如何将16进制字符串转换成10进制？

kennhh

我现在碰到一个很棘手的问题，我想把一个8位的16进制字符串转换成10位的10进制字符串，用strtol函数时发现只要16进制字符串大于7FFFFFFF以后，转换后的值就都变成了2147483647

例如：要转换95A7B387成10进制，正确的值应该是2510795655，可用strtol转换的结果却是2147483647

我已经查出这是由于long型的取值范围的局限，改用strtoul函数时发现结果的值是-1784171641

请问，有高人知道如何才能解决这样的问题？？？？

万分感谢！

lenovo

用strtoull或strtoll。

kennhh

我是hp－unix环境，好像没有strtoull和strtoll这样的函数吧？

lenovo

你man strtol试试。
我的是aix5l，也man不到它们两个，
不过man strtol就可以看到它们两个。

kennhh

好像还是看不到啊，lenovo，你能介绍一下strtoll或strtoull的用法吗？

非常感谢！

lenovo

1. 
   
2. #include <stdlib.h>;
   
3. 
   
4. long strtol ( String, EndPointer, Base)
   
5. 
   
6. const char *String;
   
7. 
   
8. char **EndPointer;
   
9. 
   
10. int Base;
    
11. 
    
12. unsigned long strtoul (String, EndPointer, Base)
    
13. 
    
14. const char *String;
    
15. 
    
16. char **EndPointer;
    
17. 
    
18. int Base;
    
19. 
    
20. extern long long int strtoll (String, EndPointer, Base)
    
21. 
    
22. char *String, **EndPointer;
    
23. 
    
24. int Base;
    
25. 
    
26. extern long long int strtoull (String, EndPointer, Base)
    
27. 
    
28. char *String, **EndPointer;
    
29. 
    
30. int Base;
    
31. 
    
32. long atol (String)
    
33. 
    
34. const char *String;
    
35. 
    
36. int atoi (String)
    
37. 
    
38. const char *String;
    
39. 
    
40. Description
    
41. 
    
42. The strtol subroutine returns a long integer whose value is represented by the
    
43. character string to which the String parameter points. The strtol subroutine
    
44. scans the string up to the first character that is inconsistent with the Base
    
45. parameter. Leading white-space characters are ignored, and an optional sign may
    
46. precede the digits.
    
47. 
    
48. The strtoul subroutine provides the same functions but returns an unsigned long
    
49. integer.
    
50. 
    
51. The strtoll and strtoull subroutines provide the same functions but return long
    
52. long integers.
    
53. 
    
54. The atol subroutine is equivalent to the strtol subroutine where the value of
    
55. the EndPointer parameter is a null pointer and the Base parameter is a value of
    
56. 10.
    
57. 
    
58. The atoi subroutine is equivalent to the strtol subroutine where the value of
    
59. the EndPointer parameter is a null pointer and the Base parameter is a value of
    
60. 10.
    
61. 
    
62. If the value of the EndPointer parameter is not null, then a pointer to the
    
63. character that ended the scan is stored in EndPointer. If an integer cannot be
    
64. formed, the value of the EndPointer parameter is set to that of the String
    
65. parameter.
    
66. 
    
67. If the Base parameter is a value between 2 and 36, the subject sequence's
    
68. expected form is a sequence of letters and digits representing an integer whose
    
69. radix is specified by the Base parameter. This sequence is optionally preceded
    
70. by a + (positive) or - (negative) sign. Letters from a (or A) to z (or Z)
    
71. inclusive are ascribed the values 10 to 35; only letters whose ascribed values
    
72. are less than that of the Base parameter are permitted. If the Base parameter
    
73. has a value of 16, the characters 0x or 0X optionally precede the sequence of
    
74. letters and digits, following the + (positive) or - (negative) sign if present.
    
75. 
    
76. If the value of the Base parameter is 0, the string determines the base. Thus,
    
77. after an optional leading sign, a leading 0 indicates octal conversion, and a
    
78. leading 0x or 0X indicates hexadecimal conversion. The default is to use decimal
    
79. conversion.
    
80. 
    
81. Parameters
    
82. 
    
83. String Points to the character string to be converted.
    
84. 
    
85. EndPointer Points to a character string that contains the first character not
    
86. converted.
    
87. 
    
88. Base Specifies the base to use for the conversion.
    
89. 
    
90. Return Values
    
91. 
    
92. Upon successful completion, the strtol, strtoul, strtoll, and strtoull
    
93. subroutines return the converted value. If no conversion could be performed, 0
    
94. is returned, and the errno global variable is set to indicate the error. If the
    
95. correct value is outside the range of representable values, the strtol
    
96. subroutine returns a value of LONG_MAX or LONG_MIN according to the sign of the
    
97. value, while the strtoul subroutine returns a value of ULONG_MAX.
    
98. 
    
99. Error Codes
    
100. 
     
101. The strtol and strtoul subroutines return the following error codes:
     
102. 
     
103. ERANGE The correct value of the converted number causes underflow or overflow.
     
104. 
     
105. EINVAL The value of the Base parameter is not valid.
     

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kennhh

苦啊，hp－unix没有strtoll的函数，：（

有没有将16进制直接转换成10进制的double或float型函数？

auser

益出了。
自己编函数来解决。

lenovo

没有。既然溢出了，就想想别的办法吧。

kennhh

：（

谢谢俩位！