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1 | .\" Copyright (c) 1990 The Regents of the University of California. |
| 2 | .\" All rights reserved. | |
| 3 | .\" | |
| 4 | .\" %sccs.include.redist.man% | |
| 5 | .\" | |
| 6 | .\" @(#)strtod.3 5.1 (Berkeley) %G% | |
| 7 | .\" | |
| 8 | .TH STRTOD 3 "" | |
| 9 | .UC 7 | |
| 10 | .SH NAME | |
| 11 | strtod \- convert ASCII string to double | |
| 12 | .SH SYNOPSIS | |
| 13 | .nf | |
| 14 | .ft B | |
| 15 | #include <stdlib.h> | |
| 16 | ||
| 17 | double | |
| 18 | strtod(const char *nptr, char **endptr); | |
| 19 | .ft R | |
| 20 | .fi | |
| 21 | .SH DESCRIPTION | |
| 22 | The | |
| 23 | .I strtod | |
| 24 | function converts the initial portion of the string | |
| 25 | pointed to by | |
| 26 | .I nptr | |
| 27 | to | |
| 28 | .I double | |
| 29 | representation. | |
| 30 | .PP | |
| 31 | The expected form of the string is an optional plus (``+'') or minus | |
| 32 | sign (``-''), followed by a sequence of digits optionally containing | |
| 33 | a decimal-point character, optionally followed by an exponent. | |
| 34 | An exponent consists of an ``E'' or ``e'', followed by an optional plus | |
| 35 | or minus sign, followed by a sequence of digits. | |
| 36 | .PP | |
| 37 | Leading white-space characters in the string (as defined by the | |
| 38 | .IR isspace (3) | |
| 39 | function) are skipped. | |
| 40 | .PP | |
| 41 | The | |
| 42 | .I strtod | |
| 43 | function returns the converted value, if any. | |
| 44 | .PP | |
| 45 | If | |
| 46 | .I endptr | |
| 47 | is not NULL, a pointer to the character after the last character used | |
| 48 | in the conversion is stored in the location referenced by | |
| 49 | .IR endptr . | |
| 50 | .PP | |
| 51 | If no conversion is performed, zero is returned and the value of | |
| 52 | .I nptr | |
| 53 | is stored in the location referenced by | |
| 54 | .IR endptr . | |
| 55 | .PP | |
| 56 | If the correct value would cause overflow, plus or minus | |
| 57 | .I HUGE_VAL | |
| 58 | is returned (according to the sign of the value), and | |
| 59 | .I ERANGE | |
| 60 | is stored in | |
| 61 | .IR errno . | |
| 62 | If the correct value would cause underflow, zero is | |
| 63 | returned and | |
| 64 | .I ERANGE | |
| 65 | is stored in | |
| 66 | .IR errno . | |
| 67 | .SH ERRORS | |
| 68 | .TP | |
| 69 | [ERANGE] | |
| 70 | Overflow or underflow occurred. | |
| 71 | .SH "SEE ALSO" | |
| 72 | atof(3), atoi(3), atol(3), strtol(3), strtoul(3) | |
| 73 | .SH STANDARDS | |
| 74 | .B Strtod | |
| 75 | conforms to ANSI X3.159-1989 (``ANSI C''). | |
| 76 | .SH BUGS | |
| 77 | This manual page represents intent instead of actual practice. | |
| 78 | The | |
| 79 | .IR strtod (3) | |
| 80 | function is not currently available. |