嵌入式Memo37 linux 自己实现ls -l ll time localtime小程序 On Aug 21 2013

linux ls -l：程序实现

#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <time.h>
#include <string.h>

#define do_error(error) \//宏 打印错误信息
    do{\
        perror("error");\
        exit(-1);\
    }while(0)\

int main (int argc, char *argv[])
{
    DIR *dirp;
    struct dirent *direntp;
    struct stat info;
    struct passwd *passwd_p;
    struct group *group_p;
    struct tm *tm_p;
    char fullpath[128] = {0};
//    char str[11] = "----------";//-rwx------
    if((dirp = opendir(argv[1])) == NULL)//打开由程序给的路径参数./a.out ./(将程序编译成a.out，等价于ls -l ./)
        do_error(opendir);
    while((direntp = readdir(dirp)) != NULL)//读取第一个文件，默认文件加1，读取之后指针指向下一个文件，循环遍历全部文件
    {
        if(direntp->d_name[0] != '.')//屏蔽隐藏文件.或..
        {
            sprintf(fullpath,"%s/%s",argv[1],direntp->d_name);//由于readdir操作的是当前路径，
                                                              //当查看其它路径文件属性时使用直接direntp->d_name会出错，这里将路径和文件名粘贴起来
                                                              //也可以使用strcat函数拼接。
            if(stat(fullpath,&info) == -1)
                perror("stat");
            char str[11] = "----------";
/*            if(S_ISREG(info.st_mode)) str[0] = '-';
            if(S_ISDIR(info.st_mode)) str[0] = 'd';
            if(S_ISCHR(info.st_mode)) str[0] = 'c';
            if(S_ISBLK(info.st_mode)) str[0] = 'b';
            if(S_ISFIFO(info.st_mode)) str[0] = 'f';
            if(S_ISLNK(info.st_mode)) str[0] = 'l';
            if(S_ISSOCK(info.st_mode)) str[0] = 's';*/

            switch(info.st_mode & S_IFMT)               //查看属性
            {
                case S_IFREG: str[0] = '-'; break;
                case S_IFDIR: str[0] = 'd'; break;
                case S_IFCHR: str[0] = 'c'; break;
                case S_IFBLK: str[0] = 'b'; break;
                case S_IFIFO: str[0] = 'f'; break;
                case S_IFLNK: str[0] = 'l'; break;
                case S_IFSOCK: str[0] = 's'; break;
            }

            if(info.st_mode & S_IRUSR) str[1] = 'r';
            if(info.st_mode & S_IWUSR) str[2] = 'w';
            if(info.st_mode & S_IXUSR) str[3] = 'x';

            if(info.st_mode & S_IRGRP) str[4] = 'r';
            if(info.st_mode & S_IWGRP) str[5] = 'w';
            if(info.st_mode & S_IXGRP) str[6] = 'x';

            if(info.st_mode & S_IROTH) str[7] = 'r';
            if(info.st_mode & S_IWOTH) str[8] = 'w';
            if(info.st_mode & S_IXOTH) str[9] = 'x';

            passwd_p = getpwuid(info.st_uid);
            group_p = getgrgid(info.st_gid);

            tm_p = localtime(&info.st_mtime);    //获取时间属性，文章末尾附上时间函数的使用

            printf("%s %d %s %s %6ld %d-%02d-%02d %02d:%02d:%02d %s\n",str,info.st_nlink,passwd_p->pw_name, group_p->gr_name, info.st_size, tm_p->tm_year+1900, tm_p->tm_mon+1, tm_p->tm_mday, tm_p->tm_hour, tm_p->tm_min, tm_p->tm_sec, direntp->d_name);
        }
    }

    closedir(dirp);
    return 0;
}

************************************************
二：time localtime
    每隔一秒向文件传入一个时间，程序再次运行，时间接上次序号，如：
  1,2007-30 15:16:42
  2,2007-30 15:16:43
  3,2007-30 15:16:44
  4,2007-30 15:20:12
  5,2007-30 15:20:13
    

#include <stdio.h>
#include <unistd.h>
#include <time.h>

int main (int argc, char *argv[])
{
    int count = 1;
    time_t t;
    struct tm *tm;
    char buff[100];
    FILE *fp;
    if((fp = fopen(argv[1],"a+")) == NULL)
        perror("fopen");
    while(fgets(buff, 100, fp) != NULL)
    {
        int len=strlen(buff);//这里可以直接写为count++；有一点小bug
        if(buff[len-1]=='\n')
            count++;
    }
    while(1)
    {
        t = time(NULL);//t=time((time_t *)NULL);t是秒数计数开始点为1900.0100
        tm = localtime(&t);//
        fprintf(fp, "%d,%d-%d-%d %d:%d:%d\n", count++, tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
        fflush(fp);
        sleep(1);
    }
    return 0;
}