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Commit	Line	Data
6a5fa4e0 MG	1	/*
	2	* strtoul.c --
	3	*
	4	* Source code for the "strtoul" library procedure.
	5	*
	6	* Copyright 1988 Regents of the University of California
	7	* Permission to use, copy, modify, and distribute this
	8	* software and its documentation for any purpose and without
	9	* fee is hereby granted, provided that the above copyright
	10	* notice appear in all copies. The University of California
	11	* makes no representations about the suitability of this
	12	* software for any purpose. It is provided "as is" without
	13	* express or implied warranty.
	14	*/
	15
	16	#ifndef lint
	17	static char rcsid[] = "$Header: /sprite/src/lib/tcl/compat/RCS/strtoul.c,v 1.2 91/09/22 14:04:43 ouster Exp $ SPRITE (Berkeley)";
	18	#endif /* not lint */
	19
	20	#include <ctype.h>
	21
	22	/*
	23	* The table below is used to convert from ASCII digits to a
	24	* numerical equivalent. It maps from '0' through 'z' to integers
	25	* (100 for non-digit characters).
	26	*/
	27
	28	static char cvtIn[] = {
	29	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* '0' - '9' */
	30	100, 100, 100, 100, 100, 100, 100, /* punctuation */
	31	10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'A' - 'Z' */
	32	20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
	33	30, 31, 32, 33, 34, 35,
	34	100, 100, 100, 100, 100, 100, /* punctuation */
	35	10, 11, 12, 13, 14, 15, 16, 17, 18, 19, /* 'a' - 'z' */
	36	20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
	37	30, 31, 32, 33, 34, 35};
	38	\f
	39	/*
	40	*----------------------------------------------------------------------
	41	*
	42	* strtoul --
	43	*
	44	* Convert an ASCII string into an integer.
	45	*
	46	* Results:
	47	* The return value is the integer equivalent of string. If endPtr
	48	* is non-NULL, then *endPtr is filled in with the character
	49	* after the last one that was part of the integer. If string
	50	* doesn't contain a valid integer value, then zero is returned
	51	* and *endPtr is set to string.
	52	*
	53	* Side effects:
	54	* None.
	55	*
	56	*----------------------------------------------------------------------
	57	*/
	58
	59	unsigned long int
	60	strtoul(string, endPtr, base)
	61	char string; / String of ASCII digits, possibly
	62	* preceded by white space. For bases
	63	* greater than 10, either lower- or
	64	* upper-case digits may be used.
65	*/
66	char *endPtr; / Where to store address of terminating
67	* character, or NULL. */
68	int base; /* Base for conversion. Must be less
69	* than 37. If 0, then the base is chosen
70	* from the leading characters of string:
71	* "0x" means hex, "0" means octal, anything
72	* else means decimal.
73	*/
74	{
75	register char *p;
76	register unsigned long int result = 0;
77	register unsigned digit;
78	int anyDigits = 0;
79
80	/*
81	* Skip any leading blanks.
82	*/
83
84	p = string;
85	while (isspace(*p)) {
86	p += 1;
87	}
88
89	/*
90	* If no base was provided, pick one from the leading characters
91	* of the string.
92	*/
93
94	if (base == 0)
95	{
96	if (*p == '0') {
97	p += 1;
98	if (*p == 'x') {
99	p += 1;
100	base = 16;
101	} else {
102
103	/*
104	* Must set anyDigits here, otherwise "0" produces a
105	* "no digits" error.
106	*/
107
108	anyDigits = 1;
109	base = 8;
110	}
111	}
112	else base = 10;
113	} else if (base == 16) {
114
115	/*
116	* Skip a leading "0x" from hex numbers.
117	*/
118
119	if ((p[0] == '0') && (p[1] == 'x')) {
120	p += 2;
121	}
122	}
123
124	/*
125	* Sorry this code is so messy, but speed seems important. Do
126	* different things for base 8, 10, 16, and other.
127	*/
128
129	if (base == 8) {
130	for ( ; ; p += 1) {
131	digit = *p - '0';
132	if (digit > 7) {
133	break;
134	}
135	result = (result << 3) + digit;
136	anyDigits = 1;
137	}
138	} else if (base == 10) {
139	for ( ; ; p += 1) {
140	digit = *p - '0';
141	if (digit > 9) {
142	break;
143	}
144	result = (10*result) + digit;
145	anyDigits = 1;
146	}
147	} else if (base == 16) {
148	for ( ; ; p += 1) {
149	digit = *p - '0';
150	if (digit > ('z' - '0')) {
151	break;
152	}
153	digit = cvtIn[digit];
154	if (digit > 15) {
155	break;
156	}
157	result = (result << 4) + digit;
158	anyDigits = 1;
159	}
160	} else {
161	for ( ; ; p += 1) {
162	digit = *p - '0';
163	if (digit > ('z' - '0')) {
164	break;
165	}
166	digit = cvtIn[digit];
167	if (digit >= base) {
168	break;
169	}
170	result = result*base + digit;
171	anyDigits = 1;
172	}
173	}
174
175	/*
176	* See if there were any digits at all.
177	*/
178
179	if (!anyDigits) {
180	p = string;
181	}
182
183	if (endPtr != 0) {
184	*endPtr = p;
185	}
186
187	return result;
188	}