xo_emit_err - Man Page

Text, XML, JSON, and HTML Output Emission Library (libxo, -lxo)

#include <libxo/xo.h>

void
xo_emit_warn(const char *fmt, ...);

void
xo_emit_warnx(const char *fmt, ...);

void
xo_emit_warn_c(int code, const char *fmt, ...);

void
xo_emit_warn_hc(xo_handle_t *xop, int code, const char *fmt, ...);

void
xo_emit_err(int eval, const char *fmt, ...);

void
xo_emit_errc(int eval, int code, const char *fmt, ...);

void
xo_emit_errx(int eval, const char *fmt, ...);

Many programs make use of the standard library functions err(3) and warn(3) to generate errors and warnings for the user. libxo wants to pass that information via the current output style, and provides compatible functions to allow this.

The fmt argument is one compatible with xo_emit(3) which allows these functions make structured data. To generate unstructured data, use the xo_err(3) functions.

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.

    EXAMPLE:
        if (open(filename, O_RDONLY) < 0)
            xo_err(1, "cannot open file '%s'", filename);

xo_emit(3), xo_format(5), xo_err(3), libxo(3)

The libxo library first appeared in FreeBSD 11.0.

libxo was written by Phil Shafer <phil@freebsd.org>.

FreeBSD uses libxo version 1.6.0. Complete documentation can be found on github:

https://juniper.github.io/libxo/1.6.0/html/index.html

libxo lives on github as:

https://github.com/Juniper/libxo

The latest release of libxo is available at:

https://github.com/Juniper/libxo/releases

The libxo library was added in FreeBSD 11.0.

Phil Shafer

libxo(3), xo_err(3).