1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23 #include "curl_setup.h"
24
25 #include "strtoofft.h"
26
27 /*
28 * NOTE:
29 *
30 * In the ISO C standard (IEEE Std 1003.1), there is a strtoimax() function we
31 * could use in case strtoll() doesn't exist... See
32 * http://www.opengroup.org/onlinepubs/009695399/functions/strtoimax.html
33 */
34
35 #ifdef NEED_CURL_STRTOLL
36
37 /* Range tests can be used for alphanum decoding if characters are consecutive,
38 like in ASCII. Else an array is scanned. Determine this condition now. */
39
40 #if('9' - '0') != 9 || ('Z' - 'A') != 25 || ('z' - 'a') != 25
41
42 #define NO_RANGE_TEST
43
44 static const char valchars[] =
45 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
46 #endif
47
48 static int get_char(char c, int base);
49
50 /**
51 * Emulated version of the strtoll function. This extracts a long long
52 * value from the given input string and returns it.
53 */
54 curl_off_t
curlx_strtoll(const char * nptr,char ** endptr,int base)55 curlx_strtoll(const char *nptr, char **endptr, int base)
56 {
57 char *end;
58 int is_negative = 0;
59 int overflow;
60 int i;
61 curl_off_t value = 0;
62 curl_off_t newval;
63
64 /* Skip leading whitespace. */
65 end = (char *)nptr;
66 while(ISSPACE(end[0])) {
67 end++;
68 }
69
70 /* Handle the sign, if any. */
71 if(end[0] == '-') {
72 is_negative = 1;
73 end++;
74 }
75 else if(end[0] == '+') {
76 end++;
77 }
78 else if(end[0] == '\0') {
79 /* We had nothing but perhaps some whitespace -- there was no number. */
80 if(endptr) {
81 *endptr = end;
82 }
83 return 0;
84 }
85
86 /* Handle special beginnings, if present and allowed. */
87 if(end[0] == '0' && end[1] == 'x') {
88 if(base == 16 || base == 0) {
89 end += 2;
90 base = 16;
91 }
92 }
93 else if(end[0] == '0') {
94 if(base == 8 || base == 0) {
95 end++;
96 base = 8;
97 }
98 }
99
100 /* Matching strtol, if the base is 0 and it doesn't look like
101 * the number is octal or hex, we assume it's base 10.
102 */
103 if(base == 0) {
104 base = 10;
105 }
106
107 /* Loop handling digits. */
108 value = 0;
109 overflow = 0;
110 for(i = get_char(end[0], base);
111 i != -1;
112 end++, i = get_char(end[0], base)) {
113 newval = base * value + i;
114 if(newval < value) {
115 /* We've overflowed. */
116 overflow = 1;
117 break;
118 }
119 else
120 value = newval;
121 }
122
123 if(!overflow) {
124 if(is_negative) {
125 /* Fix the sign. */
126 value *= -1;
127 }
128 }
129 else {
130 if(is_negative)
131 value = CURL_OFF_T_MIN;
132 else
133 value = CURL_OFF_T_MAX;
134
135 SET_ERRNO(ERANGE);
136 }
137
138 if(endptr)
139 *endptr = end;
140
141 return value;
142 }
143
144 /**
145 * Returns the value of c in the given base, or -1 if c cannot
146 * be interpreted properly in that base (i.e., is out of range,
147 * is a null, etc.).
148 *
149 * @param c the character to interpret according to base
150 * @param base the base in which to interpret c
151 *
152 * @return the value of c in base, or -1 if c isn't in range
153 */
get_char(char c,int base)154 static int get_char(char c, int base)
155 {
156 #ifndef NO_RANGE_TEST
157 int value = -1;
158 if(c <= '9' && c >= '0') {
159 value = c - '0';
160 }
161 else if(c <= 'Z' && c >= 'A') {
162 value = c - 'A' + 10;
163 }
164 else if(c <= 'z' && c >= 'a') {
165 value = c - 'a' + 10;
166 }
167 #else
168 const char * cp;
169 int value;
170
171 cp = memchr(valchars, c, 10 + 26 + 26);
172
173 if(!cp)
174 return -1;
175
176 value = cp - valchars;
177
178 if(value >= 10 + 26)
179 value -= 26; /* Lowercase. */
180 #endif
181
182 if(value >= base) {
183 value = -1;
184 }
185
186 return value;
187 }
188 #endif /* Only present if we need strtoll, but don't have it. */
189