/* Copyright 1982 Alcyon Corporation 8716 Production Ave. San Diego, Ca. 92121 */ /*char *version "@(#) ftoa - jan 24, 1982"; */ /* * IEEE Floating Point to Ascii String Conversion Routine : * IEEE Standard Single Precision Representation Floating Point * * char * * ftoa(f,buf,prec) * float f; * char *buf; * int prec; * * No more than 9 decimal digits are allowed in single precision. * Largest positive number is 3.4 * 10^33 and the smallest positive * number is 1.2 * 10^-38. * Rely's on the fact that a long and a float are both 32 bits. */ #define BIAS 127L float _ieeetof(); char * ftoa(fl,buf,prec) long fl; /* ieee formatted float */ char *buf; int prec; { register char *bp; register int exp, digit; float f; prec = (prec <= 0) ? 1 : (prec <= 9) ? prec : 9; bp = buf; f = _ieeetof(fl); /* get floating point value */ if (f < 0.0) { /* negative float */ *bp++ = '-'; f = -f; /* make it positive */ } if (f == 0.0) { *bp++ = '0'; *bp++ = '.'; while (prec--) *bp++ = '0'; *bp = 0; return(buf); } for (exp=0; f < 1.0; f = f * 10.0) /* get negative exp */ exp--; for ( ; f >= 1.0; f = f / 10.0) /* 0.XXXXXXE00 * 10^exp */ exp++; if (exp<=0) /* one significant digit */ *bp++ = '0'; for ( ; exp>0; exp--) { /* get significant digits */ f = f * 10.0; digit = f; /* get one digit */ f = f - digit; *bp++ = digit + '0'; } *bp++ = '.'; for( ; exp<0 && prec; prec--, exp++) /* exp < 0 ? */ *bp++ = '0'; while(prec-- > 0) { f = f * 10.0; digit = f; /* get one digit */ f = f - digit; *bp++ = digit + '0'; } *bp = 0; return(buf); }