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by shigemk2

当面は技術的なことしか書かない

maptabとpartab

Unix

maptab[]

端末は文字セットにASCIIコードを用いる

純粋な文字として扱うためには\のあとに入力しないといけない文字をmaptabで管理している

dmr/tty.c

/*
 * Input mapping table-- if an entry is non-zero, when the
 * corresponding character is typed preceded by "\" the escape
 * sequence is replaced by the table value.  Mostly used for
 * upper-case only terminals.
 */
char   maptab[]
{
    000,000,000,000,004,000,000,000,
    000,000,000,000,000,000,000,000,
    000,000,000,000,000,000,000,000,
    000,000,000,000,000,000,000,000,
    000,'|',000,'#',000,000,000,'`',
    '{','}',000,000,000,000,000,000,
    000,000,000,000,000,000,000,000,
    000,000,000,000,000,000,000,000,
    '@',000,000,000,000,000,000,000,
    000,000,000,000,000,000,000,000,
    000,000,000,000,000,000,000,000,
    000,000,000,000,000,000,'~',000,
    000,'A','B','C','D','E','F','G',
    'H','I','J','K','L','M','N','O',
    'P','Q','R','S','T','U','V','W',
    'X','Y','Z',000,000,000,000,000,
};

partab[]

パリティビット - Wikipedia

文字列の出力処理に使われる

/*
 */

char partab[] {
    0001,0201,0201,0001,0201,0001,0001,0201,
    0202,0004,0003,0205,0005,0206,0201,0001,
    0201,0001,0001,0201,0001,0201,0201,0001,
    0001,0201,0201,0001,0201,0001,0001,0201,
    0200,0000,0000,0200,0000,0200,0200,0000,
    0000,0200,0200,0000,0200,0000,0000,0200,
    0000,0200,0200,0000,0200,0000,0000,0200,
    0200,0000,0000,0200,0000,0200,0200,0000,
    0200,0000,0000,0200,0000,0200,0200,0000,
    0000,0200,0200,0000,0200,0000,0000,0200,
    0000,0200,0200,0000,0200,0000,0000,0200,
    0200,0000,0000,0200,0000,0200,0200,0000,
    0000,0200,0200,0000,0200,0000,0000,0200,
    0200,0000,0000,0200,0000,0200,0200,0000,
    0200,0000,0000,0200,0000,0200,0200,0000,
    0000,0200,0200,0000,0200,0000,0000,0201
};