bintoasc.c

一个c语言写做的编译器的源码

/*@A (C) 1992 Allen I. Holub                                                */
#include <stdio.h>
#include <tools/debug.h>
#include <tools/compiler.h>	/* for prototypes only */

char	*bin_to_ascii( c, use_hex )
int c;
int use_hex;
{
    /* Return a pointer to a string that represents c. This will be the
     * character itself for normal characters and an escape sequence (\n, \t,
     * \x00, etc., for most others). A ' is represented as \'. The string will
     * be destroyed the next time bin_to_ascii() is called. If "use_hex" is true
     * then \xDD escape sequences are used. Otherwise, octal sequences (\DDD)
     * are used. (see also: pchar.c)
     */

    static char buf[8];

    c &= 0xff ;
    if( ' ' <= c  &&  c < 0x7f  &&  c != '\'' && c != '\\')
    {
	buf[0] = c;
	buf[1] = '\0';
    }
    else
    {
	buf[0] = '\\' ;
	buf[2] = '\0' ;

	switch(c)
	{
	case '\\': buf[1] = '\\'; break;
	case '\'': buf[1] = '\''; break;
	case '\b': buf[1] = 'b' ; break;
	case '\f': buf[1] = 'f' ; break;
	case '\t': buf[1] = 't' ; break;
	case '\r': buf[1] = 'r' ; break;
	case '\n': buf[1] = 'n' ; break;
	default  : sprintf( &buf[1], use_hex ? "x%03x" : "%03o", c );
		   break;
	}
    }
    return buf;
}