嵌入式 简单的读取文件并打印指定字符串的值

#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <fcntl.h>#include <sys/types.h>#ifdef __DEBUG__    #define msg_print(...) printf(__VA_ARGS__)#else    #define msg_print(...)#endif#define CONF_FILE_PATH "./ipnc_conf.conf"#define MAX_VALUE_LEN 32#define ARGV_NOT_EXIST 2#define ARGV_EXIST 5#define DEFALUT_JIPNC_ID "jipnc00000000005"#define DEFALUT_JIPNC_KEY "12345678"#define DEFALUT_JIPNC_DEVICE_TYPE "30"int joseph_read_conf(const char *key, char *value);int joseph_create_conf(const char *id, const char *key, const char *device_type, int flag);int joseph_create_conf(const char *id, const char *key, const char *device_type, int flag){   int conf_fd;   int ret;   char buffer[1024] = {0};      if(flag == ARGV_NOT_EXIST){   conf_fd = open(CONF_FILE_PATH, O_RDONLY | O_EXCL, 777);msg_print("conf_fd = %d\n",conf_fd);   if(conf_fd > 0){           close(conf_fd);           return 0;   }   }   conf_fd = open(CONF_FILE_PATH, O_WRONLY | O_CREAT | O_TRUNC, 777);   sprintf(buffer, "ipnc_id %s\nipnc_key %s\ndevice_type %s\n", id, key, device_type);   ret = write(conf_fd, buffer, 1024);   msg_print("ret = %d\nbuffer = %s", ret, buffer);   close(conf_fd);   return 0;}int joseph_read_conf(const char *key, char *value){    FILE *stream = NULL;    char cmd[64] = {0};    if(NULL == key || 0 == strlen(key)){    msg_print("invalid parameter!\n");return -1;    }    sprintf(cmd, "cat %s | awk '/%s/{print $2}'", CONF_FILE_PATH, key);    msg_print("cmd = %s\n",cmd);    stream = popen(cmd,"r");    if(fread(value, sizeof(char), MAX_VALUE_LEN, stream) <= 0){    pclose(stream);return -1;    }    strcpy(value + strlen(value) - 1, "\0");    msg_print("%s = %s\n", key, value);        pclose(stream);    system("rm -rf ./ipnc_conf.conf");    return 0;}int main(int argc,char *argv[]){    char value[32] = {0};    //if(argc != 1 || argc != 4)    //{    //printf("invalid parameter!\n");    //return -1;    //}#if 1    if(ARGV_NOT_EXIST == argc)    joseph_create_conf(DEFALUT_JIPNC_ID, DEFALUT_JIPNC_KEY ,DEFALUT_JIPNC_DEVICE_TYPE, ARGV_NOT_EXIST);    else if(ARGV_EXIST == argc)    joseph_create_conf(argv[1], argv[2] ,argv[3], ARGV_EXIST);    else{    printf("invalid parameter!\n");    return -1;    }#endif     joseph_read_conf("ipnc_id", value);    printf("%s = %s\n", "ipnc_id", value);    return 0;}