After a libcfg+ context is created and its flags are set (optional), one can initiate the parsing. This chapter provides information about the available parsing methods.
These functions take a context as their only argument. Depending on the type
of the context, either a file or a command line option will be processed. If
the option just parsed matches one of the options in the option set
(see Options set section) and the arguments of the
parsed option are stored in memory and value
is set
to point to them. However, if the value
of the
relevant option in the option is set to NULL
, the
arguments will not be stored.
The main and only difference between the two functions is in the way they
interpret the val
field of the relevant option
after a matching token was found in the token stream. The function
cfg_get_next_opt()
respects the value of this field and
if it is not 0
, returns the value upon a match. If the
field is set to 0
, the function proceeds to the next token
without returning a value. In the case of cfg_parse()
,
val
is ignored.
If an error occurs during parsing, the functions return a negative integer.
This is why it is a good idea to set the val
member
of the cfg_option
to a value equal or greater than
0
. Detailed information about error codes as well as
their descriptions can be found in the Error handling section.
At the end of parsing 0
is returned.
The following functions provide additional information about a matched option.
#include <cfg+.h>
char *cfg_get_cur_opt
(const CFG_CONTEXT con);
char *cfg_get_cur_arg
(const CFG_CONTEXT con);
int cfg_get_cur_idx
(const CFG_CONTEXT con);
Use cfg_get_cur_opt()
to get the name of the option being
processed. Use cfg_get_cur_arg()
to get the current
argument. Finally, use cfg_get_cur_idx()
to get the
current offset in the parsing stream. If the context is associated with the
command line, the value is the current offset in the
argv
array. If the context is associated with a
configuration file, then depending on the value of
CFG_FILE_LINE_POS_USAGE
, it is either the current byte
offset or line number in the file.