xo_set_program, libxo, xo_parse_args(3)	detect, parse, and remove arguments for libxo
xo_parse_args, libxo, xo_set_program(3)	detect, parse, and remove arguments for libxo

NAME

xo_parse_args, xo_set_program — detect, parse, and remove arguments for libxo

LIBRARY

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

SYNOPSIS

#include <libxo/xo.h>

int
xo_parse_args(int argc, char **argv);

int
xo_set_program(const char *name);

DESCRIPTION

The xo_parse_args() function is used to process command-line arguments. libxo specific options are processed and removed from the argument list so the calling application does not need to process them. If successful, a new value for argc is returned. On failure, a message it emitted and -1 is returned.

    argc = xo_parse_args(argc, argv);
    if (argc < 0)
        exit(EXIT_FAILURE);

Following the call to xo_parse_args(), the application can process the remaining arguments in a normal manner.

libxo uses command line options to trigger rendering behavior. The following options are recognised:

: --libxo <options>
: --libxo=<options>
: --libxo:<brief-options>

Options is a comma-separated list of tokens that correspond to output styles, flags, or features:

Token Action
dtrt: Enable "Do The Right Thing" mode
html: Emit HTML output
indent=xx: Set the indentation level
info: Add info attributes (HTML)
json: Emit JSON output
keys: Emit the key attribute for keys (XML)
log-gettext: Log (via stderr) each gettext(3) string lookup
log-syslog: Log (via stderr) each syslog message (via xo_syslog(3)) Ignore the {h:} modifier (TEXT, HTML)
no-locale: Do not initialize the locale setting
no-retain: Prevent retaining formatting information
no-top: Do not emit a top set of braces (JSON)
not-first: Pretend the 1st output item was not 1st (JSON)
pretty: Emit pretty-printed output
retain: Force retaining formatting information
text: Emit TEXT output Replace XML-friendly "-"s with JSON friendly "_"s e
units: Add the 'units' (XML) or 'data-units (HTML) attribute
warn: Emit warnings when libxo detects bad calls
warn-xml: Emit warnings in XML
xml: Emit XML output
xpath: Add XPath expressions (HTML)

The “brief-options” are single letter commands, designed for those with too little patience to use real tokens. No comma separator is used.

Token Action

H Enable HTML output (XO_STYLE_HTML)

I Enable info output (XOF_INFO)

i<num> Indent by <number>

J Enable JSON output (XO_STYLE_JSON)

P Enable pretty-printed output (XOF_PRETTY)

T Enable text output (XO_STYLE_TEXT)

W Enable warnings (XOF_WARN)

X Enable XML output (XO_STYLE_XML)

x Enable XPath data (XOF_XPATH)

The xo_set_program() function sets name of the program as reported by functions like xo_failure(), xo_warn(), xo_err(), etc. The program name is initialized by xo_parse_args(), but subsequent calls to xo_set_program() can override this value.

Note that the value is not copied, so the memory passed to xo_set_program() (and xo_parse_args()) must be maintained by the caller.

HISTORY

The libxo library first appeared in FreeBSD 11.0.

AUTHORS

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