UNIX环境C语言编程(5)-系统数据文件

1、密码文件/etc/passwd

•#include <pwd.h>
•struct
passwd *getpwuid(uid_t
uid); //
根据uid读取
•struct
passwd *getpwnam(const char *name);//根据名称读取
•struct
passwd *getpwent(void); //
顺序读取
•void setpwent(void); //
回绕，从头再来
•void endpwent(void); //
结束
 

2、组文件/etc/group

•#include <grp.h>
•struct group *getgrgid(gid_t
gid); //
根据gid读取
•struct group *getgrnam(const
char *name);  // 根据名称读取
•struct group *getpwent(void); //
顺序读取
•void setgrent(void); //
回绕，从头再来
•void endgrent(void);   //
结束
 

3、其它数据文件



 

4、系统标识

•#include <sys/utsname.h>
•int uname(struct
utsname *name); //
获取系统信息
•struct
utsname
•{
•     char sysname[]; 
/* name of the operating system */
•     char nodename[]; 
/* name of this node */
•     char  release[];  /* current release of operating system */
•     char  version[];  /* current version of this release */
•     char  machine[];  /* name of hardware type */
•};
•#include <unistd.h>
•int gethostname(char *name,int
namelen); //
仅获取主机名称
 

5、时间/日期函数

•#include <time.h>
•#include <sys/time.h>
•time_t
time(time_t *calptr);
•int gettimeofday(struct
timeval *tp, void *tzp);
•struct tm *gmtime(const
time_t *calptr);
•struct tm *localtime(const
time_t *calptr);
•time_t
mktime(struct tm *tmptr);
•char *asctime(const
struct tm *tmptr);
•char *ctime(const
time_t *calptr);
•size_t
strftime(char *buf,size_t
maxsize,const char *format,const
struct tm *tmptr);