C/C++下ASCII与EBCDIC码之间的轻松转换

EBCDIC (Extended Binary Coded Decimal Interchange Code) 扩增二进式十进交换码，为IBM于1963年－1964年间推出的字符编码表，根据早期打孔机式的二进化十进数(BCD, Bindary Coded Decimal)排列而成。是IBM迷尔级以上电脑的标准码。
ASCII（American Standard Code for Information Interchange，美国信息互换标准代码）是基于拉丁字母的一套电脑编码系统。它主要用于显示现代英语，而其扩展版本EASCII则可以勉强显示其他西欧语言。它是现今最通用的单字节编码系统（但是有被UniCode追上的迹象），并等同于国际标准ISO/IEC 646。
现在尽管ASCII码非常流行，但不少专业格式的数据文件中，仍然在用老式的EBCDIC码存储字符信息。如地震信号记录文件SEG-Y(SEGY)格式等等。只有进行转换只有才能正常显示。其关键也就是建立一个相对应的码表，然后买个字符进行相应的转换即可。
以下是C格式的代码：
/*
** ASCII <=> EBCDIC conversion functions
*/
static unsigned char a2e[256] = {
0, 1, 2, 3, 55, 45, 46, 47, 22, 5, 37, 11, 12, 13, 14, 15,
16, 17, 18, 19, 60, 61, 50, 38, 24, 25, 63, 39, 28, 29, 30, 31,
64, 79,127,123, 91,108, 80,125, 77, 93, 92, 78,107, 96, 75, 97,
240,241,242,243,244,245,246,247,248,249,122, 94, 76,126,110,111,
124,193,194,195,196,197,198,199,200,201,209,210,211,212,213,214,
215,216,217,226,227,228,229,230,231,232,233, 74,224, 90, 95,109,
121,129,130,131,132,133,134,135,136,137,145,146,147,148,149,150,
151,152,153,162,163,164,165,166,167,168,169,192,106,208,161, 7,
32, 33, 34, 35, 36, 21, 6, 23, 40, 41, 42, 43, 44, 9, 10, 27,
48, 49, 26, 51, 52, 53, 54, 8, 56, 57, 58, 59, 4, 20, 62,225,
65, 66, 67, 68, 69, 70, 71, 72, 73, 81, 82, 83, 84, 85, 86, 87,
88, 89, 98, 99,100,101,102,103,104,105,112,113,114,115,116,117,
118,119,120,128,138,139,140,141,142,143,144,154,155,156,157,158,
159,160,170,171,172,173,174,175,176,177,178,179,180,181,182,183,
184,185,186,187,188,189,190,191,202,203,204,205,206,207,218,219,
220,221,222,223,234,235,236,237,238,239,250,251,