Mu supports several option types, and more may be added in the
future. These types will automatically be processed from the string
argument, and the processed argument will be returned in *arg if
arg is not NULL (see Option Structure). arg
should be a pointer to a value of the type indicated by the
arg_type field, which must be one of the values in the table
below. However, if arg_type is MU_OPT_SUBOPT, arg
must not be used (see Parsing Suboptions). If an error occurs while
processing an argument, an error message will be printed to standard
error, and mu_parse_opts will return an error code (see Option Parsing Errors).
Unless otherwise specified, *argstr will be set to the
unprocessed string argument if argstr is not NULL
(see Option Structure). However, if arg_type is
MU_OPT_SUBOPT, argstr must not be used.
You can also parse your own types using callbacks (see Option Callbacks).
MU_OPT_BOOL ¶This is a boolean value. The type of *arg should be int
and bool_default should be used for the default value
(see Option Structure). If MU_OPT_BOOL is given in the
arg_type field, the argument can either be ‘yes’ or
‘true’ for a true value, or ‘no’ or ‘false’ for a false
value. Matching is case insensitive and allows abbreviation.
If the argument is none of ‘yes’, ‘no’, ‘true’, or ‘false’, it will be parsed as an integer (see below). Zero is false and any other integer is true.
If the argument is not an integer either, that will be an error.
MU_OPT_INT ¶This is an integer value. The type of *arg should be long
and int_default should be used for the default value
(see Option Structure). The radix (or base) that the argument is
parsed as depends on the first non-whitespace characters after an
optional ‘+’ or ‘-’ sign. If these characters are ‘0x’ or
‘0X’, the integer is parsed as hexadecimal. Otherwise, if the first
character is ‘0’, and the following character is not
‘x’ or ‘X’, the integer will be parsed as octal. Otherwise,
the integer will be parsed as decimal. See (libc)Parsing of Integers for more information on how integers are parsed.
If the parsed integer is outside the bounds specified by the
ibound field (see Option Structure), then that will be
treated as an error.
MU_OPT_FLOAT ¶This is a floating-point value. The type of *arg should be
double and float_default should be used for the default
value (see Option Structure). The radix (or base) that the argument
is parsed as depends on the first non-whitespace characters after an
optional ‘+’ or ‘-’ sign. If these characters are ‘0x’ or
‘0X’, the number is parsed as hexadecimal. Otherwise, if the first
character is ‘0’, and the following character is not
‘x’ or ‘X’, the number will be parsed as octal. Otherwise, the
number will be parsed as decimal. See (libc)Parsing of Floats for
more information on how floating-point numbers are parsed.
See (libc)Parsing of Floats for more information on how
floating-point numbers are parsed.
If the parsed floating-point numebr is outside the bounds specified by
the fbound field (see Option Structure), then that will be
treated as an error.
MU_OPT_STRING ¶This is a string value. The type of *arg should be const
char * and string_default should be used for the default value
(see Option Structure) (i.e., the type of arg should be
const char **). *argstr (if argstr is not
NULL) will be set to the same value as *arg.
MU_OPT_FILE ¶This is a file argument. The type of *arg should be FILE *
(i.e., the type of arg should be FILE **) and
file_default should be used for the default value (see Option Structure). file_mode should be used for this type and only for
this type (see Option Structure).
file_mode describes the mode to use when opening the file, and
how ‘-’ should be handled. If file_mode indicates that the
file should be opened in read-only mode, ‘-’ will be handled as
standard input. If file_mode indicates that the file should be
opened in write-only mode, ‘-’ will be handled as standard
output. If file_mode indicates that the file should be opened for
both reading and writing, ‘-’ will cause an error.
If argstr is not NULL, *argstr will be set to
‘<stdin>’ if ‘-’ was handled as standard input,
‘<stdout>’ if ‘-’ was handled as standard output, or the file
name given as the argument to the option if the argument was not
‘-’.
If an error occurs while opening a file, an error message will be
printed to standard error and mu_parse_opts will return an error
code (see Option Parsing Errors).
For more information on how files are opened and how file_mode is
parsed, see (libc)Opening Streams.
MU_OPT_DIRECTORY ¶This is a directory argument. The type of *arg should be
DIR * (i.e., the type of arg should be DIR **) and
dir_default should be used for the default value (see Option Structure). See (libc)Opening a Directory Stream for more
information on how directories are opened.
If you’d like to know the name of the directory as given as the argument
to the option, you can use the argstr field (see Option Structure).
If an error occurs while opening a directory, an error message will be
printed to standard error and mu_parse_opts will return an error
code (see Option Parsing Errors).
MU_OPT_ENUM ¶This is an enumerated argument. The enumeration specification is the
enum_values field (see Option Structure).
For more information, See Parsing Enumerated Arguments to Options.
MU_OPT_SUBOPT ¶This indicates that the option takes suboptions as arguments. Suboptions may not take suboptions as arguments. See Parsing Suboptions for more information.