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diff --git a/man3/abs.3 b/man3/abs.3 new file mode 100644 index 000000000..4c60f1d38 --- /dev/null +++ b/man3/abs.3 @@ -0,0 +1,80 @@ +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified Mon Mar 29 22:31:13 1993, David Metcalfe +.\" Modified Sun Jun 6 23:27:50 1993, David Metcalfe +.\" Modified Sat Jul 24 21:45:37 1993, Rik Faith (faith@cs.unc.edu) +.\" Modified Sat Dec 16 15:02:59 2000, Joseph S. Myers +.\" +.TH ABS 3 2000-12-17 "GNU" "Linux Programmer's Manual" +.SH NAME +abs, labs, llabs, imaxabs \- compute the absolute value of an integer +.SH SYNOPSIS +.nf +.B #include <stdlib.h> +.sp +.BI "int abs(int " j ); +.br +.BI "long int labs(long int " j ); +.br +.BI "long long int llabs(long long int " j ); +.sp +.B #include <inttypes.h> +.sp +.BI "intmax_t imaxabs(intmax_t " j ); +.fi +.SH DESCRIPTION +The \fBabs()\fP function computes the absolute value of the integer +argument \fIj\fP. The \fBlabs()\fP, \fBllabs()\fP and \fBimaxabs()\fP +functions compute the absolute value of the argument \fIj\fP of the +appropriate integer type for the function. +.SH "RETURN VALUE" +Returns the absolute value of the integer argument, of the appropriate +integer type for the function. +.SH "CONFORMING TO" +SVID 3, POSIX.1, BSD 4.3, ISO/IEC 9899 (C99). POSIX.1 (1996 edition) only +requires the \fBabs()\fP function. ISO/IEC 9899:1990 (C89) only +includes the \fBabs()\fP and \fBlabs()\fP functions; the functions +\fBllabs()\fP and \fBimaxabs()\fP were added in C99. +.SH NOTES +Trying to take the absolute value of the most negative integer +is not defined. +.PP +The \fBllabs()\fP function is included in glibc since version 2.0, but +is not in libc5 or libc4. The \fBimaxabs()\fP function is included in +glibc since version 2.1.1. +.PP +For \fBllabs()\fP to be declared, it may be necessary to define +\fB_ISOC99_SOURCE\fP or \fB_ISOC9X_SOURCE\fP (depending on the +version of glibc) before including any standard headers. +.PP +GCC handles \fBabs()\fP and \fBlabs()\fP as builtin functions. GCC +3.0 also handles \fBllabs()\fP and \fBimaxabs()\fP as builtins. +.SH "SEE ALSO" +.BR ceil (3), +.BR fabs (3), +.BR floor (3), +.BR rint (3) |