1*54495Sbostic /*- 2*54495Sbostic * Copyright (c) 1992 The Regents of the University of California. 3*54495Sbostic * All rights reserved. 4*54495Sbostic * 5*54495Sbostic * %sccs.include.redist.c% 6*54495Sbostic */ 7*54495Sbostic 8*54495Sbostic #if defined(LIBC_SCCS) && !defined(lint) 9*54495Sbostic static char sccsid[] = "@(#)strtoq.c 5.1 (Berkeley) 06/26/92"; 10*54495Sbostic #endif /* LIBC_SCCS and not lint */ 11*54495Sbostic 12*54495Sbostic #include <sys/types.h> 13*54495Sbostic 14*54495Sbostic #include <limits.h> 15*54495Sbostic #include <errno.h> 16*54495Sbostic #include <ctype.h> 17*54495Sbostic #include <stdlib.h> 18*54495Sbostic 19*54495Sbostic /* 20*54495Sbostic * Convert a string to a quad integer. 21*54495Sbostic * 22*54495Sbostic * Ignores `locale' stuff. Assumes that the upper and lower case 23*54495Sbostic * alphabets and digits are each contiguous. 24*54495Sbostic */ 25*54495Sbostic quad_t 26*54495Sbostic strtoq(nptr, endptr, base) 27*54495Sbostic const char *nptr; 28*54495Sbostic char **endptr; 29*54495Sbostic register int base; 30*54495Sbostic { 31*54495Sbostic register const char *s; 32*54495Sbostic register u_quad_t acc; 33*54495Sbostic register int c; 34*54495Sbostic register u_quad_t qbase, cutoff; 35*54495Sbostic register int neg, any, cutlim; 36*54495Sbostic 37*54495Sbostic /* 38*54495Sbostic * Skip white space and pick up leading +/- sign if any. 39*54495Sbostic * If base is 0, allow 0x for hex and 0 for octal, else 40*54495Sbostic * assume decimal; if base is already 16, allow 0x. 41*54495Sbostic */ 42*54495Sbostic s = nptr; 43*54495Sbostic do { 44*54495Sbostic c = *s++; 45*54495Sbostic } while (isspace(c)); 46*54495Sbostic if (c == '-') { 47*54495Sbostic neg = 1; 48*54495Sbostic c = *s++; 49*54495Sbostic } else { 50*54495Sbostic neg = 0; 51*54495Sbostic if (c == '+') 52*54495Sbostic c = *s++; 53*54495Sbostic } 54*54495Sbostic if ((base == 0 || base == 16) && 55*54495Sbostic c == '0' && (*s == 'x' || *s == 'X')) { 56*54495Sbostic c = s[1]; 57*54495Sbostic s += 2; 58*54495Sbostic base = 16; 59*54495Sbostic } 60*54495Sbostic if (base == 0) 61*54495Sbostic base = c == '0' ? 8 : 10; 62*54495Sbostic 63*54495Sbostic /* 64*54495Sbostic * Compute the cutoff value between legal numbers and illegal 65*54495Sbostic * numbers. That is the largest legal value, divided by the 66*54495Sbostic * base. An input number that is greater than this value, if 67*54495Sbostic * followed by a legal input character, is too big. One that 68*54495Sbostic * is equal to this value may be valid or not; the limit 69*54495Sbostic * between valid and invalid numbers is then based on the last 70*54495Sbostic * digit. For instance, if the range for quads is 71*54495Sbostic * [-9223372036854775808..9223372036854775807] and the input base 72*54495Sbostic * is 10, cutoff will be set to 922337203685477580 and cutlim to 73*54495Sbostic * either 7 (neg==0) or 8 (neg==1), meaning that if we have 74*54495Sbostic * accumulated a value > 922337203685477580, or equal but the 75*54495Sbostic * next digit is > 7 (or 8), the number is too big, and we will 76*54495Sbostic * return a range error. 77*54495Sbostic * 78*54495Sbostic * Set any if any `digits' consumed; make it negative to indicate 79*54495Sbostic * overflow. 80*54495Sbostic */ 81*54495Sbostic qbase = (unsigned)base; 82*54495Sbostic cutoff = neg ? -(u_quad_t)QUAD_MIN : QUAD_MAX; 83*54495Sbostic cutlim = cutoff % qbase; 84*54495Sbostic cutoff /= qbase; 85*54495Sbostic for (acc = 0, any = 0;; c = *s++) { 86*54495Sbostic if (isdigit(c)) 87*54495Sbostic c -= '0'; 88*54495Sbostic else if (isalpha(c)) 89*54495Sbostic c -= isupper(c) ? 'A' - 10 : 'a' - 10; 90*54495Sbostic else 91*54495Sbostic break; 92*54495Sbostic if (c >= base) 93*54495Sbostic break; 94*54495Sbostic if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 95*54495Sbostic any = -1; 96*54495Sbostic else { 97*54495Sbostic any = 1; 98*54495Sbostic acc *= qbase; 99*54495Sbostic acc += c; 100*54495Sbostic } 101*54495Sbostic } 102*54495Sbostic if (any < 0) { 103*54495Sbostic acc = neg ? QUAD_MIN : QUAD_MAX; 104*54495Sbostic errno = ERANGE; 105*54495Sbostic } else if (neg) 106*54495Sbostic acc = -acc; 107*54495Sbostic if (endptr != 0) 108*54495Sbostic *endptr = any ? s - 1 : (char *)nptr; 109*54495Sbostic return (acc); 110*54495Sbostic } 111