1 /* mpz_inp_str(dest_integer, stream, base) -- Input a number in base
2 BASE from stdio stream STREAM and store the result in DEST_INTEGER.
3
4 OF THE FUNCTIONS IN THIS FILE, ONLY mpz_inp_str IS FOR EXTERNAL USE, THE
5 REST ARE INTERNALS AND ARE ALMOST CERTAIN TO BE SUBJECT TO INCOMPATIBLE
6 CHANGES OR DISAPPEAR COMPLETELY IN FUTURE GNU MP RELEASES.
7
8 Copyright 1991, 1993, 1994, 1996, 1998, 2000-2003, 2011-2013 Free Software
9 Foundation, Inc.
10
11 This file is part of the GNU MP Library.
12
13 The GNU MP Library is free software; you can redistribute it and/or modify
14 it under the terms of either:
15
16 * the GNU Lesser General Public License as published by the Free
17 Software Foundation; either version 3 of the License, or (at your
18 option) any later version.
19
20 or
21
22 * the GNU General Public License as published by the Free Software
23 Foundation; either version 2 of the License, or (at your option) any
24 later version.
25
26 or both in parallel, as here.
27
28 The GNU MP Library is distributed in the hope that it will be useful, but
29 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
30 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
31 for more details.
32
33 You should have received copies of the GNU General Public License and the
34 GNU Lesser General Public License along with the GNU MP Library. If not,
35 see https://www.gnu.org/licenses/. */
36
37 #include <stdio.h>
38 #include <ctype.h>
39 #include "gmp-impl.h"
40 #include "longlong.h"
41
42 #define digit_value_tab __gmp_digit_value_tab
43
44 size_t
45 mpz_inp_str (mpz_ptr x, FILE *stream, int base)
46 {
47 int c;
48 size_t nread;
49
50 if (stream == 0)
51 stream = stdin;
52
53 nread = 0;
54
55 /* Skip whitespace. */
56 do
57 {
58 c = getc (stream);
59 nread++;
60 }
61 while (isspace (c));
62
63 return mpz_inp_str_nowhite (x, stream, base, c, nread);
64 }
65
66 /* shared by mpq_inp_str */
67 size_t
68 mpz_inp_str_nowhite (mpz_ptr x, FILE *stream, int base, int c, size_t nread)
69 {
70 char *str;
71 size_t alloc_size, str_size;
72 int negative;
73 mp_size_t xsize;
74 const unsigned char *digit_value;
75
76 ASSERT_ALWAYS (EOF == -1); /* FIXME: handle this by adding explicit */
77 /* comparisons of c and EOF before each */
78 /* read of digit_value[]. */
79
80 digit_value = digit_value_tab;
81 if (base > 36)
82 {
83 /* For bases > 36, use the collating sequence
84 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz. */
85 digit_value += 208;
86 if (UNLIKELY (base > 62))
87 return 0; /* too large base */
88 }
89
90 negative = 0;
91 if (c == '-')
92 {
93 negative = 1;
94 c = getc (stream);
95 nread++;
96 }
97
98 if (c == EOF || digit_value[c] >= (base == 0 ? 10 : base))
99 return 0; /* error if no digits */
100
101 /* If BASE is 0, try to find out the base by looking at the initial
102 characters. */
103 if (base == 0)
104 {
105 base = 10;
106 if (c == '0')
107 {
108 base = 8;
109 c = getc (stream);
110 nread++;
111 if (c == 'x' || c == 'X')
112 {
113 base = 16;
114 c = getc (stream);
115 nread++;
116 }
117 else if (c == 'b' || c == 'B')
118 {
119 base = 2;
120 c = getc (stream);
121 nread++;
122 }
123 }
124 }
125
126 /* Skip leading zeros. */
127 while (c == '0')
128 {
129 c = getc (stream);
130 nread++;
131 }
132
133 alloc_size = 100;
134 str = __GMP_ALLOCATE_FUNC_TYPE (alloc_size, char);
135 str_size = 0;
136
137 while (c != EOF)
138 {
139 int dig;
140 dig = digit_value[c];
141 if (dig >= base)
142 break;
143 if (str_size >= alloc_size)
144 {
145 size_t old_alloc_size = alloc_size;
146 alloc_size = alloc_size * 3 / 2;
147 str = __GMP_REALLOCATE_FUNC_TYPE (str, old_alloc_size, alloc_size, char);
148 }
149 str[str_size++] = dig;
150 c = getc (stream);
151 }
152 nread += str_size;
153
154 ungetc (c, stream);
155 nread--;
156
157 /* Make sure the string is not empty, mpn_set_str would fail. */
158 if (str_size == 0)
159 {
160 SIZ (x) = 0;
161 }
162 else
163 {
164 LIMBS_PER_DIGIT_IN_BASE (xsize, str_size, base);
165 MPZ_NEWALLOC (x, xsize);
166
167 /* Convert the byte array in base BASE to our bignum format. */
168 xsize = mpn_set_str (PTR (x), (unsigned char *) str, str_size, base);
169 SIZ (x) = negative ? -xsize : xsize;
170 }
171 (*__gmp_free_func) (str, alloc_size);
172 return nread;
173 }