NAME
figpar
,
parse_config
,
get_config_option
—
configuration file parsing
library
LIBRARY
library “libfigpar”
SYNOPSIS
#include
<figpar.h>
int
parse_config
(struct figpar_config
options[], const char *path, int
(*unknown)(struct figpar_config *option, uint32_t
line, char *directive, char
*value), uint8_t processing_options);
struct figpar_config *
get_config_option
(struct figpar_config
options[], const char *directive);
#include
<string_m.h>
int
replaceall
(char *source,
const char *find, const char
*replace);
unsigned int
strcount
(const char *source,
const char *find);
void
strexpand
(char *source);
void
strexpandnl
(char *source);
void
strtolower
(char *source);
DESCRIPTION
Thefigpar
library provides a light-weight, portable
framework for parsing configuration files. The library uses
open(2), read(2), and
lseek(2) within the file pointed to by path to
find directives and values which are then made available to the application.
Due to the fact that configuration files may have basic syntax differences, the library does not attempt to impose any structure on the data but instead provides raw data to a set of callback functions. These callback functions can in-turn initiate abort through their return value, allowing custom syntax validation during parsing.
Configuration directives, types, and callback functions are
provided through data structures defined in
<figpar.h>
:
struct figpar_config { enum figpar_cfgtype type; /* value type */ const char *directive; /* keyword */ union figpar_cfgvalue value; /* value */ /* Pointer to function used when directive is found */ int (*action)(struct figpar_config *option, uint32_t line, char *directive, char *value); }; enum figpar_cfgtype { FIGPAR_TYPE_NONE = 0x0000, /* directives with no value */ FIGPAR_TYPE_BOOL = 0x0001, /* boolean */ FIGPAR_TYPE_INT = 0x0002, /* signed 32 bit integer */ FIGPAR_TYPE_UINT = 0x0004, /* unsigned 32 bit integer */ FIGPAR_TYPE_STR = 0x0008, /* string pointer */ FIGPAR_TYPE_STRARRAY = 0x0010, /* string array pointer */ FIGPAR_TYPE_DATA1 = 0x0020, /* void data type-1 (open) */ FIGPAR_TYPE_DATA2 = 0x0040, /* void data type-2 (open) */ FIGPAR_TYPE_DATA3 = 0x0080, /* void data type-3 (open) */ FIGPAR_TYPE_RESERVED1 = 0x0100, /* reserved data type-1 */ FIGPAR_TYPE_RESERVED2 = 0x0200, /* reserved data type-2 */ FIGPAR_TYPE_RESERVED3 = 0x0400, /* reserved data type-3 */ }; union figpar_cfgvalue { void *data; /* Pointer to NUL-terminated string */ char *str; /* Pointer to NUL-terminated string */ char **strarray; /* Pointer to an array of strings */ int32_t num; /* Signed 32-bit integer value */ uint32_t u_num; /* Unsigned 32-bit integer value */ uint32_t boolean:1; /* Boolean integer value (0 or 1) */ };
The processing_options
argument to
parse_config
()
is a mask of bit fields which indicate various processing options. The
possible flags are:
FIGPAR_BREAK_ON_EQUALS
- An equals sign
(‘
’) is normally considered part of the directive. This flag enables terminating the directive at the equals sign. Also makes equals sign optional and transient.=
FIGPAR_BREAK_ON_SEMICOLON
- A semicolon
(‘
’) is normally considered part of the value. This flag enables terminating the value at the semicolon. Also allows multiple statements on a single line separated by semicolon.;
FIGPAR_CASE_SENSITIVE
- Normally directives are matched case insensitively using fnmatch(3). This flag enables directive matching to be case sensitive.
FIGPAR_REQUIRE_EQUALS
- If a directive is not followed by an equals, processing is aborted.
FIGPAR_STRICT_EQUALS
- Equals must be part of the directive to be considered a delimiter between directive and value.
The options struct array
pointer can be NULL and every directive will run the
unknown
()
function argument.
The directive for each figpar_config item in
the
parse_config
()
options argument is matched against each parsed directive using
fnmatch(3) until a match is found. If a match is found, the
action
()
function for that figpar_config directive is run with the line number,
directive, and value. Otherwise if no match, the
unknown
() function is run (with the same
arguments).
If either action or
unknown return non-zero,
parse_config
()
aborts reading the file and returns the error value to its caller.
get_config_option
()
traverses the options-array and returns the option that matches via
strcmp(3), or if no match a pointer to a static dummy struct is
returned (whose values are all zero or NULL).
The use of struct
figpar_config is entirely optional as-is the use of
enum figpar_cfgtype or union
figpar_cfgvalue. For example, a NULL pointer can be passed to
parse_config
()
for the first argument while providing a simple
unknown function based on
queue(3) that populates a singly-linked list of a struct containing
the directive and value.
In addition, miscellaneous string manipulation routines are
provided by
<string_m.h>
:
replaceall
()- Replace all occurrences of find in source with replace.
strcount
()- Count the number of occurrences of one string that appear in the
source string. Return value is the total count. An
example use would be to show how large a block of memory needs to be for a
replaceall
() series. strexpand
()- Expand escape sequences in a buffer pointed to by source.
strexpandnl
()- Expand only the escaped newlines in a buffer pointed to by source.
strtolower
()- Convert a string to lower case.
SEE ALSO
HISTORY
The figpar
library first appeared in
FreeBSD 10.2.
AUTHORS
Devin Teske ⟨dteske@FreeBSD.org⟩
BUGS
This is the first implementation of the library, and the interface may be subject to refinement.