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atof(3) — Linux manual page

atof(3)                  Library Functions Manualatof(3)

NAME        top

       atof - convert a string to a double

LIBRARY        top

       Standard C library (libc,-lc)

SYNOPSIS        top

#include <stdlib.h>double atof(const char *nptr);

DESCRIPTION        top

       Theatof() function converts the initial portion of the string       pointed to bynptr todouble.  The behavior is the same as           strtod(nptr, NULL);       except thatatof() does not detect errors.

RETURN VALUE        top

       The converted value.

ATTRIBUTES        top

       For an explanation of the terms used in this section, seeattributes(7).       ┌───────────────────────────────┬───────────────┬────────────────┐       │Interface│Attribute│Value│       ├───────────────────────────────┼───────────────┼────────────────┤       │atof()                        │ Thread safety │ MT-Safe locale │       └───────────────────────────────┴───────────────┴────────────────┘

STANDARDS        top

       C11, POSIX.1-2008.

HISTORY        top

       POSIX.1-2001, C89, C99, SVr4, 4.3BSD.

SEE ALSO        top

atoi(3),atol(3),strfromd(3),strtod(3),strtol(3),strtoul(3)

COLOPHON        top

       This page is part of theman-pages (Linux kernel and C library       user-space interface documentation) project.  Information about       the project can be found at        ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report       for this manual page, see       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.       This page was obtained from the tarball man-pages-6.15.tar.gz       fetched from       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on       2025-08-11.  If you discover any rendering problems in this HTML       version of the page, or you believe there is a better or more up-       to-date source for the page, or you have corrections or       improvements to the information in this COLOPHON (which isnot       part of the original manual page), send a mail to       man-pages@man7.orgLinux man-pages 6.15            2025-05-17atof(3)

Pages that refer to this page:atoi(3), strfromd(3), strtod(3), strtol(3), strtoul(3)

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