1 /* mpz_get_str (string, base, mp_src) -- Convert the multiple precision 2 number MP_SRC to a string STRING of base BASE. If STRING is NULL 3 allocate space for the result. In any case, return a pointer to the 4 result. If STRING is not NULL, the caller must ensure enough space is 5 available to store the result. 6 7 Copyright 1991, 1993, 1994, 1996, 2000, 2001, 2002, 2005 Free Software 8 Foundation, Inc. 9 10 This file is part of the GNU MP Library. 11 12 The GNU MP Library is free software; you can redistribute it and/or modify 13 it under the terms of the GNU Lesser General Public License as published by 14 the Free Software Foundation; either version 3 of the License, or (at your 15 option) any later version. 16 17 The GNU MP Library is distributed in the hope that it will be useful, but 18 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 19 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 20 License for more details. 21 22 You should have received a copy of the GNU Lesser General Public License 23 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 24 25 #include <string.h> /* for strlen */ 26 #include "gmp.h" 27 #include "gmp-impl.h" 28 #include "longlong.h" 29 30 char * 31 mpz_get_str (char *res_str, int base, mpz_srcptr x) 32 { 33 mp_ptr xp; 34 mp_size_t x_size = x->_mp_size; 35 char *str; 36 char *return_str; 37 size_t str_size; 38 size_t alloc_size = 0; 39 char *num_to_text; 40 int i; 41 TMP_DECL; 42 43 if (base >= 0) 44 { 45 num_to_text = "0123456789abcdefghijklmnopqrstuvwxyz"; 46 if (base == 0) 47 base = 10; 48 else if (base > 36) 49 { 50 num_to_text = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 51 if (base > 62) 52 return NULL; 53 } 54 } 55 else 56 { 57 base = -base; 58 num_to_text = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 59 } 60 61 /* allocate string for the user if necessary */ 62 if (res_str == NULL) 63 { 64 /* digits, null terminator, possible minus sign */ 65 MPN_SIZEINBASE (alloc_size, PTR(x), ABS(x_size), base); 66 alloc_size += 1 + (x_size<0); 67 res_str = (char *) (*__gmp_allocate_func) (alloc_size); 68 } 69 return_str = res_str; 70 71 if (x_size < 0) 72 { 73 *res_str++ = '-'; 74 x_size = -x_size; 75 } 76 77 /* mpn_get_str clobbers its input on non power-of-2 bases */ 78 TMP_MARK; 79 xp = x->_mp_d; 80 if (! POW2_P (base)) 81 { 82 xp = TMP_ALLOC_LIMBS (x_size + 1); /* +1 in case x_size==0 */ 83 MPN_COPY (xp, x->_mp_d, x_size); 84 } 85 86 str_size = mpn_get_str ((unsigned char *) res_str, base, xp, x_size); 87 ASSERT (alloc_size == 0 || str_size <= alloc_size - (SIZ(x) < 0)); 88 89 /* might have a leading zero, skip it */ 90 str = res_str; 91 if (*res_str == 0 && str_size != 1) 92 { 93 str_size--; 94 str++; 95 ASSERT (*str != 0); /* at most one leading zero */ 96 } 97 98 /* Convert result to printable chars, and move down if there was a leading 99 zero. */ 100 for (i = 0; i < str_size; i++) 101 res_str[i] = num_to_text[(int) str[i]]; 102 res_str[str_size] = 0; 103 104 TMP_FREE; 105 106 /* if allocated then resize down to the actual space required */ 107 if (alloc_size != 0) 108 { 109 size_t actual_size = str_size + 1 + (res_str - return_str); 110 ASSERT (actual_size == strlen (return_str) + 1); 111 __GMP_REALLOCATE_FUNC_MAYBE_TYPE (return_str, alloc_size, actual_size, 112 char); 113 } 114 return return_str; 115 } 116