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atof(2) [plan9 man page]

ATOF(2) 							System Calls Manual							   ATOF(2)

atof, atoi, atol, charstod, strtod, strtol, strtoul - convert text to numbers SYNOPSIS
#include <u.h> #include <libc.h> double atof(char *nptr) int atoi(char *nptr) long atol(char *nptr) double charstod(int (*f)(void *), void *a) double strtod(char *nptr, char **rptr) long strtol(char *nptr, char **rptr, int base) ulong strtoul(char *nptr, char **rptr, int base) /* Alef only */ int strtoi(byte *nptr, byte **rptr, int base) uint strtoui(byte *nptr, byte **rptr, int base) float strtof(byte *nptr, byte **rptr); DESCRIPTION
Atof, atoi, and atol convert a string pointed to by nptr to floating, integer, and long integer representation respectively. The first unrecognized character ends the string. Leading C escapes are understood, as in strtol with base zero. Atof recognizes an optional string of tabs and spaces, then an optional sign, then a string of digits optionally containing a decimal point, then an optional or followed by an optionally signed integer. Atoi and atol recognize an optional string of tabs and spaces, then an optional sign, then a string of decimal digits. Strtod, strtol, and strtoul behave similarly to atof and atol and, if rptr is not zero, set *rptr to point to the input character immedi- ately after the string converted. Strtol and strtoul interpret the digit string in the specified base, from 2 to 36, each digit being less than the base. Digits with value over 9 are represented by letters, a-z or A-Z. If base is 0, the input is interpreted as an integral constant in the style of C (with no suffixed type indicators): numbers are octal if they begin with hexadecimal if they begin with or otherwise decimal. Strtoul does not rec- ognize signs. Charstod interprets floating point numbers like atof, but it gets successive characters by calling (*f)(a). The last call to f terminates the scan, so it must have returned a character that is not a legal continuation of a number. Therefore, it may be necessary to back up the input stream one character after calling charstod. Alef The routines strtol and strtoul are renamed strtoi and strtoui and return type int and uint. There is no charstod or atof. Instead, strtof is like a floating-point base 10 strtoi. SOURCE
/sys/src/libc/port SEE ALSO
Zero is returned if the beginning of the input string is not interpretable as a number; even in this case, rptr will be updated. These routines set errstr. BUGS
Atoi and atol accept octal and hexadecimal numbers in the style of C, contrary to the ANSI specification. ATOF(2)

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ATOI(3)                                                      Linux Programmer's Manual                                                     ATOI(3)

atoi, atol, atoll - convert a string to an integer SYNOPSIS
#include <stdlib.h> int atoi(const char *nptr); long atol(const char *nptr); long long atoll(const char *nptr); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): atoll(): __ISOC99_SOURCE || || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE DESCRIPTION
The atoi() function converts the initial portion of the string pointed to by nptr to int. The behavior is the same as strtol(nptr, NULL, 10); except that atoi() does not detect errors. The atol() and atoll() functions behave the same as atoi(), except that they convert the initial portion of the string to their return type of long or long long. RETURN VALUE
The converted value. ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +------------------------+---------------+----------------+ |Interface | Attribute | Value | +------------------------+---------------+----------------+ |atoi(), atol(), atoll() | Thread safety | MT-Safe locale | +------------------------+---------------+----------------+ CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99, SVr4, 4.3BSD. C89 and POSIX.1-1996 include the functions atoi() and atol() only. NOTES
Linux libc provided atoq() as an obsolete name for atoll(); atoq() is not provided by glibc. SEE ALSO
atof(3), strtod(3), strtol(3), strtoul(3) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at GNU 2016-03-15 ATOI(3)
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