libeconf - Man Page

Name

include/libeconf.h ā€” Public API for the econf library.
include/libeconf_ext.h ā€” Public extended API for the econf library.

Description

libeconf is a highly flexible and configurable library to parse and manage key=value configuration files.
It reads configuration file snippets from different directories and builds the final configuration file for the application from it.

The first file is the vendor provided configuration file.

There are two methods of overriding this vendor settings: Copy the file from /usr/_vendordir_ to /etc and modify the settings (see xample 1).

Alternatively, a directory named _file_._suffix_.d/ within /etc can be created, with drop-in files in the form _name_._suffix_ (see Example 2).

These files contain only the changes of the specific settings the user is interested in.
There can be several such drop-in files, they are processed in lexicographic order of their filename.

The first method is useful to override the complete configuration file with an own one, the vendor supplied configuration is ignored.

So, if /etc/_example_._suffix_ exists, /usr/_vendor_/_example_._suffix_ and /usr/_vendor_/_example_._suffix_.d/*._suffix_ will not be read.
The disadvantage is, that changes of the vendor configuration file, due e.g. an package update, are ignored and the user has to manually merge them.

The other method will continue to use /usr/_vendor_/_example_._suffix_ as base configuration file and merge all changes from /etc/_example_._suffix_.d/*._suffix_.
So the user will automatically get improvements of the vendor, with the drawback, that they could be incompatible with the user made changes.

Example 1

If a /etc/_example_._suffix_ files exists:

* /etc/_example_._suffix_

* /etc/_example_._suffix_.d/*._suffix_

Example 2

The list of files and directories read if **no** /etc/_example_._suffix_ file exists:

* /usr/_vendor_/_example_._suffix_

* /usr/_vendor_/_example_._suffix_.d/*._suffix_

* /etc/_example_._suffix_.d/*._suffix_

Synopsis

#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

Typedefs

typedef enum econf_err econf_err
typedef struct econf_file econf_file
typedef struct econf_ext_value econf_ext_value

Enumerations

enum econf_err { ECONF_SUCCESS = 0, ECONF_ERROR = 1, ECONF_NOMEM = 2, ECONF_NOFILE = 3, ECONF_NOGROUP = 4, ECONF_NOKEY = 5, ECONF_EMPTYKEY = 6, ECONF_WRITEERROR = 7, ECONF_PARSE_ERROR = 8, ECONF_MISSING_BRACKET = 9, ECONF_MISSING_DELIMITER = 10, ECONF_EMPTY_SECTION_NAME = 11, ECONF_TEXT_AFTER_SECTION = 12 }
libeconf error codes

Functions

econf_err econf_readFile (econf_file **result, const char *file_name, const char *delim, const char *comment)
Process the file of the given file_name and save its contents into key_file object.
econf_err econf_mergeFiles (econf_file **merged_file, econf_file *usr_file, econf_file *etc_file)
Merge the contents of two key_files objects.
econf_err econf_readDirs (econf_file **key_file, const char *usr_conf_dir, const char *etc_conf_dir, const char *project_name, const char *config_suffix, const char *delim, const char *comment)
Evaluating key/values of a given configuration by reading and merging all needed/available files in two different directories (normally in /usr/etc and /etc).
econf_err econf_readDirsHistory (econf_file ***key_files, size_t *size, const char *usr_conf_dir, const char *etc_conf_dir, const char *project_name, const char *config_suffix, const char *delim, const char *comment)
Evaluating key/values for every given configuration files in two different directories (normally in /usr/etc and /etc).
econf_err econf_newKeyFile (econf_file **result, char delimiter, char comment)
Create a new econf_file object.
econf_err econf_newIniFile (econf_file **result)
Create a new econf_file object in IniFile format.
econf_err econf_writeFile (econf_file *key_file, const char *save_to_dir, const char *file_name)
Write content of a econf_file struct to specified location.
char * econf_getPath (econf_file *kf)
Evaluating path name of the regarding configuration file.
econf_err econf_getGroups (econf_file *kf, size_t *length, char ***groups)
Evaluating all group entries.
econf_err econf_getKeys (econf_file *kf, const char *group, size_t *length, char ***keys)
Evaluating all keys.
econf_err econf_getIntValue (econf_file *kf, const char *group, const char *key, int32_t *result)
Evaluating int32 value for given group/key.
econf_err econf_getInt64Value (econf_file *kf, const char *group, const char *key, int64_t *result)
Evaluating int64 value for given group/key.
econf_err econf_getUIntValue (econf_file *kf, const char *group, const char *key, uint32_t *result)
Evaluating uint32 value for given group/key.
econf_err econf_getUInt64Value (econf_file *kf, const char *group, const char *key, uint64_t *result)
Evaluating uint64 value for given group/key.
econf_err econf_getFloatValue (econf_file *kf, const char *group, const char *key, float *result)
Evaluating float value for given group/key.
econf_err econf_getDoubleValue (econf_file *kf, const char *group, const char *key, double *result)
Evaluating double value for given group/key.
econf_err econf_getStringValue (econf_file *kf, const char *group, const char *key, char **result)
Evaluating string value for given group/key.
econf_err econf_getBoolValue (econf_file *kf, const char *group, const char *key, bool *result)
Evaluating bool value for given group/key.
econf_err econf_getIntValueDef (econf_file *kf, const char *group, const char *key, int32_t *result, int32_t def)
Evaluating int32 value for given group/key.
econf_err econf_getInt64ValueDef (econf_file *kf, const char *group, const char *key, int64_t *result, int64_t def)
Evaluating int64 value for given group/key.
econf_err econf_getUIntValueDef (econf_file *kf, const char *group, const char *key, uint32_t *result, uint32_t def)
Evaluating uint32 value for given group/key.
econf_err econf_getUInt64ValueDef (econf_file *kf, const char *group, const char *key, uint64_t *result, uint64_t def)
Evaluating uint64 value for given group/key.
econf_err econf_getFloatValueDef (econf_file *kf, const char *group, const char *key, float *result, float def)
Evaluating float value for given group/key.
econf_err econf_getDoubleValueDef (econf_file *kf, const char *group, const char *key, double *result, double def)
Evaluating double value for given group/key.
econf_err econf_getStringValueDef (econf_file *kf, const char *group, const char *key, char **result, char *def)
Evaluating string value for given group/key.
econf_err econf_getBoolValueDef (econf_file *kf, const char *group, const char *key, bool *result, bool def)
Evaluating bool value for given group/key.
econf_err econf_setIntValue (econf_file *kf, const char *group, const char *key, int32_t value)
Set int32 value for given group/key.
econf_err econf_setInt64Value (econf_file *kf, const char *group, const char *key, int64_t value)
Set int64 value for given group/key.
econf_err econf_setUIntValue (econf_file *kf, const char *group, const char *key, uint32_t value)
Set uint32 value for given group/key.
econf_err econf_setUInt64Value (econf_file *kf, const char *group, const char *key, uint64_t value)
Set uint64 value for given group/key.
econf_err econf_setFloatValue (econf_file *kf, const char *group, const char *key, float value)
Set float value for given group/key.
econf_err econf_setDoubleValue (econf_file *kf, const char *group, const char *key, double value)
Set double value for given group/key.
econf_err econf_setStringValue (econf_file *kf, const char *group, const char *key, const char *value)
Set string value for given group/key.
econf_err econf_setBoolValue (econf_file *kf, const char *group, const char *key, const char *value)
Set bool value for given group/key.
const char * econf_errString (const econf_err error)
Convert an econf_err type to a string.
void econf_errLocation (char **filename, uint64_t *line_nr)
Info about where the error has happened.
void econf_freeArray (char **array)
Free an array of type char** created by econf_getGroups() or econf_getKeys().
void econf_freeFile (econf_file *key_file)
Free memory allocated by e.g. econf_err econf_getExtValue (econf_file *kf, const char *group, const char *key, econf_ext_value **result) Evaluating more information for given group/key.
void econf_freeExtValue (econf_ext_value *to_free)
Free an complete econf_ext_value struct.

Detailed Description

Public API for the econf library.

Definition in file libeconf.h and libeconf_ext.h.

Typedef Documentation

typedef struct econf_file econf_file

Container which includes all information about the configuration file(s).

typedef struct econf_ext_value econf_ext_value

char ** values
Values of a given key in form of an string array.
char * file
Path of the configuration file where this value has been read.
uint64_t line_number
Line number of the configuration key/value.
char * comment_before_key
Comment before the key/value entry.
char * comment_after_value
Comment after the value entry.

Enumeration Type Documentation

enum econf_err

libeconf error codes

Enumerator

ECONF_SUCCESS

General purpose success code.

ECONF_ERROR

Generic Error.

ECONF_NOMEM

Out of memory.

ECONF_NOFILE

Config file not found.

ECONF_NOGROUP

Group not found.

ECONF_NOKEY

Key not found.

ECONF_EMPTYKEY

Key has empty value.

ECONF_WRITEERROR

Error creating or writing to a file.

ECONF_PARSE_ERROR

General syntax error in input file.

ECONF_MISSING_BRACKET

Missing closing section bracket.

ECONF_MISSING_DELIMITER

Missing delimiter.

ECONF_EMPTY_SECTION_NAME

Empty section name.

ECONF_TEXT_AFTER_SECTION

Text after section.

Function Documentation

econf_err econf_readFile (econf_file ** result, const char * file_name, const char * delim, const char * comment)

Process the file of the given file_name and save its contents into key_file object.

Parameters:

result content of parsed file
file_name absolute path of parsed file
delim delimiters of key/value e.g. '\t ='
comment array of characters which define the start of a comment

Returns:

econf_err ECONF_SUCCESS or error code

Usage:

#include "libeconf.h"

econf_file *key_file = NULL;
econf_err error;

error = econf_readFile (&key_file, "/etc/test.conf", "=", "#");

econf_free (key_file);

Default behaviour if entries have the same name in one file: The first hit will be returned. Further entries will be ignored. This can be changed by setting the environment variable ECONF_JOIN_SAME_ENTRIES. In that case entries with the same name will be joined to one single entry.

econf_err econf_readDirsHistory (econf_file *** key_files, size_t * size, const char * usr_conf_dir, const char * etc_conf_dir, const char * project_name, const char * config_suffix, const char * delim, const char * comment)

Evaluating key/values for every given configuration files in two different directories (normally in /usr/etc and /etc). Returns a list of read configuration files and their values.

Parameters:

key_files list of parsed file(s). Each entry includes all key/value, path, comments,... information of the regarding file.
size Size of the evaluated key_files list.
usr_conf_dir absolute path of the first directory (normally '/usr/etc')
etc_conf_dir absolute path of the second directory (normally '/etc')
project_name basename of the configuration file
config_suffix suffix of the configuration file. Can also be NULL.
delim delimiters of key/value e.g. '\t ='
comment array of characters which define the start of a comment

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_mergeFiles (econf_file ** merged_file, econf_file * usr_file, econf_file * etc_file)

Merge the contents of two key_files objects. Entries in etc_file will be prefered.

Parameters:

merged_file merged data
usr_file First data block which has to be merged.
etc_file Second data block which has to be merged.

Returns:

econf_err ECONF_SUCCESS or error code

Usage:

#include "libeconf.h"

econf_file *key_file_1 = NULL, *key_file_2 = NULL, *key_file_ret = NULL
econf_err error;

error = econf_readFile (&key_file1, "/usr/etc/test.conf", "=", "#");
error = econf_readFile (&key_file2, /etc/test.conf", "=", "#");
error = econf_mergeFiles (&key_file_ret, key_file_1, key_file_2);

econf_free (key_file_ret);
econf_free (key_file_1);
econf_free (key_file_2);

econf_err econf_readDirs (econf_file ** key_file, const char * usr_conf_dir, const char * etc_conf_dir, const char * project_name, const char * config_suffix, const char * delim, const char * comment)

Evaluating the content of a given configuration file by reading all needed/available files in two different directories (normally in /usr/etc and /etc).

Parameters:

key_file content of parsed file(s)
usr_conf_dir absolute path of the first directory (normally '/usr/etc')
etc_conf_dir absolute path of the second directory (normally '/etc')
project_name basename of the configuration file
config_suffix suffix of the configuration file. Can also be NULL.
delim delimiters of key/value e.g. '\t ='
comment array of characters which define the start of a comment

Returns:

econf_err ECONF_SUCCESS or error code

Example: Reading content of example.conf in /usr/etc and /etc directory.

#include "libeconf.h"

econf_file *key_file = NULL;
econf_err error;

error = econf_readDirs (&key_file,
                        "/usr/etc",
                        "/etc",
                        "example",
                        "conf",
                        "=", "#");

econf_free (key_file);

econf_err econf_newKeyFile (econf_file ** result, char delimiter, char comment)

Create a new econf_file object.

Parameters:

result Pointer to the allocated econf_file object.
delimiter delimiter of key/value e.g. '='
comment Character which defines the start of a comment.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_newIniFile (econf_file ** result)

Create a new econf_file object in IniFile format. So the delimiter will be '=' and comments are beginning with '#'.

Parameters:

result Pointer to the allocated econf_file object.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_writeFile (econf_file * key_file, const char * save_to_dir, const char * file_name)

Write content of a econf_file struct to specified location.

Parameters:

key_file Data which has to be written.
save_to_dir Directory into which the file has to be written.
file_name filename (with suffix)

Returns:

econf_err ECONF_SUCCESS or error code

char* econf_getPath (econf_file * kf)

Evaluating path name.

Parameters:

kf given/parsed data

Returns:

Absolute path name or an empty string if kf is a result of already merged data (e.G. returned by econf_readDirs).

econf_err econf_getGroups (econf_file * kf, size_t * length, char *** groups)

Evaluating all group entries.

Parameters:

kf given/parsed data
length Length of the returned group array.
groups String array of evaluated groups.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getKeys (econf_file * kf, const char * group, size_t * length, char *** keys)

Evaluating all keys.

Parameters:

kf given/parsed data
group Group name for which the keys have to be evaluated or NULL for all keys.
length Length of the returned key array.
keys String array of evaluated keys.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getIntValue (econf_file * kf, const char * group, const char * key, int32_t * result)

Evaluating int32 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getInt64Value (econf_file * kf, const char * group, const char * key, int64_t * result)

Evaluating int64 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getUIntValue (econf_file * kf, const char * group, const char * key, uint32_t * result)

Evaluating uint32 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getUInt64Value (econf_file * kf, const char * group, const char * key, uint64_t * result)

Evaluating uint64 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getFloatValue (econf_file * kf, const char * group, const char * key, float * result)

Evaluating float value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getDoubleValue (econf_file * kf, const char * group, const char * key, double * result)

Evaluating double value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getStringValue (econf_file * kf, const char * group, const char * key, char ** result)

Evaluating string value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result A newly allocated string or NULL in error case.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getBoolValue (econf_file * kf, const char * group, const char * key, bool * result)

Evaluating bool value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getIntValueDef (econf_file * kf, const char * group, const char * key, int32_t * result, int32_t def)

Evaluating int32 value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getInt64ValueDef (econf_file * kf, const char * group, const char * key, int64_t * result, int64_t def)

Evaluating int64 value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getUIntValueDef (econf_file * kf, const char * group, const char * key, uint32_t * result, uint32_t def)

Evaluating uint32 value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getUInt64ValueDef (econf_file * kf, const char * group, const char * key, uint64_t * result, uint64_t def)

Evaluating uint64 value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getFloatValueDef (econf_file * kf, const char * group, const char * key, float * result, float def)

Evaluating float value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getDoubleValueDef (econf_file * kf, const char * group, const char * key, double * result, double def)

Evaluating double value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getStringValueDef (econf_file * kf, const char * group, const char * key, char ** result, char * def)

Evaluating string value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result Returns a newly allocated string, even if 'default' is returned.
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_getBoolValueDef (econf_file * kf, const char * group, const char * key, bool * result, bool def)

Evaluating bool value for given group/key. If key is not found, the default value is returned and error is ECONF_NOKEY.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result determined value
def Default value if the value has not been found.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setIntValue (econf_file * kf, const char * group, const char * key, int32_t value)

Set int32 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setInt64Value (econf_file * kf, const char * group, const char * key, int64_t value)

Set int64 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setUIntValue (econf_file * kf, const char * group, const char * key, uint32_t value)

Set uint32 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setUInt64Value (econf_file * kf, const char * group, const char * key, uint64_t value)

Set uint64 value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setFloatValue (econf_file * kf, const char * group, const char * key, float value)

Set float value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setDoubleValue (econf_file * kf, const char * group, const char * key, double value)

Set double value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setStringValue (econf_file * kf, const char * group, const char * key, const char * value)

Set string value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

econf_err econf_setBoolValue (econf_file * kf, const char * group, const char * key, const char * value)

Set bool value for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value has to be set.
value Value which has to be set.

Returns:

econf_err ECONF_SUCCESS or error code

const char* econf_errString (const econf_err error)

Convert an econf_err type to a string.

Parameters:

error error enum

Returns:

human readable string

void econf_errLocation (char ** filename, uint64_t * line_nr)

Info about where the error has happened.

Parameters:

filename Path of the last scanned file.
line_nr Number of the last handled line.

void econf_freeArray (char ** array)

Free an array of type char** created by econf_getGroups() or econf_getKeys().

Parameters:

array array of strings

Returns:

void

void econf_freeFile (econf_file * key_file)

Free memory allocated by e.g. econf_readFile(), econf_readDirs(),...

Parameters:

key_file allocated data

Returns:

void

econf_err econf_getExtValue (econf_file * kf, const char * group, const char * key, econf_ext_value ** result)

Evaluating more information for given group/key.

Parameters:

kf given/parsed data
group Desired group or NULL if there is no group defined.
key Key for which the value is requested.
result A newly allocated struct or NULL in error case.

Returns:

econf_err ECONF_SUCCESS or error code

void econf_freeExtValue (econf_ext_value * to_free)

Free an complete econf_ext_value struct.

Parameters:

to_free struct which has to be freed

Returns:

void

See Also

econftool

Info

Thu Apr 8 2021 Version 0.4.0