第一：如何获取CPU的温度
应用可以定时获取CPU的温度，比如程序异常崩溃时，我们可能需要分析多方面原因，CPU温度就是其中之一。
#include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <errno.h> #define CPU_TEMP_FILE0 "/sys/devices/virtual/thermal/thermal_zone0/temp" struct cpu_temperature { int integer_part; int decimal_part; }; typedef struct cpu_temperature cpu_temperature_t; cpu_temperature_t get_cpu_temperature(const char *_cpu_temp_file) { FILE *fp = NULL; cpu_temperature_t cpu_temperature = {0}; int temp = 0; fp = fopen(_cpu_temp_file, "r"); if (NULL == fp) { printf("fopen file error\n"); return cpu_temperature; } fscanf(fp, "%d", &temp); cpu_temperature.integer_part = temp / 1000; cpu_temperature.decimal_part = temp % 1000 / 100; fclose(fp); return cpu_temperature; } int main(int arc, char *argv[]) { cpu_temperature_t cpu_temperature = {0}; cpu_temperature = get_cpu_temperature(CPU_TEMP_FILE0); printf("cpu_temperature = %d.%d ℃\n", cpu_temperature.integer_part, cpu_temperature.decimal_part); return 0; }
运行结果：
第二： 获取文件大小
有时间我们需要获取某个文件的大小，比如如果需要发送文件里的内容，则需要知道文件的大小。
#include <sys/stat.h> #include <unistd.h> #include <stdio.h> long get_file_size(const char *_file_name) { FILE * fp = fopen(_file_name, "r"); if (NULL == fp) { printf("fopen error\n"); return -1; } fseek(fp, 0L, SEEK_END); long size = ftell(fp); fclose(fp); return size; } int main() { #define FILE_NAME "./get_file_size" long file_size = get_file_size(FILE_NAME); printf("file_size = %ld\n", file_size); return 0; }
运行结果：
第三：获取时间戳
系统时间戳很常用，比如log输出时，可以附带时间戳数据，方便分析。
#include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <sys/time.h> #include <time.h> long long get_sys_time_ms(void) { long long time_ms = 0; struct timeval sys_current_time; gettimeofday(&sys_current_time, NULL); time_ms = ((long long)sys_current_time.tv_sec*1000000 + sys_current_time.tv_usec) / 1000; return time_ms; } int main(int arc, char *argv[]) { long long cur_sys_time = get_sys_time_ms(); printf("cur_sys_time = %lld ms\n", cur_sys_time); return 0; }
运行结果：
第四：获取MAC地址
MAC地址，有时候会作为设备ID实用，作业设备唯一标识。
#include <stdio.h> #include <net/if.h> #include <sys/ioctl.h> #include <arpa/inet.h> #include <unistd.h> #include <string.h> int get_netif_mac(const char *_ifr_name, uint8_t *_mac) { int32_t ret = -1; struct ifreq m_ifreq; int32_t sock = 0; sock = socket(AF_INET, SOCK_STREAM, 0); if (sock < 0) { printf("socket err\r\n"); goto err; } strcpy(m_ifreq.ifr_name, _ifr_name); ret = ioctl(sock,SIOCGIFHWADDR, &m_ifreq); if (ret < 0) { printf("ioctl err:%d\r\n",ret); goto err; } snprintf((char *)_mac, 32, "%02x%02x%02x%02x%02x%02x", (uint8_t)m_ifreq.ifr_hwaddr.sa_data[0], (uint8_t)m_ifreq.ifr_hwaddr.sa_data[1], (uint8_t)m_ifreq.ifr_hwaddr.sa_data[2], (uint8_t)m_ifreq.ifr_hwaddr.sa_data[3], (uint8_t)m_ifreq.ifr_hwaddr.sa_data[4], (uint8_t)m_ifreq.ifr_hwaddr.sa_data[5]); return 0; err: return -1; } int main(int argc, char **argv) { char mac_str[32] = {0}; get_netif_mac("wlan1", mac_str); printf("mac = %s\n", mac_str); return 0; }
运行结果：
第五：获取IP
有时候需要获取本机IP进行显示。
#include <stdio.h> #include <net/if.h> #include <sys/ioctl.h> #include <arpa/inet.h> #include <unistd.h> #include <string.h> int get_local_ip(const char *_ifr_name, char *_ip) { int ret = -1; int sockfd; struct sockaddr_in sin; struct ifreq ifr; sockfd = socket(AF_INET, SOCK_DGRAM, 0); if (-1 == sockfd) { printf("socket error\n"); return ret; } strncpy(ifr.ifr_name, _ifr_name, IFNAMSIZ); ifr.ifr_name[IFNAMSIZ - 1] = 0; if (ioctl(sockfd, SIOCGIFADDR, &ifr) < 0) { printf("ioctl error\n"); close(sockfd); return ret; } memcpy(&sin, &ifr.ifr_addr, sizeof(sin)); int ip_len = snprintf(_ip, 32, "%s", inet_ntoa(sin.sin_addr)); close(sockfd); ret = ip_len; return ret; } int main(int argc, char **argv) { char ip_str[32] = {0}; get_local_ip("wlan1", ip_str); printf("ip = %s\n", ip_str); return 0; }
运行结果：
