Standard C Library Functions getutxent(3C)
NAME
getutxent, getutxid, getutxline, pututxline, setutxent,
endutxent, utmpxname, getutmp, getutmpx, updwtmp, updwtmpx -
user accounting database functionsSYNOPSIS
#include
struct utmpx *getutxent(void); struct utmpx *getutxid(const struct utmpx *id); struct utmpx *getutxline(const struct utmpx *line); struct utmpx *pututxline(const struct utmpx *utmpx);void setutxent(void);
void endutxent(void); int utmpxname(const char *file); void getutmp(struct utmpx *utmpx, struct utmp *utmp); void getutmpx(struct utmp *utmp, struct utmpx *utmpx); void updwtmp(char *wfile, struct utmp *utmp); void updwtmpx(char *wfilex, struct utmpx *utmpx);DESCRIPTION
These functions provide access to the user accounting data-
base, utmpx (see utmpx(4)). Entries in the database are described by the definitions and data structures in. The utmpx structure contains the following members: char ut_user[32]; /* user login name */
char ut_id[4]; /* /etc/inittab id */
SunOS 5.11 Last change: 27 Jul 2004 1
Standard C Library Functions getutxent(3C)/* (usually line #) */
char ut_line[32]; /* device name */
/* (console, lnxx) */pid_t ut_pid; /* process id */
short ut_type; /* type of entry */
struct exit_status ut_exit; /* exit status of a process */
/* marked as DEAD_PROCESS */
struct timeval ut_tv; /* time entry was made */
int ut_session; /* session ID, used for */
/* windowing */short ut_syslen; /* significant length of */
/* ut_host */
/* including terminating null */char ut_host[257]; /* host name, if remote */
The exit_status structure includes the following members:
short e_termination; /* termination status */
short e_exit; /* exit status */
getutxent() The getutxent() function reads in the next entry from a utmpx database. If the database is not already open, it opens it. If it reaches the end of the database, it fails. getutxid() The getutxid() function searches forward from the current point in the utmpx database until it finds an entry with aut_type matching id->ut_type, if the type specified is
RUN_LVL, BOOT_TIME, DOWN_TIME, OLD_TIME, or NEW_TIME. If the
type specified in id is INIT_PROCESS, LOGIN_PROCESS,
USER_PROCESS, or DEAD_PROCESS, then getutxid() will return a
pointer to the first entry whose type is one of these fourand whose ut_id member matches id->ut_id. If the end of
database is reached without a match, it fails. getutxline() The getutxline() function searches forward from the current point in the utmpx database until it finds an entry of thetype LOGIN_PROCESS or USER_PROCESS which also has a ut_line
string matching the line->ut_line string. If the end of the
database is reached without a match, it fails. pututxline()The pututxline() function writes the supplied utmpx struc-
ture into the utmpx database. It uses getutxid() to search forward for the proper place if it finds that it is not already at the proper place. It is expected that normally the user of pututxline() will have searched for the properSunOS 5.11 Last change: 27 Jul 2004 2
Standard C Library Functions getutxent(3C)entry using one of the getutx() routines. If so, pututx-
line() will not search. If pututxline() does not find a matching slot for the new entry, it will add a new entry to the end of the database. It returns a pointer to the utmpxstructure. When called by a non-root user, pututxline()
invokes a setuid() root program to verify and write the entry, since the utmpx database is normally writable only byroot. In this event, the ut_name member must correspond to
the actual user name associated with the process; theut_type member must be either USER_PROCESS or DEAD_PROCESS;
and the ut_line member must be a device special file and be
writable by the user.setutxent()
The setutxent() function resets the input stream to the
beginning. This should be done before each search for a new entry if it is desired that the entire database be examined. endutxent() The endutxent() function closes the currently open database. utmpxname() The utmpxname() function allows the user to change the name of the database file examined from /var/adm/utmpx to any other file, most often /var/adm/wtmpx. If the file does not exist, this will not be apparent until the first attempt to reference the file is made. The utmpxname() function does not open the file, but closes the old file if it is currently open and saves the new file name. The new file name must end with the "x" character to allow the name ofthe corresponding utmp file to be easily obtainable.; other-
wise, an error value of 0 is returned. The function returns 1 on success. getutmp() The getutmp() function copies the information stored in the members of the utmpx structure to the corresponding members of the utmp structure. If the information in any member of utmpx does not fit in the corresponding utmp member, the data is silently truncated. (See getutent(3C) for utmp structure) getutmpx() The getutmpx() function copies the information stored in the members of the utmp structure to the corresponding membersof the utmpx structure. (See getutent(3C) for utmp struc-
ture) updwtmp() The updwtmp() function can be used in two ways.SunOS 5.11 Last change: 27 Jul 2004 3
Standard C Library Functions getutxent(3C) If wfile is /var/adm/wtmp, the utmp format record supplied by the caller is converted to a utmpx format record and the /var/adm/wtmpx file is updated (because the /var/adm/wtmp file no longer exists, operations on wtmp are converted to operations on wtmpx by the library functions. If wfile is a file other than /var/adm/wtmp, it is assumed to be an old file in utmp format and is updated directly with the utmp format record supplied by the caller. updwtmpx() The updwtmpx() function writes the contents of the utmpx structure pointed to by utmpx to the database. utmpx structureThe values of the e_termination and e_exit members of the
ut_exit structure are valid only for records of type
DEAD_PROCESS. For utmpx entries created by init(1M), these
values are set according to the result of the wait() call that init performs on the process when the process exits. See the wait(3C), manual page for the values init uses.Applications creating utmpx entries can set ut_exit values
using the following code example:u->ut_exit.e_termination = WTERMSIG(process->p_exit)
u->ut_exit.e_exit = WEXITSTATUS(process->p_exit)
See wait.h(3HEAD) for descriptions of the WTERMSIG and WEX-
ITSTATUS macros.The ut_session member is not acted upon by the operating
system. It is used by applications interested in creating utmpx entries.For records of type USER_PROCESS, the nonuser() and
nonuserx() macros use the value of the ut_exit.e_exit member
to mark utmpx entries as real logins (as opposed to multiple xterms started by the same user on a window system). This allows the system utilities that display users to obtain an accurate indication of the number of actual users, while still permitting each pty to have a utmpx record (as mostapplications expect.). The NONROOT_USER macro defines the
value that login places in the ut_exit.e_exit member.
RETURN VALUES
Upon successful completion, getutxent(), getutxid(), and getutxline() each return a pointer to a utmpx structureSunOS 5.11 Last change: 27 Jul 2004 4
Standard C Library Functions getutxent(3C) containing a copy of the requested entry in the user accounting database. Otherwise a null pointer is returned. The return value may point to a static area which isoverwritten by a subsequent call to getutxid () or getutx-
line(). Upon successful completion, pututxline() returns a pointer to a utmpx structure containing a copy of the entry added to the user accounting database. Otherwise a null pointer is returned.The endutxent() and setutxent() functions return no value.
A null pointer is returned upon failure to read, whether for permissions or having reached the end of file, or upon failure to write.USAGE
These functions use buffered standard I/O for input, but
pututxline() uses an unbuffered write to avoid race condi-
tions between processes trying to modify the utmpx and wtmpx files. Applications should not access the utmpx and wtmpx databases directly, but should use these functions to ensure that these databases are maintained consistently. FILES /var/adm/utmpx user access and accounting information /var/adm/wtmpx history of user access and accounting informationATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:SunOS 5.11 Last change: 27 Jul 2004 5
Standard C Library Functions getutxent(3C)____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | See below. ||_____________________________|_____________________________|
| MT-Level | Unsafe |
|_____________________________|_____________________________|
The endutxent(), getutxent(), getutxid(), getutxline(),pututxline(), and setutxent() functions are Standard.
SEE ALSO
getutent(3C), ttyslot(3C), wait(3C), wait.h(3HEAD), utmpx(4), attributes(5), standards(5) NOTESThe most current entry is saved in a static structure. Mul-
tiple accesses require that it be copied before further accesses are made. On each call to either getutxid() or getutxline(), the routine examines the static structurebefore performing more I/O. If the contents of the static structure match what it is searching for, it looks no further. For this reason, to use getutxline() to search for multiple occurrences it would be necessary to zero out the static after each success, or getutxline() would just return
the same structure over and over again. There is one excep-
tion to the rule about emptying the structure before further reads are done. The implicit read done by pututxline() (if it finds that it is not already at the correct place in the file) will not hurt the contents of the static structure returned by the getutxent(), getutxid(), or getutxline() routines, if the user has just modified those contents and passed the pointer back to pututxline().SunOS 5.11 Last change: 27 Jul 2004 6