diff options
Diffstat (limited to 'lib/libc/stdlib/strtoimax.c')
| -rw-r--r-- | lib/libc/stdlib/strtoimax.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/lib/libc/stdlib/strtoimax.c b/lib/libc/stdlib/strtoimax.c new file mode 100644 index 0000000..f8ff09b --- /dev/null +++ b/lib/libc/stdlib/strtoimax.c @@ -0,0 +1,142 @@ +/*- + * Copyright (c) 1992, 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. + * + * $FreeBSD$ + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "from @(#)strtol.c 8.1 (Berkeley) 6/4/93"; +#endif /* LIBC_SCCS and not lint */ + +#include <ctype.h> +#include <errno.h> +#include <stdlib.h> +#include <inttypes.h> + +/* + * Convert a string to a intmax_t integer. + * + * Assumes that the upper and lower case + * alphabets and digits are each contiguous. + */ +intmax_t +strtoimax(nptr, endptr, base) + const char *nptr; + char **endptr; + int base; +{ + const char *s; + uintmax_t acc; + unsigned char c; + uintmax_t 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(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 intmax_t is + * [-9223372036854775808..9223372036854775807] and the input base + * is 10, cutoff will be set to 922337203685477580 and cutlim to + * either 7 (neg==0) or 8 (neg==1), meaning that if we have + * accumulated a value > 922337203685477580, 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 ? (uintmax_t)-(INTMAX_MIN + INTMAX_MAX) + INTMAX_MAX + : INTMAX_MAX; + cutlim = cutoff % base; + cutoff /= base; + for ( ; ; c = *s++) { + if (isxdigit(c)) + c = digittoint(c); + else if (isascii(c) && isalpha(c)) + c -= isupper(c) ? 'A' - 10 : '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 ? INTMAX_MIN : INTMAX_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); +} |
