1 #pragma once 2 3 // This module implements a configuration parser. Clients can query the 4 // contents of a configuration file through the interface provided here. 5 // The current implementation is read-only; mutations are only kept in 6 // memory. This parser supports the INI file format. 7 8 // Implementation notes: 9 // - Key/value pairs that are not within a section are assumed to be under 10 // the |CONFIG_DEFAULT_SECTION| section. 11 // - Multiple sections with the same name will be merged as if they were in 12 // a single section. 13 // - Empty sections with no key/value pairs will be treated as if they do 14 // not exist. In other words, |config_has_section| will return false for 15 // empty sections. 16 // - Duplicate keys in a section will overwrite previous values. 17 // - All strings are case sensitive. 18 19 #include <stdbool.h> 20 21 // The default section name to use if a key/value pair is not defined within 22 // a section. 23 #define CONFIG_DEFAULT_SECTION "Global" 24 25 typedef struct config_t config_t; 26 typedef struct config_section_node_t config_section_node_t; 27 28 // Creates a new config object with no entries (i.e. not backed by a file). 29 // This function returns a config object or NULL on error. Clients must call 30 // |config_free| on the returned handle when it is no longer required. 31 config_t *config_new_empty(void); 32 33 // Loads the specified file and returns a handle to the config file. If there 34 // was a problem loading the file or allocating memory, this function returns 35 // NULL. Clients must call |config_free| on the returned handle when it is no 36 // longer required. |filename| must not be NULL and must point to a readable 37 // file on the filesystem. 38 config_t *config_new(const char *filename); 39 40 // Frees resources associated with the config file. No further operations may 41 // be performed on the |config| object after calling this function. |config| 42 // may be NULL. 43 void config_free(config_t *config); 44 45 // Returns true if the config file contains a section named |section|. If 46 // the section has no key/value pairs in it, this function will return false. 47 // |config| and |section| must not be NULL. 48 bool config_has_section(const config_t *config, const char *section); 49 50 // Returns true if the config file has a key named |key| under |section|. 51 // Returns false otherwise. |config|, |section|, and |key| must not be NULL. 52 bool config_has_key(const config_t *config, const char *section, const char *key); 53 54 // Returns the integral value for a given |key| in |section|. If |section| 55 // or |key| do not exist, or the value cannot be fully converted to an integer, 56 // this function returns |def_value|. |config|, |section|, and |key| must not 57 // be NULL. 58 int config_get_int(const config_t *config, const char *section, const char *key, int def_value); 59 60 // Returns the boolean value for a given |key| in |section|. If |section| 61 // or |key| do not exist, or the value cannot be converted to a boolean, this 62 // function returns |def_value|. |config|, |section|, and |key| must not be NULL. 63 bool config_get_bool(const config_t *config, const char *section, const char *key, bool def_value); 64 65 // Returns the string value for a given |key| in |section|. If |section| or 66 // |key| do not exist, this function returns |def_value|. The returned string 67 // is owned by the config module and must not be freed. |config|, |section|, 68 // and |key| must not be NULL. |def_value| may be NULL. 69 const char *config_get_string(const config_t *config, const char *section, const char *key, const char *def_value); 70 71 // Sets an integral value for the |key| in |section|. If |key| or |section| do 72 // not already exist, this function creates them. |config|, |section|, and |key| 73 // must not be NULL. 74 void config_set_int(config_t *config, const char *section, const char *key, int value); 75 76 // Sets a boolean value for the |key| in |section|. If |key| or |section| do 77 // not already exist, this function creates them. |config|, |section|, and |key| 78 // must not be NULL. 79 void config_set_bool(config_t *config, const char *section, const char *key, bool value); 80 81 // Sets a string value for the |key| in |section|. If |key| or |section| do 82 // not already exist, this function creates them. |config|, |section|, |key|, and 83 // |value| must not be NULL. 84 void config_set_string(config_t *config, const char *section, const char *key, const char *value); 85 86 // Removes |section| from the |config| (and, as a result, all keys in the section). 87 // Returns true if |section| was found and removed from |config|, false otherwise. 88 // Neither |config| nor |section| may be NULL. 89 bool config_remove_section(config_t *config, const char *section); 90 91 // Removes one specific |key| residing in |section| of the |config|. Returns true 92 // if the section and key were found and the key was removed, false otherwise. 93 // None of |config|, |section|, or |key| may be NULL. 94 bool config_remove_key(config_t *config, const char *section, const char *key); 95 96 // Returns an iterator to the first section in the config file. If there are no 97 // sections, the iterator will equal the return value of |config_section_end|. 98 // The returned pointer must be treated as an opaque handle and must not be freed. 99 // The iterator is invalidated on any config mutating operation. |config| may not 100 // be NULL. 101 const config_section_node_t *config_section_begin(const config_t *config); 102 103 // Returns an iterator to one past the last section in the config file. It does not 104 // represent a valid section, but can be used to determine if all sections have been 105 // iterated over. The returned pointer must be treated as an opaque handle and must 106 // not be freed and must not be iterated on (must not call |config_section_next| on 107 // it). |config| may not be NULL. 108 const config_section_node_t *config_section_end(const config_t *config); 109 110 // Moves |iter| to the next section. If there are no more sections, |iter| will 111 // equal the value of |config_section_end|. |iter| may not be NULL and must be 112 // a pointer returned by either |config_section_begin| or |config_section_next|. 113 const config_section_node_t *config_section_next(const config_section_node_t *iter); 114 115 // Returns the name of the section referred to by |iter|. The returned pointer is 116 // owned by the config module and must not be freed by the caller. The pointer will 117 // remain valid until |config_free| is called. |iter| may not be NULL and must not 118 // equal the value returned by |config_section_end|. 119 const char *config_section_name(const config_section_node_t *iter); 120 121 // Saves |config| to a file given by |filename|. Note that this could be a destructive 122 // operation: if |filename| already exists, it will be overwritten. The config 123 // module does not preserve comments or formatting so if a config file was opened 124 // with |config_new| and subsequently overwritten with |config_save|, all comments 125 // and special formatting in the original file will be lost. Neither |config| nor 126 // |filename| may be NULL. 127 bool config_save(const config_t *config, const char *filename); 128
