.\" #
.\" # Copyright (c) 2014, Juniper Networks, Inc.
.\" # All rights reserved.
.\" # This SOFTWARE is licensed under the LICENSE provided in the
.\" # ../Copyright file. By downloading, installing, copying, or 
.\" # using the SOFTWARE, you agree to be bound by the terms of that
.\" # LICENSE.
.\" # Phil Shafer, July 2014
.\" 
.Dd July, 2014
.Dt LIBXO 3
.Os
.Sh NAME
.Nm xo_err
.Nd emit errors and warnings in multiple formats
.Sh LIBRARY
.Lb libxo
.Sh SYNOPSIS
.In libxo/xo.h
.Ft void
.Fn xo_warn "const char *fmt"  "..."
.Ft void
.Fn xo_warnx "const char *fmt" "..."
.Ft void
.Fn xo_warn_c "int code" "const char *fmt" "..."
.Ft void
.Fn xo_warn_hc "xo_handle_t *xop" "int code, const char *fmt" "..."
.Ft void
.Fn xo_err "int eval" "const char *fmt" "..."
.Ft void
.Fn xo_errc "int eval" "int code" "const char *fmt" "..."
.Ft void
.Fn xo_errx "int eval" "const char *fmt" "..."
.Ft void
.Fn xo_message "const char *fmt" "..."
.Ft void
.Fn xo_message_c "int code" "const char *fmt" "..."
.Ft void
.Fn xo_message_hc "xo_handle_t *xop" "int code, const char *fmt" "..."
.Ft void
.Fn xo_message_hcv "xo_handle_t *xop" "int code" "const char *fmt" "va_list vap"
.Sh DESCRIPTION
Many programs make use of the standard library functions
.Xr err 3
and
.Xr warn 3
to generate errors and warnings for the user.
.Em libxo
wants to
pass that information via the current output style, and provides
compatible functions to allow this.
.Pp
These functions display the program name, a colon, a formatted message
based on the arguments, and then optionally a colon and an error
message associated with either "errno" or the "code" parameter.
.Bd -literal -offset indent
    EXAMPLE:
        if (open(filename, O_RDONLY) < 0)
            xo_err(1, "cannot open file '%s'", filename);
.Ed
.Sh ADDITIONAL DOCUMENTATION
.Pp
Complete documentation can be found on github:
.Bd -literal -offset indent
http://juniper.github.io/libxo/libxo-manual.html
.Ed
.Pp
libxo lives on github as:
.Bd -literal -offset indent
https://github.com/Juniper/libxo
.Ed
.Pp
The latest release of libxo is available at:
.Bd -literal -offset indent
https://github.com/Juniper/libxo/releases
.Ed
.Sh SEE ALSO
.Xr xo_emit 3
.Sh HISTORY
The
.Fa libxo
library was added in FreeBSD 11.0.
.Sh AUTHOR
Phil Shafer