JSON

Jansson helpers: load and dump JSON, copy/merge objects, traverse trees, and convert between JSON values and common C types.

Source code:

`anystring2json()`¶

Converts a given string into a JSON object, supporting various formats including arrays and objects. Returns NULL if parsing fails.

json_t *anystring2json(
    const char *bf,
    size_t len,
    BOOL verbose
);

Parameters

Key	Type	Description
`bf`	`const char *`	The input string to be converted into a JSON object.
`len`	`size_t`	The length of the input string.
`verbose`	`BOOL`	If TRUE, logs errors when parsing fails.

Returns

Returns a json_t * representing the parsed JSON object, or NULL if parsing fails.

Notes

Uses json_loadb() with JSON_DECODE_ANY to support multiple JSON formats. If verbose is TRUE, logs errors when parsing fails.

`bits2gbuffer()`¶

Converts a bitmask into a gbuffer_t structure containing a string representation of the set bits, separated by ‘|’.

gbuffer_t *bits2gbuffer(
    const char **strings_table,
    uint64_t bits
);

Parameters

Key	Type	Description
`strings_table`	`const char **`	An array of strings representing bit names, terminated by a NULL pointer.
`bits`	`uint64_t`	A bitmask where each set bit corresponds to an index in `strings_table`.

Returns

A newly allocated gbuffer_t * containing the string representation of the set bits, or NULL if memory allocation fails.

Notes

The caller is responsible for managing the memory of the returned gbuffer_t * using gbuffer_decref().

`bits2jn_strlist()`¶

Converts a bitmask into a JSON list of corresponding string representations based on a provided lookup table.

json_t *bits2jn_strlist(
    const char **strings_table,
    uint64_t bits
);

Parameters

Key	Type	Description
`strings_table`	`const char **`	An array of string literals representing bit positions, terminated by a NULL pointer.
`bits`	`uint64_t`	A bitmask where each set bit corresponds to an index in `strings_table`.

Returns

A JSON array containing the string representations of the set bits in bits. The caller is responsible for managing the returned JSON object.

Notes

The function iterates through the strings_table and checks each bit in bits. If a bit is set, the corresponding string is added to the JSON array.

`cmp_two_simple_json()`¶

cmp_two_simple_json() compares two JSON values that are either strings, integers, reals, or booleans. It returns a value indicating their relative order.

int cmp_two_simple_json(
    json_t *jn_var1,  // not owned
    json_t *jn_var2   // not owned
);

Parameters

Key	Type	Description
`jn_var1`	`json_t *`	The first JSON value to compare. Must be a string, integer, real, or boolean.
`jn_var2`	`json_t *`	The second JSON value to compare. Must be a string, integer, real, or boolean.

Returns

Returns -1 if jn_var1 is less than jn_var2, 0 if they are equal, and 1 if jn_var1 is greater than jn_var2. If either value is a complex JSON type (object or array), they are considered equal.

Notes

This function does not compare JSON objects or arrays. It first attempts to compare as real numbers, then as integers, then as booleans, and finally as strings if necessary.

`create_json_record()`¶

create_json_record() initializes a JSON object based on a predefined schema, setting default values for each field.

json_t *create_json_record(
    hgobj gobj,
    const json_desc_t *json_desc
);

Parameters

Key	Type	Description
`gobj`	`hgobj`	A handle to the GObj instance, used for logging errors.
`json_desc`	`const json_desc_t *`	A pointer to an array of `json_desc_t` structures defining the JSON schema.

Returns

A newly allocated json_t * object containing the initialized JSON structure, or NULL on failure.

Notes

[‘The json_desc_t structure must be properly terminated with a NULL entry.’, ‘The function supports various JSON types including string, integer, real, boolean, null, object, and array.’, ‘If an unknown type is encountered, an error is logged using gobj_log_error().’]

`debug_json()`¶

Prints a JSON object with its reference counts, providing a structured view of its contents.

int debug_json(
    const char *label,
    json_t *jn,
    BOOL verbose
);

Parameters

Key	Type	Description
`label`	`const char *`	A label to prefix the output, used for identification.
`jn`	`json_t *`	The JSON object to be printed, must not be NULL.
`verbose`	`BOOL`	If TRUE, prints detailed information including indentation.

Returns

Returns 0 on success, or -1 if the JSON object is NULL or has an invalid reference count.

Notes

This function is useful for debugging JSON structures by displaying their contents and reference counts.

`get_real_precision()`¶

Retrieves the current precision setting for real number representation in JSON encoding.

int get_real_precision(void);

Parameters

Key	Type	Description
`-`	`-`	This function does not take any parameters.

Returns

Returns the current precision value used for encoding real numbers in JSON.

Notes

This function is useful for checking the precision setting before modifying it with set_real_precision().

`jn2bool()`¶

The function jn2bool converts a JSON value to a boolean representation, interpreting various JSON types accordingly.

BOOL jn2bool(json_t *jn_var);

Parameters

Key	Type	Description
`jn_var`	`json_t *`	A pointer to a JSON value to be converted to a boolean.

Returns

Returns TRUE if the JSON value represents a truthy value, otherwise returns FALSE. Specifically, true JSON values return TRUE, false and null return FALSE, numbers return TRUE if nonzero, and strings return TRUE if non-empty.

Notes

This function is useful for safely interpreting JSON values as boolean flags. It ensures that various JSON types are correctly mapped to boolean values.

`jn2integer()`¶

jn2integer() converts a JSON value to an integer, handling different JSON types such as strings, booleans, and numbers.

json_int_t jn2integer(json_t *jn_var);

Parameters

Key	Type	Description
`jn_var`	`json_t *`	The JSON value to be converted to an integer.

Returns

Returns the integer representation of the JSON value. If the value is a string, it is parsed as an integer. If it is a boolean, true is converted to 1 and false to 0. If the value is null, it returns 0.

Notes

This function supports parsing integers from strings with decimal, octal (prefix 0), and hexadecimal (prefix x or X) formats.

`jn2real()`¶

The function jn2real converts a JSON numeric value to a double-precision floating-point number. It supports JSON integers, real numbers, strings representing numbers, and boolean values.

double jn2real(json_t *jn_var);

Parameters

Key	Type	Description
`jn_var`	`json_t *`	A pointer to a JSON value that will be converted to a double. It can be an integer, real, string, boolean, or null.

Returns

Returns the double representation of the JSON value. If the input is null, it returns 0.0.

Notes

If jn_var is a string, it is converted using atof(). Boolean values are mapped to 1.0 (true) and 0.0 (false).

`jn2string()`¶

jn2string() converts a JSON value into a dynamically allocated string representation, ensuring proper memory management.

char *jn2string(json_t *jn_var);

Parameters

Key	Type	Description
`jn_var`	`json_t *`	The JSON value to be converted into a string.

Returns

A dynamically allocated string representation of the JSON value. The caller must free the returned string using GBMEM_FREE().

Notes

If jn_var is a string, it returns a duplicate of the string. If it is an integer or real, it converts the value to a string. If it is a boolean, it returns “1” for true and “0” for false.

`json2str()`¶

json2str converts a JSON object into a formatted string with indentation.

char *json2str(
    const json_t *jn
);

Parameters

Key	Type	Description
`jn`	`const json_t *`	The JSON object to be converted into a string.

Returns

A newly allocated string containing the formatted JSON representation. The caller must free the returned string using gbmem_free().

Notes

The function uses JSON_INDENT(4) for formatting and JSON_REAL_PRECISION(get_real_precision()) to control floating-point precision.

`json2uglystr()`¶

json2uglystr converts a JSON object into a compact, non-tabular string representation.

char *json2uglystr(const json_t *jn);

Parameters

Key	Type	Description
`jn`	`const json_t *`	A pointer to the JSON object to be converted.

Returns

A dynamically allocated string containing the compact JSON representation. The caller must free the returned string using gbmem_free().

Notes

This function uses JSON_COMPACT and JSON_ENCODE_ANY flags to generate a minimal JSON string without indentation.

`json_check_refcounts()`¶

Checks the reference counts of a JSON object and its nested elements, ensuring they do not exceed a specified limit.

int json_check_refcounts(
    json_t *kw,
    int max_refcount,
    int *result
);

Parameters

Key	Type	Description
`kw`	`json_t *`	The JSON object to check. It is not owned by the function.
`max_refcount`	`int`	The maximum allowed reference count for any JSON element. If set to a positive value, elements exceeding this limit will be reported.
`result`	`int *`	Pointer to an integer that stores the result of the check. It must be initialized to 0 before calling the function.

Returns

Returns 0 if all reference counts are within the allowed limit. Returns a negative value if any reference count is invalid or exceeds the specified limit.

Notes

This function recursively checks all elements in the JSON object, including arrays and nested objects. If max_refcount is greater than 0, elements exceeding this limit will be logged as errors.

`json_config()`¶

The json_config function merges multiple JSON configuration sources into a single JSON string, allowing for variable substitution and expansion. It processes fixed, variable, file-based, and parameter-based configurations in a structured order.

json_t *json_config(
    BOOL print_verbose_config,
    BOOL print_final_config,
    const char *fixed_config,
    const char *variable_config,
    const char *config_json_file,
    const char *parameter_config,
    pe_flag_t quit
);

Parameters

Key	Type	Description
`print_verbose_config`	`BOOL`	If `TRUE`, prints the verbose configuration and exits.
`print_final_config`	`BOOL`	If `TRUE`, prints the final merged configuration and exits.
`fixed_config`	`const char *`	A fixed JSON configuration string that cannot be modified.
`variable_config`	`const char *`	A JSON configuration string that can be modified.
`config_json_file`	`const char *`	A file path containing JSON configuration data.
`parameter_config`	`const char *`	A JSON string containing additional configuration parameters.
`quit`	`pe_flag_t`	Determines the behavior on error, such as exiting or continuing execution.

Returns

Returns a dynamically allocated JSON string containing the merged configuration. The caller must free the returned string using jsonp_free().

Notes

[‘The function processes configurations in the following order: fixed_config, variable_config, config_json_file, and parameter_config.’, ‘If print_verbose_config or print_final_config is TRUE, the function prints the configuration and exits.’, ‘The function supports variable substitution using the __json_config_variables__ key.’, ‘The JSON string can contain one-line comments using ##^.’, ‘If an error occurs in JSON parsing, the function may exit based on the quit parameter.’]

`json_desc_to_schema()`¶

Converts a JSON record descriptor into a topic schema, mapping field definitions to a structured format.

json_t *json_desc_to_schema(
    const json_desc_t *json_desc
);

Parameters

Key	Type	Description
`json_desc`	`const json_desc_t *`	Pointer to an array of JSON field descriptors, defining the structure of the record.

Returns

A new JSON array containing schema definitions for each field in the input descriptor.

Notes

Each field in the schema includes an ‘id’, ‘header’, ‘type’, and ‘fillspace’ attribute. The caller is responsible for managing the returned JSON object.

`json_is_identical()`¶

The function json_is_identical() compares two JSON objects and returns TRUE if they are identical, otherwise FALSE.

BOOL json_is_identical(
    json_t *kw1,
    json_t *kw2
);

Parameters

Key	Type	Description
`kw1`	`json_t *`	The first JSON object to compare. It is not owned by the function.
`kw2`	`json_t *`	The second JSON object to compare. It is not owned by the function.

Returns

Returns TRUE if kw1 and kw2 are identical, otherwise returns FALSE.

Notes

The function converts both JSON objects to their string representations and compares them. It ensures deep comparison of JSON structures.

`json_list_str_index()`¶

The function json_list_str_index() searches for a string in a JSON array and returns its index if found, or -1 if not found.

int json_list_str_index(
    json_t *jn_list,
    const char *str,
    BOOL ignore_case
);

Parameters

Key	Type	Description
`jn_list`	`json_t *`	A JSON array to search within.
`str`	`const char *`	The string to search for in the JSON array.
`ignore_case`	`BOOL`	If `TRUE`, the search is case-insensitive; otherwise, it is case-sensitive.

Returns

Returns the index of the string in the JSON array if found, or -1 if not found.

Notes

The function expects jn_list to be a JSON array. If jn_list is not an array, an error is logged.

`json_print_refcounts()`¶

Prints the reference counts of a JSON object and its nested elements recursively.

int json_print_refcounts(
    json_t *jn,
    int level
);

Parameters

Key	Type	Description
`jn`	`json_t *`	The JSON object whose reference counts will be printed. It is not owned by the function.
`level`	`int`	The indentation level for formatting the output.

Returns

Returns 0 on success.

Notes

This function is useful for debugging memory management issues related to JSON reference counts.

`json_str_in_list()`¶

Checks if a given string exists within a JSON array of strings.

BOOL json_str_in_list(
    hgobj gobj,
    json_t *jn_list,
    const char *str,
    BOOL ignore_case
);

Parameters

Key	Type	Description
`gobj`	`hgobj`	A handle to the gobj instance, used for logging errors.
`jn_list`	`json_t *`	A JSON array containing string elements to be searched.
`str`	`const char *`	The string to search for within the JSON array.
`ignore_case`	`BOOL`	If TRUE, the comparison is case-insensitive; otherwise, it is case-sensitive.

Returns

Returns TRUE if the string is found in the JSON array, otherwise returns FALSE.

Notes

If jn_list is not a JSON array, an error is logged using gobj_log_error().

`load_json_from_file()`¶

The function load_json_from_file() loads a JSON object from a file located in the specified directory. It returns a parsed JSON object if successful, or NULL if the file does not exist or an error occurs.

json_t *load_json_from_file(
    hgobj gobj,
    const char *directory,
    const char *filename,
    log_opt_t on_critical_error
);

Parameters

Key	Type	Description
`gobj`	`hgobj`	A handle to a GObj, used for logging errors.
`directory`	`const char *`	The directory where the JSON file is located.
`filename`	`const char *`	The name of the JSON file to be loaded.
`on_critical_error`	`log_opt_t`	Logging options to handle critical errors.

Returns

Returns a json_t * object containing the parsed JSON data if successful, or NULL if the file does not exist or an error occurs.

Notes

The function uses json_loadfd() to parse the JSON file. If the file does not exist, it returns NULL without logging an error. If an error occurs while opening or parsing the file, it logs an error message using gobj_log_critical().

`load_persistent_json()`¶

The function load_persistent_json() loads a JSON object from a file in a specified directory. It supports exclusive access by keeping the file open if requested.

json_t *load_persistent_json(
    hgobj gobj,
    const char *directory,
    const char *filename,
    log_opt_t on_critical_error,
    int *pfd,
    BOOL exclusive,
    BOOL silence
);

Parameters

Key	Type	Description
`gobj`	`hgobj`	A handle to the gobj (generic object) that is requesting the JSON load.
`directory`	`const char *`	The directory where the JSON file is located.
`filename`	`const char *`	The name of the JSON file to be loaded.
`on_critical_error`	`log_opt_t`	Logging options to handle critical errors during file operations.
`pfd`	`int *`	Pointer to an integer where the file descriptor will be stored if `exclusive` is `TRUE`. If `exclusive` is `FALSE`, the file is closed after reading.
`exclusive`	`BOOL`	If `TRUE`, the file remains open and its descriptor is stored in `pfd`. If `FALSE`, the file is closed after reading.
`silence`	`BOOL`	If `TRUE`, suppresses error logging when the file does not exist.

Returns

Returns a json_t * representing the loaded JSON object. Returns NULL if the file does not exist or if an error occurs.

Notes

If exclusive is TRUE, the caller is responsible for closing the file descriptor stored in pfd. The function logs errors unless silence is TRUE and on_critical_error is set to LOG_NONE.

`print_json()`¶

Prints a JSON object to stdout with indentation and a label.

int print_json(
    const char *label,
    json_t *jn
);

Parameters

Key	Type	Description
`label`	`const char *`	A label to print before the JSON output.
`jn`	`json_t *`	The JSON object to print.

Returns

Returns 0 on success, or -1 if the JSON object is NULL or has an invalid reference count.

Notes

Uses json_dumpf() to print the JSON object with indentation.

`save_json_to_file()`¶

The function save_json_to_file() saves a JSON object to a file, creating the directory if necessary and applying the specified permissions.

int save_json_to_file(
    hgobj gobj,
    const char *directory,
    const char *filename,
    int xpermission,
    int rpermission,
    log_opt_t on_critical_error,
    BOOL create,
    BOOL only_read,
    json_t *jn_data
);

Parameters

Key	Type	Description
`gobj`	`hgobj`	The GObj context, used for logging and error handling.
`directory`	`const char *`	The directory where the JSON file will be saved.
`filename`	`const char *`	The name of the JSON file to be created or overwritten.
`xpermission`	`int`	The permission mode for the directory (e.g., 02770).
`rpermission`	`int`	The permission mode for the file (e.g., 0660).
`on_critical_error`	`log_opt_t`	Logging options for handling critical errors.
`create`	`BOOL`	If `TRUE`, the function will create the directory and file if they do not exist.
`only_read`	`BOOL`	If `TRUE`, the file will be set to read-only mode after writing.
`jn_data`	`json_t *`	The JSON object to be saved to the file. This parameter is owned by the function.

Returns

Returns 0 on success, or -1 if an error occurs.

Notes

The function ensures that the directory exists before saving the file. If only_read is TRUE, the file permissions are set to read-only after writing.

`set_real_precision()`¶

Sets the precision for real number formatting in JSON encoding and returns the previous precision value.

int set_real_precision(int precision);

Parameters

Key	Type	Description
`precision`	`int`	The new precision value for real number formatting.

Returns

Returns the previous precision value before the update.

Notes

This function affects the precision of floating-point numbers when converting JSON objects to strings.

`string2json()`¶

string2json converts a legal JSON string into a json_t object. The input string must be a valid JSON array ([]) or object ({}).

json_t *string2json(
    const char *str,
    BOOL verbose
);

Parameters

Key	Type	Description
`str`	`const char *`	A null-terminated string containing a valid JSON object or array.
`verbose`	`BOOL`	If `TRUE`, logs errors when parsing fails.

Returns

Returns a json_t * object if parsing is successful. Returns NULL if parsing fails.

Notes

[‘This function only accepts JSON objects ({}) or arrays ([]).’, ‘For more flexible JSON parsing, use anystring2json().’, ‘The returned json_t * must be freed using json_decref() to avoid memory leaks.’]

`strings2bits()`¶

Converts a delimited string of names into a bitmask based on a predefined string table.

uint64_t strings2bits(
    const char **strings_table,
    const char *str,
    const char *separators
);

Parameters

Key	Type	Description
`strings_table`	`const char **`	A null-terminated array of strings representing bit positions.
`str`	`const char *`	A string containing names separated by the specified delimiters.
`separators`	`const char *`	A string containing delimiter characters used to split `str`. Defaults to "\|, " if NULL or empty.

Returns

A 64-bit bitmask where each bit corresponds to a matched string in strings_table.

Notes

[‘Each string in str is matched against strings_table, and the corresponding bit is set in the returned bitmask.’, ‘If separators is NULL or empty, the default separators "|, " are used.’, ‘The function assumes that strings_table contains at most 64 entries, as it maps each entry to a bit in a uint64_t.’]

`anyfile2json()`¶

Loads a JSON object from a file at the specified path.

json_t *anyfile2json(
    const char *path,
    BOOL verbose
);

Parameters

Key	Type	Description
`path`	`const char *`	The file path to load the JSON data from.
`verbose`	`BOOL`	If TRUE, logs errors when the file cannot be opened or parsed.

Returns

Returns a json_t * representing the parsed JSON object, or NULL if the file cannot be opened or parsing fails.

`debug_json2()`¶

Prints a JSON object with a formatted prefix label, along with its reference counts.

int debug_json2(
    json_t *jn,
    const char *format,
    ...)JANSSON_ATTRS((format(printf, 2, 3))
);

Parameters

Key	Type	Description
`jn`	`json_t *`	The JSON object to be printed.
`format`	`const char *`	A printf-style format string used to build the prefix label.
`...`	variadic	Additional arguments for the format string.

Returns

Returns 0 on success, or -1 if the JSON object is NULL.

`is_metadata_key()`¶

Checks if a key is a metadata key by verifying it has exactly two leading underscores.

BOOL is_metadata_key(
    const char *key
);

Parameters

Key	Type	Description
`key`	`const char *`	The key string to check.

Returns

Returns TRUE if the key starts with __, otherwise returns FALSE.

`is_private_key()`¶

Checks if a key is a private key by verifying it has exactly one leading underscore.

BOOL is_private_key(
    const char *key
);

Parameters

Key	Type	Description
`key`	`const char *`	The key string to check.

Returns

Returns TRUE if the key starts with a single _, otherwise returns FALSE.

`json_config_string2json()`¶

Converts a JSON configuration string into a JSON object, with support for inline comment removal (using ##^ delimiter).

json_t *json_config_string2json(
    const char *bf,
    BOOL verbose
);

Parameters

Key	Type	Description
`bf`	`const char *`	The JSON configuration string to parse. May contain inline comments delimited by `##^`.
`verbose`	`BOOL`	If TRUE, logs errors when parsing fails.

Returns

Returns a json_t * representing the parsed JSON object, or NULL if parsing fails.

`json_dict_recursive_update()`¶

Recursively updates a JSON object with key-value pairs from another object.

int json_dict_recursive_update(
    json_t *object,
    json_t *other,
    BOOL overwrite
);

Parameters

Key	Type	Description
`object`	`json_t *`	The target JSON object to be updated.
`other`	`json_t *`	The source JSON object whose key-value pairs will be merged into `object`.
`overwrite`	`BOOL`	If TRUE, existing keys in `object` are overwritten with values from `other`. If FALSE, existing keys are preserved.

Returns

Returns 0 on success, or -1 if either parameter is not a JSON object.

`json_is_range()`¶

Checks if a JSON array represents a valid integer range (exactly two integers where first <= second).

BOOL json_is_range(
    json_t *list,
    json_int_t *pfirst,
    json_int_t *psecond
);

Parameters

Key	Type	Description
`list`	`json_t *`	The JSON array to check. Must contain exactly two integer elements.
`pfirst`	`json_int_t *`	If not NULL, receives the first (lower) value of the range.
`psecond`	`json_int_t *`	If not NULL, receives the second (upper) value of the range.

Returns

Returns TRUE if the array contains exactly two integers where the first is less than or equal to the second, otherwise returns FALSE.

`json_list_find()`¶

Searches for a JSON value in a JSON array and returns its index.

int json_list_find(
    json_t *list,
    json_t *value
);

Parameters

Key	Type	Description
`list`	`json_t *`	The JSON array to search within.
`value`	`json_t *`	The JSON value to search for.

Returns

Returns the index of the value in the array if found, or -1 if not found.

`json_list_int()`¶

Retrieves an integer value from a JSON array at the specified index.

json_int_t json_list_int(
    json_t *jn_list,
    size_t idx
);

Parameters

Key	Type	Description
`jn_list`	`json_t *`	The JSON array to retrieve the value from.
`idx`	`size_t`	The index of the element to retrieve.

Returns

Returns the integer value at the specified index, or 0 if the index is out of bounds or the element is not an integer.

`json_list_int_index()`¶

Searches for an integer value in a JSON array and returns its index.

int json_list_int_index(
    json_t *jn_list,
    json_int_t value
);

Parameters

Key	Type	Description
`jn_list`	`json_t *`	The JSON array to search within.
`value`	`json_int_t`	The integer value to search for.

Returns

Returns the index of the integer value in the array if found, or -1 if not found.

`json_list_update()`¶

Extends a JSON array with values from another array, optionally treating it as a set.

int json_list_update(
    json_t *list,
    json_t *other,
    BOOL as_set_type
);

Parameters

Key	Type	Description
`list`	`json_t *`	The target JSON array to extend.
`other`	`json_t *`	The source JSON array whose values will be appended to `list`.
`as_set_type`	`BOOL`	If TRUE, only adds values from `other` that are not already present in `list`, treating the array as a set.

Returns

Returns 0 on success, or -1 on error.

`json_listsrange2set()`¶

Converts a mixed list of integers and integer ranges into a single flattened set of unique integers.

json_t *json_listsrange2set(
    json_t *listsrange
);

Parameters

Key	Type	Description
`listsrange`	`json_t *`	A JSON array containing integers and/or two-element integer range arrays. Not owned by the function.

Returns

Returns a new json_t * array containing the flattened set of unique integers, or NULL on error.

`json_range_list()`¶

Expands an integer range array into a full JSON array of all integers in that range.

json_t *json_range_list(
    json_t *list
);

Parameters

Key	Type	Description
`list`	`json_t *`	A two-element JSON array representing an integer range `[first, second]`.

Returns

Returns a new json_t * array containing all integers from first to second (inclusive), or NULL on error.

Notes

This function can be slow for large ranges, as it allocates an element for every integer in the range.

`json_replace_var()`¶

Replaces variable placeholders using default delimiters (^^ and ^^).

json_t *json_replace_var(
    json_t *jn_dict,
    json_t *jn_vars
);

Parameters

Key	Type	Description
`jn_dict`	`json_t *`	The JSON object containing string values with variable placeholders. Owned by the function.
`jn_vars`	`json_t *`	A JSON object mapping variable names to their replacement values. Owned by the function.

Returns

Returns a new json_t * with all placeholders replaced, or NULL on error.

`json_replace_var_custom()`¶

Replaces variable placeholders with custom delimiters.

json_t *json_replace_var_custom(
    json_t *jn_dict,
    json_t *jn_vars,
    const char *open,
    const char *close
);

Parameters

Key	Type	Description
`jn_dict`	`json_t *`	The JSON object containing string values with variable placeholders. Owned by the function.
`jn_vars`	`json_t *`	A JSON object mapping variable names to their replacement values. Owned by the function.
`open`	`const char *`	The opening delimiter string that marks the start of a variable placeholder.
`close`	`const char *`	The closing delimiter string that marks the end of a variable placeholder.

Returns

Returns a new json_t * with all placeholders replaced, or NULL on error.

`json_size()`¶

Returns the size of a JSON value based on its type.

size_t json_size(
    json_t *value
);

Parameters

Key	Type	Description
`value`	`json_t *`	The JSON value whose size is to be determined.

Returns

Returns the number of elements for arrays and objects, 1 for non-empty strings, and 0 for all other types (including empty strings, integers, reals, booleans, and null).

anystring2json()¶

bits2gbuffer()¶

bits2jn_strlist()¶

cmp_two_simple_json()¶

create_json_record()¶

debug_json()¶

get_real_precision()¶

jn2bool()¶

jn2integer()¶

jn2real()¶

jn2string()¶

json2str()¶

json2uglystr()¶

json_check_refcounts()¶

json_config()¶

json_desc_to_schema()¶

json_is_identical()¶

json_list_str_index()¶

json_print_refcounts()¶

json_str_in_list()¶

load_json_from_file()¶

load_persistent_json()¶

print_json()¶

save_json_to_file()¶

set_real_precision()¶

string2json()¶

strings2bits()¶

anyfile2json()¶

debug_json2()¶

is_metadata_key()¶

is_private_key()¶

json_config_string2json()¶

json_dict_recursive_update()¶

json_is_range()¶

json_list_find()¶

json_list_int()¶

json_list_int_index()¶

json_list_update()¶

json_listsrange2set()¶

json_range_list()¶

json_replace_var()¶

json_replace_var_custom()¶

json_size()¶

`anystring2json()`¶

`bits2gbuffer()`¶

`bits2jn_strlist()`¶

`cmp_two_simple_json()`¶

`create_json_record()`¶

`debug_json()`¶

`get_real_precision()`¶

`jn2bool()`¶

`jn2integer()`¶

`jn2real()`¶

`jn2string()`¶

`json2str()`¶

`json2uglystr()`¶

`json_check_refcounts()`¶

`json_config()`¶

`json_desc_to_schema()`¶

`json_is_identical()`¶

`json_list_str_index()`¶

`json_print_refcounts()`¶

`json_str_in_list()`¶

`load_json_from_file()`¶

`load_persistent_json()`¶

`print_json()`¶

`save_json_to_file()`¶

`set_real_precision()`¶

`string2json()`¶

`strings2bits()`¶

`anyfile2json()`¶

`debug_json2()`¶

`is_metadata_key()`¶

`is_private_key()`¶

`json_config_string2json()`¶

`json_dict_recursive_update()`¶

`json_is_range()`¶

`json_list_find()`¶

`json_list_int()`¶

`json_list_int_index()`¶

`json_list_update()`¶

`json_listsrange2set()`¶

`json_range_list()`¶

`json_replace_var()`¶

`json_replace_var_custom()`¶

`json_size()`¶