NetBSD/lib/libutil/strpct.3

.\" $NetBSD: strpct.3,v 1.4 2012/01/07 18:40:55 christos Exp $
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.\" This file was contributed to The NetBSD Foundation by Christos Zoulas.
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.Dd January 7, 2012
.Dt STRPCT 3
.Os
.Sh NAME
.Nm strpct ,
.Nm strspct
.Nd decimal percent formatters
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.In util.h
.Ft char *
.Fn strpct "char *buf" "size_t bufsiz" "uintmax_t numerator" "uintmax_t denominator" "size_t precision"
.Ft char *
.Fn strspct "char *buf" "size_t bufsiz" "intmax_t numerator" "intmax_t denominator" "size_t precision"
.Sh DESCRIPTION
The
.Fn strpct
function formats the fraction represented by
.Fa numerator
and
.Fa denominator
into a percentage representation with given number of digits of
.Fa precision
without using floating point arithmetic.
.Sh RETURN VALUES
.Fn strpct
and
.Fn strspct
always return a pointer to a NUL-terminated (unless
.Fa buflen
is
.Dv 0 )
formatted string which
is placed in
.Fa buf
and is up to
.Fa buflen
characters.
If there was an overflow, the formatted string will reflect that precision
loss.
.Sh EXAMPLES
.Bd -literal -offset indent
strpct(buf, buflen, 1, 16, 3);
\(rA "6.250"
strpct(buf, buflen, 1, 2, 0);
\(rA "50"
.Ed
.Sh HISTORY
.Fn strpct
was originally implemented in
.Xr csh 1
for
.Nx 1.3 .
It printed into a static buffer, was not locale aware, handled
.Ft unsigned long
numbers, and printed a
.Dq %
at the end of the number.
Other programs such as
.Xr df 1
and
.Xr time 1
started using it.
.Fn strpct
and
.Fn strspct
appeared separately in libutil for
.Nx 6.0 .
.Sh AUTHORS
.An Erik E. Fair Aq fair@netbsd.org