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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
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| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
| commit | 399644e47874bff147afb19c89228901ac39340e (patch) | |
| tree | 1c4c0b733f4c16b5783b41bebb19194a9ef62ad1 /man3/ffs.3 | |
| parent | Initial commit. (diff) | |
| download | manpages-upstream/6.05.01.tar.xz manpages-upstream/6.05.01.zip | |
Adding upstream version 6.05.01.upstream/6.05.01
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man3/ffs.3')
| -rw-r--r-- | man3/ffs.3 | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/man3/ffs.3 b/man3/ffs.3 new file mode 100644 index 0000000..b092438 --- /dev/null +++ b/man3/ffs.3 @@ -0,0 +1,104 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified Sat Jul 24 19:39:35 1993 by Rik Faith (faith@cs.unc.edu) +.\" +.\" Modified 2003 Walter Harms (walter.harms@informatik.uni-oldenburg.de) +.\" +.TH ffs 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +ffs, ffsl, ffsll \- find first bit set in a word +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <strings.h> +.PP +.BI "int ffs(int " i ); +.PP +.B #include <string.h> +.PP +.BI "int ffsl(long " i ); +.BI "int ffsll(long long " i ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR ffs (): +.nf + Since glibc 2.12: + _XOPEN_SOURCE >= 700 + || ! (_POSIX_C_SOURCE >= 200809L) + || /* glibc >= 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE + Before glibc 2.12: + none +.fi +.PP +.BR ffsl (), +.BR ffsll (): +.nf + Since glibc 2.27: +.\" glibc commit 68fe16dd327c895c08b9ee443b234c49c13b36e9 + _DEFAULT_SOURCE + Before glibc 2.27: + _GNU_SOURCE +.fi +.SH DESCRIPTION +The +.BR ffs () +function returns the position of the first +(least significant) bit set in the word \fIi\fP. +The least significant bit is position 1 and the +most significant position is, for example, 32 or 64. +The functions +.BR ffsll () +and +.BR ffsl () +do the same but take +arguments of possibly different size. +.SH RETURN VALUE +These functions return the position of the first bit set, +or 0 if no bits are set in +.IR i . +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR ffs (), +.BR ffsl (), +.BR ffsll () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH VERSIONS +BSD systems have a prototype in +.IR <string.h> . +.SH STANDARDS +.TP +.BR ffs () +POSIX.1-2001, POSIX.1-2008, 4.3BSD. +.TP +.BR ffsl () +.TQ +.BR ffsll () +GNU. +.SH SEE ALSO +.BR memchr (3) |