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.TH ARES_LIBRARY_INIT 3 "19 May 2009"
.SH NAME
ares_library_init \- c-ares library initialization
.SH SYNOPSIS
.nf
.B #include <ares.h>
.PP
.B int ares_library_init(int \fIflags\fP)
.fi
.SH DESCRIPTION
.PP
The
.B ares_library_init
function performs initializations internally required by the c-ares
library that must take place before any other c-ares function can be
used.
.PP
This function must be called one time within the life of a program
before the program actually executes any other c-ares library function
call. Initializations done by this function remain effective until a
call to \fIares_library_cleanup(3)\fP is performed.
.PP
Successive calls to this function are ignored, only the first one with
c-ares in an uninitialized state is effective.
.PP
The
.I flags
parameter is a bit pattern that tells c-ares exactly which features
should be initialized, as described below. Set the desired bits by
ORing the values together. In normal operation, you must specify
.I ARES_LIB_INIT_ALL.
Don't use any other value unless you are familiar with it and trying
to control some internal c-ares features.
.PP
.B This function is not thread safe.
You have to call it once the program
has started but must be called before the program starts any other thread.
Due to the fact that ares_library_init() might call functions from other
libraries that are thread unsafe, it could conflict with any other thread
that uses these other libraries.
.SH FLAGS
.TP 5
.B ARES_LIB_INIT_ALL
Initialize everything possible. This sets all known bits.
.TP
.B ARES_LIB_INIT_WIN32
Initialize Win32 specific libraries.
.TP
.B ARES_LIB_INIT_NONE
Initialize nothing extra. This sets no bit.
.SH RETURN VALUE
If this function returns non-zero, something went wrong and you cannot
use the other c-ares functions.
.SH NOTES
This function was first introduced in c-ares version 1.6.1 along with
the definition of preprocessor symbol CARES_HAVE_ARES_LIBRARY_INIT
as an indication of the availability of this function.
.SH SEE ALSO
.BR ares_library_cleanup (3)
.SH AUTHOR
Yang Tse