fmtstrtod.3 (1285B)
1 .TH FMTSTRTOD 3 2 .SH NAME 3 fmtstrtod, fmtcharstod \ - convert text to numbers 4 .SH SYNOPSIS 5 .B #include <utf.h> 6 .br 7 .B #include <fmt.h> 8 .PP 9 .PP 10 .B 11 double fmtstrtod(char *nptr, char **rptr) 12 .PP 13 .B 14 double fmtcharstod(int (*f)(void *), void *a) 15 .SH DESCRIPTION 16 .I Fmtstrtod 17 converts a string pointed to by 18 .I nptr 19 to floating point representation and, if 20 .I rptr 21 is not zero, sets 22 .I *rptr 23 to point to the input character immediately after the string converted. 24 .I Fmtstrtod 25 recognizes an optional string of tabs and spaces, 26 then an optional sign, then a string of digits optionally 27 containing a decimal point, then an optional 28 .L e 29 or 30 .L E 31 followed by an optionally signed integer. 32 .PP 33 .PP 34 .I Fmtcharstod 35 interprets floating point numbers in the manner of 36 .IR atof , 37 but gets successive characters by calling 38 .BR (*\fIf\fP)(a) . 39 The last call to 40 .I f 41 terminates the scan, so it must have returned a character that 42 is not a legal continuation of a number. 43 Therefore, it may be necessary to back up the input stream one character 44 after calling 45 .IR fmtcharstod . 46 .SH SOURCE 47 .B https://9fans.github.io/plan9port/unix 48 .SH SEE ALSO 49 .IR fscanf (3) 50 .SH DIAGNOSTICS 51 Zero is returned if the beginning of the input string is not interpretable 52 as a number; even in this case, 53 .I rptr 54 will be updated.