1 /* $NetBSD: mstolfp.c,v 1.7 2016/01/08 21:35:38 christos Exp $ */ 2 3 /* 4 * mstolfp - convert an ascii string in milliseconds to an l_fp number 5 */ 6 #include <config.h> 7 #include <stdio.h> 8 #include <ctype.h> 9 10 #include "ntp_fp.h" 11 #include "ntp_stdlib.h" 12 13 int 14 mstolfp( 15 const char *str, 16 l_fp *lfp 17 ) 18 { 19 register const char *cp; 20 register char *bp; 21 register const char *cpdec; 22 char buf[100]; 23 24 /* 25 * We understand numbers of the form: 26 * 27 * [spaces][-][digits][.][digits][spaces|\n|\0] 28 * 29 * This is one enormous hack. Since I didn't feel like 30 * rewriting the decoding routine for milliseconds, what 31 * is essentially done here is to make a copy of the string 32 * with the decimal moved over three places so the seconds 33 * decoding routine can be used. 34 */ 35 bp = buf; 36 cp = str; 37 while (isspace((unsigned char)*cp)) 38 cp++; 39 40 if (*cp == '-') { 41 *bp++ = '-'; 42 cp++; 43 } 44 45 if (*cp != '.' && !isdigit((unsigned char)*cp)) 46 return 0; 47 48 49 /* 50 * Search forward for the decimal point or the end of the string. 51 */ 52 cpdec = cp; 53 while (isdigit((unsigned char)*cpdec)) 54 cpdec++; 55 56 /* 57 * Found something. If we have more than three digits copy the 58 * excess over, else insert a leading 0. 59 */ 60 if ((cpdec - cp) > 3) { 61 do { 62 *bp++ = (char)*cp++; 63 } while ((cpdec - cp) > 3); 64 } else { 65 *bp++ = '0'; 66 } 67 68 /* 69 * Stick the decimal in. If we've got less than three digits in 70 * front of the millisecond decimal we insert the appropriate number 71 * of zeros. 72 */ 73 *bp++ = '.'; 74 if ((cpdec - cp) < 3) { 75 size_t i = 3 - (cpdec - cp); 76 do { 77 *bp++ = '0'; 78 } while (--i > 0); 79 } 80 81 /* 82 * Copy the remainder up to the millisecond decimal. If cpdec 83 * is pointing at a decimal point, copy in the trailing number too. 84 */ 85 while (cp < cpdec) 86 *bp++ = (char)*cp++; 87 88 if (*cp == '.') { 89 cp++; 90 while (isdigit((unsigned char)*cp)) 91 *bp++ = (char)*cp++; 92 } 93 *bp = '\0'; 94 95 /* 96 * Check to make sure the string is properly terminated. If 97 * so, give the buffer to the decoding routine. 98 */ 99 if (*cp != '\0' && !isspace((unsigned char)*cp)) 100 return 0; 101 return atolfp(buf, lfp); 102 } 103