result; +} |