NAME

       rgxg_number_range, rgxg_number_greaterequal - create regex that matches integers in the given range

SYNOPSIS

       #include <rgxg/number.h>

       int rgxg_number_range (long long first, long long last, int base,
            size_t min_length, char *regex, rgxg_options_t options);

       int rgxg_number_greaterequal (long long number, int base,
            size_t min_length, char *regex, rgxg_options_t options);

DESCRIPTION

       rgxg_number_range()  generates  the  (extended)  regular  expression  that  matches integers in the range
       between first and last.

       rgxg_number_greaterequal() generates the (extended) regular expression that matches integers greater than
       or equal to number.

       The  base  of  the  matched integers is specified by base, which must be between 2 and 32 inclusive. Note
       that for bases greater than 16 the "extended hex" alphabet is used  (referenced  as  'base32hex'  in  RFC
       4648).

       If  RGXG_LEADINGZERO  or  RGXG_VARLEADINGZERO is set, then min_length specifies the minimum length of the
       matched integers (otherwise the argument is ignored). For instance the number 5 with min_length set to  3
       and  options  set to RGXG_LEADINGZERO is matched as '005'. By default the number of leading zeros depends
       on the length of the last number. If min_length is lesser than or equal to the number of digits of  last,
       the value has no effect.

       The generated regular expression is written to the character string regex, including the terminating null
       byte ('\0'), unless RGXG_NONULLBYTE is set. If regex is NULL the return value is the number of characters
       (excluding  the  terminating  null byte) that would have been written in case regex has been initialized.
       Note that the functions assume an arbitrarily long regex string,  callers  must  ensure  that  the  given
       string is large enough to not overflow the actual space.

       options is either zero, or the bitwise-or of one or more of the following macros:

       RGXG_NOUPPERCASE
              The  generated regular expression only matches lower case letters for base values greater than 10.
              The default is to match both lower and upper case letters.

       RGXG_NOLOWERCASE
              The generated regular expression only matches upper case letters for base values greater than  10.
              The default is to match both lower and upper case letters.

       RGXG_NOOUTERPARENS
              Omit the outer parenthesis, if any, of the regular expression.

       RGXG_LEADINGZERO
              The  generated  regular expression only matches integers with leading zeros (e.g. the integer 5 is
              only matched as '005'). The number of leading zeros is influenced by the min_length argument  (see
              above). By default no leading zeros are matched.

       RGXG_VARLEADINGZERO
              The  generated  regular  expression matches integers with a variable number of leading zeros (e.g.
              the number 5 is matched as '5', '05' and '005'). The maximum number of leading zeros is influenced
              by the min_length argument (see above). By default no leading zeros are matched.

       RGXG_NONULLBYTE
              Do not add the terminating null byte ('\0') to the regex string.

       Note  that  RGXG_NOUPPERCASE and RGXG_NOLOWERCASE as well as RGXG_LEADINGZERO and RGXG_VARLEADINGZERO are
       mutual exclusive options.

RETURN VALUE

       Upon successful return, these functions return the number of characters (excluding the  terminating  null
       byte) written to regex.

       If an error occurs, a (negative) error code is returned (see ERRORS section).

ERRORS

       The following errors can be returned:

       RGXG_ERROR_RANGE (rgxg_number_range() only)
              Invalid range (e.g.  first number is greater than last number).

       RGXG_ERROR_BASE
              The base is lesser than 2 or greater than 32.

       RGXG_ERROR_NEGARG
              At least one argument is negative.

       RGXG_ERROR_ARG2BIG (rgxg_number_greaterequal() only)
              The value of number is too large.

       RGXG_ERROR_MUTEXOPTIONS
              Two mutual exclusive options were specified.

AVAILABILITY

       These functions are available since rgxg 0.1.

SEE ALSO

       regex(7), rgxg_net_cidr_ipv4(3), rgxg_net_cidr_ipv6(3), rgxg_net_cidr_string(3).

AUTHOR

       Hannes von Haugwitz <hannes@vonhaugwitz.com>