csu3_am335x/EVSE/GPL/plc-utils.LNX.2.1.20/source/tools/strfbits.c

/*====================================================================*
 *
 *   size_t strfbits (char  buffer [], size_t length, char const * operands [], char const * operator, unsigned flagword);
 *
 *   format.h
 *
 *   format buffer with an enumerated list of the bits in a flagword; 
 *   each flagword bit position corresponds to a string in operands[]
 *   and operator is the string separating formatted operands;
 *
 *   enumeration continues until all bits are enumerated or operands
 *   are exhausted or the buffer fills;
 *
 *   for example, the following formats buffer with the literal string
 *   "one, three, five, six" since those bits are set;
 *
 *   char buffer[100];
 *   char const operator = ", ";
 *   char const *operands[] = 
 *   { 
 *      "zero", 
 *      "one", 
 *      "two", 
 *      "three", 
 *      "four", 
 *      "five", 
 *      "six", 
 *      "seven", 
 *      "eight",
 *      "nine",
 *      "ten",
 *      (char *)(0) 
 *   };
 *   flag_t flags = 0x006C;
 *
 *   strfbits (buffer, sizeof(buffer), operands, operator, flags);
 *
 *   we decrement length before starting to reserve room for the NUL
 *   terminator; not room ... no write; we then add length to buffer
 *   before to compute the terminator address then subtract it after
 *   to compute the buffer start; this minimizes indexing and offset 
 *   calculations within the loop; 
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

#ifndef STRFBITS_SOURCE
#define STRFBITS_SOURCE

#include <unistd.h>

#include "../tools/memory.h"
#include "../tools/flags.h"

size_t strfbits (char buffer [], size_t length, char const * operands [], char const * operator, unsigned flagword) 

{ 
	char * string = (char *) (buffer); 
	char const * separator = ""; 
	if (length--) 
	{ 
		buffer += length; 
		while ((* operands) && (flagword)) 
		{ 
			if (flagword & 1) 
			{ 
				char const * symbol; 
				for (symbol = separator; (* symbol) && (string < buffer); symbol++) 
				{ 
					* string++ = * symbol; 
				} 
				for (symbol = * operands; (* symbol) && (string < buffer); symbol++) 
				{ 
					* string++ = * symbol; 
				} 
				separator = operator; 
			} 
			flagword >>= 1; 
			operands++; 
		} 
		* string = (char) (0); 
		buffer -= length; 
	} 
	return (string - (char *) (buffer)); 
} 

#endif