1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)strtouq.c 8.1 (Berkeley) 06/04/93"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/types.h> 13 14 #include <limits.h> 15 #include <errno.h> 16 #include <ctype.h> 17 #include <stdlib.h> 18 19 /* 20 * Convert a string to an unsigned quad integer. 21 * 22 * Ignores `locale' stuff. Assumes that the upper and lower case 23 * alphabets and digits are each contiguous. 24 */ 25 u_quad_t 26 strtouq(nptr, endptr, base) 27 const char *nptr; 28 char **endptr; 29 register int base; 30 { 31 register const char *s = nptr; 32 register u_quad_t acc; 33 register int c; 34 register u_quad_t qbase, cutoff; 35 register int neg, any, cutlim; 36 37 /* 38 * See strtoq for comments as to the logic used. 39 */ 40 s = nptr; 41 do { 42 c = *s++; 43 } while (isspace(c)); 44 if (c == '-') { 45 neg = 1; 46 c = *s++; 47 } else { 48 neg = 0; 49 if (c == '+') 50 c = *s++; 51 } 52 if ((base == 0 || base == 16) && 53 c == '0' && (*s == 'x' || *s == 'X')) { 54 c = s[1]; 55 s += 2; 56 base = 16; 57 } 58 if (base == 0) 59 base = c == '0' ? 8 : 10; 60 qbase = (unsigned)base; 61 cutoff = (u_quad_t)UQUAD_MAX / qbase; 62 cutlim = (u_quad_t)UQUAD_MAX % qbase; 63 for (acc = 0, any = 0;; c = *s++) { 64 if (isdigit(c)) 65 c -= '0'; 66 else if (isalpha(c)) 67 c -= isupper(c) ? 'A' - 10 : 'a' - 10; 68 else 69 break; 70 if (c >= base) 71 break; 72 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim) 73 any = -1; 74 else { 75 any = 1; 76 acc *= qbase; 77 acc += c; 78 } 79 } 80 if (any < 0) { 81 acc = UQUAD_MAX; 82 errno = ERANGE; 83 } else if (neg) 84 acc = -acc; 85 if (endptr != 0) 86 *endptr = (char *)(any ? s - 1 : nptr); 87 return (acc); 88 } 89