1*61180Sbostic.\" Copyright (c) 1991, 1993 2*61180Sbostic.\" The Regents of the University of California. All rights reserved. 320290Smckusick.\" 450283Sbostic.\" This code is derived from software contributed to Berkeley by 550283Sbostic.\" the American National Standards Committee X3, on Information 650283Sbostic.\" Processing Systems. 750283Sbostic.\" 842104Sbostic.\" %sccs.include.redist.man% 942104Sbostic.\" 10*61180Sbostic.\" @(#)atof.3 8.1 (Berkeley) 06/04/93 1142104Sbostic.\" 1248349Scael.Dd 1348349Scael.Dt ATOF 3 1448349Scael.Os 1548349Scael.Sh NAME 1648349Scael.Nm atof 1748349Scael.Nd convert 1848349Scael.Tn ASCII 1948349Scaelstring to double 2048349Scael.Sh SYNOPSIS 2148349Scael.Fd #include <stdlib.h> 2248349Scael.Ft double 2348349Scael.Fn atof "const char *nptr" 2448349Scael.Sh DESCRIPTION 2542104SbosticThe 2648349Scael.Fn atof 2742104Sbosticfunction converts the initial portion of the string pointed to by 2848349Scael.Ar nptr 2942104Sbosticto 3048349Scael.Ar double 3142104Sbosticrepresentation. 3248349Scael.Pp 3342104SbosticIt is equivalent to: 3448349Scael.Bd -literal -offset indent 3542104Sbosticstrtod(nptr, (char **)NULL); 3648349Scael.Ed 3748349Scael.Sh SEE ALSO 3848349Scael.Xr atoi 3 , 3948349Scael.Xr atol 3 , 4048349Scael.Xr strtod 3 , 4148349Scael.Xr strtol 3 , 4248349Scael.Xr strtoul 3 4348349Scael.Sh STANDARDS 4448349ScaelThe 4548349Scael.Fn atof 4648349Scaelfunction conforms to 4748349Scael.St -ansiC . 4848349Scael.Sh BUGS 4942104SbosticThis manual page represents intent instead of actual practice. 5042104SbosticWhile it is intended that 5148349Scael.Fn atof 5242104Sbosticbe implemented using 5348349Scael.Xr strtod 3 , 5442104Sbosticthis has not yet happened. 5542104SbosticIn the current system, 5648349Scael.Fn atof 5748349Scaeltranslates a string in the following form to a double: a string of 5848349Scaelleading white space, possibly followed by a sign (``+'' or ``-''), 5948349Scaelfollowed by a digit string which may contain one decimal point (``.''), 6048349Scaelwhich may be followed by either of the exponent flags (``E'' or ``e''), 6148349Scaeland lastly, followed by a signed or unsigned integer. 62