1*48349Scael.\" Copyright (c) 1991 The Regents of the University of California. 242104Sbostic.\" All rights reserved. 320290Smckusick.\" 442104Sbostic.\" %sccs.include.redist.man% 542104Sbostic.\" 6*48349Scael.\" @(#)atof.3 6.3 (Berkeley) 04/19/91 742104Sbostic.\" 8*48349Scael.Dd 9*48349Scael.Dt ATOF 3 10*48349Scael.Os 11*48349Scael.Sh NAME 12*48349Scael.Nm atof 13*48349Scael.Nd convert 14*48349Scael.Tn ASCII 15*48349Scaelstring to double 16*48349Scael.Sh SYNOPSIS 17*48349Scael.Fd #include <stdlib.h> 18*48349Scael.Ft double 19*48349Scael.Fn atof "const char *nptr" 20*48349Scael.Sh DESCRIPTION 2142104SbosticThe 22*48349Scael.Fn atof 2342104Sbosticfunction converts the initial portion of the string pointed to by 24*48349Scael.Ar nptr 2542104Sbosticto 26*48349Scael.Ar double 2742104Sbosticrepresentation. 28*48349Scael.Pp 2942104SbosticIt is equivalent to: 30*48349Scael.Bd -literal -offset indent 3142104Sbosticstrtod(nptr, (char **)NULL); 32*48349Scael.Ed 33*48349Scael.Sh SEE ALSO 34*48349Scael.Xr atoi 3 , 35*48349Scael.Xr atol 3 , 36*48349Scael.Xr strtod 3 , 37*48349Scael.Xr strtol 3 , 38*48349Scael.Xr strtoul 3 39*48349Scael.Sh STANDARDS 40*48349ScaelThe 41*48349Scael.Fn atof 42*48349Scaelfunction conforms to 43*48349Scael.St -ansiC . 44*48349Scael.Sh BUGS 4542104SbosticThis manual page represents intent instead of actual practice. 4642104SbosticWhile it is intended that 47*48349Scael.Fn atof 4842104Sbosticbe implemented using 49*48349Scael.Xr strtod 3 , 5042104Sbosticthis has not yet happened. 5142104SbosticIn the current system, 52*48349Scael.Fn atof 53*48349Scaeltranslates a string in the following form to a double: a string of 54*48349Scaelleading white space, possibly followed by a sign (``+'' or ``-''), 55*48349Scaelfollowed by a digit string which may contain one decimal point (``.''), 56*48349Scaelwhich may be followed by either of the exponent flags (``E'' or ``e''), 57*48349Scaeland lastly, followed by a signed or unsigned integer. 58