在Go语言中使用viper之类的库很方便的处理yaml配置文件，但是在C语言中就比较麻烦，经过一番思索和借助强大的github,发现了一个libyaml c库，但是网上的例子都比较麻烦，而且比较繁琐，就想法作了一个相对比较容易配置的解析应用，可以简单地类似viper 的模式进行配置实现不同的配置文件读取。如你的配置文件很复杂请按格式修改KeyValue 全局变量，欢迎大家一起完善
库请自行下载 GitHub - yaml/libyaml: Canonical source repository for LibYAML
直接上代码
yaml示例文件
%YAML 1.1
---
mqtt:
subtopic: "Control/#"
pubtopic: "bbt"
qos: 1
serveraddress: "tcp://192.168.0.25:1883"
clientid: "kvm_test"
writelog: false
writetodisk: false
outputfile: "./receivedMessages.txt"
hearttime: 30
#ifndef __CONFIG_H__
#define __CONFIG_H__
#ifdef __cplusplus
extern "C" {
#endif
/************************/
/* Minimum YAML version */
/************************/
#define YAML_VERSION_MAJOR 1
#define YAML_VERSION_MINOR 1
#define STRUCT_TYPE_NAME 100
#define INT_TYPE_NAME 101
#define STRING_TYPE_NAME 102
#define BOOL_TYPE_NAME 103
#define FLOAT_TYPE_NAME 104
#define MAP_TYPE_NAME 105
#define LIST_TYPE_NAME 106
typedef struct{
char *key;
void *value;
int valuetype;
char *parent;
}KeyValue,*pKeyValue;
#ifdef __cplusplus
}
#endif
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <errno.h>
#include <yaml.h>
#include "config.h"
typedef struct {
char *SUBTOPIC; //string `yaml:"subtopic" mapstructure:"subtopic"` //"topic1"
char *PUBTOPIC; //string `yaml:"pubtopic" mapstructure:"pubtopic"`
int QOS; //byte `yaml:"qos" mapstructure:"qos"` //1
char *SERVERADDRESS; //string `yaml:"serveraddress" mapstructure:"serveraddress"` //= "tcp://mosquitto:1883"
char *CLIENTID; //string `yaml:"clientid" mapstructure:"clientid"` //= "mqtt_subscriber"
int HEARTTIME; //int `yaml:"hearttime" mapstructure:"hearttime"`
// CommandLocalPath string `yam:"commanlocalpath"`
}mqttSection,*pmqttSection;
typedef struct {
mqttSection Mqtt;// `yaml:"mqtt" mapstructure:"mqtt"`
// KVM kvmSection `yaml:"kvm" mapstructure:"kvm"`
}ConfigT;
ConfigT config;
static KeyValue webrtcconfig[]={
{"mqtt",&config,STRUCT_TYPE_NAME,NULL},
{"subtopic",&(config.Mqtt.SUBTOPIC),STRING_TYPE_NAME,"mqtt"},
{"pubtopic",&(config.Mqtt.PUBTOPIC),STRING_TYPE_NAME,"mqtt"},
{"qos",&(config.Mqtt.QOS),INT_TYPE_NAME,"mqtt"},
{"serveraddress",&(config.Mqtt.SERVERADDRESS),STRING_TYPE_NAME,"mqtt"},
{"clientid",&(config.Mqtt.CLIENTID),STRING_TYPE_NAME,"mqtt"},
{"hearttime",&(config.Mqtt.HEARTTIME),INT_TYPE_NAME,"mqtt"},
{NULL,NULL,0,NULL},
};
int printConfig(ConfigT * pconfig){
if(pconfig==NULL) return -1;
printf("mqtt:rn");
if(pconfig->Mqtt.SUBTOPIC!=NULL) {printf("subtopic: %srn",pconfig->Mqtt.SUBTOPIC); }
if(pconfig->Mqtt.SUBTOPIC!=NULL) {printf("pubtopic: %srn",pconfig->Mqtt.PUBTOPIC); }
printf("qos: %drn",config.Mqtt.QOS);
if(pconfig->Mqtt.SERVERADDRESS!=NULL) {printf("serveraddress: %srn",pconfig->Mqtt.SERVERADDRESS); }
if(pconfig->Mqtt.CLIENTID!=NULL) {printf("clientid: %srn",pconfig->Mqtt.CLIENTID); }
printf("hearttime: %drn",config.Mqtt.HEARTTIME);
}
int freeConfig(ConfigT * pconfig){
if(pconfig==NULL) return -1;
if(pconfig->Mqtt.SERVERADDRESS!=NULL) {free(pconfig->Mqtt.SERVERADDRESS); }
if(pconfig->Mqtt.CLIENTID!=NULL) {free(pconfig->Mqtt.CLIENTID); }
if(pconfig->Mqtt.SUBTOPIC!=NULL) {free(pconfig->Mqtt.SUBTOPIC); }
}
char currentkey[100];
void getvalue(yaml_event_t event,pKeyValue *ppconfigs){
char *value = (char *)event.data.scalar.value;
pKeyValue pconfig=*ppconfigs;
char *pstringname;
while(pconfig->key!=NULL){
if(currentkey[0]!=0){
if(!strcmp(currentkey,pconfig->key))
{
switch(pconfig->valuetype){
case STRING_TYPE_NAME:
pstringname=strdup(value);
printf("get string value %srn",pstringname);
*((char**)pconfig->value)=pstringname;
memset(currentkey, 0, sizeof(currentkey));
break;
case INT_TYPE_NAME:
*((int*)(pconfig->value))=atoi(value);
memset(currentkey, 0, sizeof(currentkey));
break;
case BOOL_TYPE_NAME:
if(!strcmp(value,"true")) *((bool*)(pconfig->value))=true;
else *((bool*)(pconfig->value))=false;
memset(currentkey, 0, sizeof(currentkey));
break;
case FLOAT_TYPE_NAME:
*((float*)(pconfig->value))=atof(value);
memset(currentkey, 0, sizeof(currentkey));
break;
case STRUCT_TYPE_NAME:
case MAP_TYPE_NAME:
case LIST_TYPE_NAME:
memset(currentkey, 0, sizeof(currentkey));
strncpy(currentkey,value,strlen(value));
break;
default:
break;
}
break;
}
//continue;
}else{
if(!strcmp(value,pconfig->key)){
strncpy(currentkey,pconfig->key,strlen(pconfig->key));
break;
}
}
pconfig++;
}
}
int Load_YAML_Config( char *yaml_file, KeyValue *(configs[]) )
{
struct stat filecheck;
yaml_parser_t parser;
yaml_event_t event;
bool done = 0;
unsigned char type = 0;
unsigned char sub_type = 0;
if (stat(yaml_file, &filecheck) != false )
{
printf("[%s, line %d] Cannot open configuration file '%s'! %s", __FILE__, __LINE__, yaml_file, strerror(errno) );
return -1;
}
FILE *fh = fopen(yaml_file, "r");
if (!yaml_parser_initialize(&parser))
{
printf("[%s, line %d] Failed to initialize the libyaml parser. Abort!", __FILE__, __LINE__);
return -1;
}
if (fh == NULL)
{
printf("[%s, line %d] Failed to open the configuration file '%s' Abort!", __FILE__, __LINE__, yaml_file);
return -1;
}
memset(currentkey, 0, sizeof(currentkey));
/* Set input file */
yaml_parser_set_input_file(&parser, fh);
while(!done)
{
if (!yaml_parser_parse(&parser, &event))
{
/* Useful YAML vars: parser.context_mark.line+1, parser.context_mark.column+1, parser.problem, parser.problem_mark.line+1, parser.problem_mark.column+1 */
printf( "[%s, line %d] libyam parse error at line %ld in '%s'", __FILE__, __LINE__, parser.problem_mark.line+1, yaml_file);
}
if ( event.type == YAML_DOCUMENT_START_EVENT )
{
//yaml file first line is version
//%YAML 1.1
//---
yaml_version_directive_t *ver = event.data.document_start.version_directive;
if ( ver == NULL )
{
printf( "[%s, line %d] Invalid configuration file. Configuration must start with "%%YAML 1.1"", __FILE__, __LINE__);
}
int major = ver->major;
int minor = ver->minor;
if (! (major == YAML_VERSION_MAJOR && minor == YAML_VERSION_MINOR) )
{
printf( "[%s, line %d] Configuration has a invalid YAML version. Must be 1.1 or above", __FILE__, __LINE__);
return -1;
}
}
else if ( event.type == YAML_STREAM_END_EVENT )
{
done = true;
}
else if ( event.type == YAML_MAppING_END_EVENT )
{
sub_type = 0;
}
else if ( event.type == YAML_SCALAR_EVENT )
{
getvalue(event,configs);
}
}
return 0;
}
int main(int argc, char *argv[]){
pKeyValue pconfig=&webrtcconfig[0];
Load_YAML_Config("../../etc/kvmagent.yml",&pconfig);
printConfig(&config);
freeConfig(&config);
}
