Man

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LOGIN_TIMES(3)         FreeBSD Library Functions Manual         LOGIN_TIMES(3)

NAME
     parse_lt, in_lt, in_ltm, in_ltms, in_lts - functions for parsing and
     checking login time periods

LIBRARY
     System Utilities Library (libutil, -lutil)

SYNOPSIS
     #include <sys/types.h>
     #include <time.h>
     #include <login_cap.h>

     login_time_t
     parse_lt(const char *str);

     int
     in_lt(const login_time_t *lt, time_t *ends);

     int
     in_ltm(const login_time_t *lt, struct tm *t, time_t *ends);

     int
     in_ltms(const login_time_t *lt, struct tm *t, time_t *ends);

     int
     in_lts(const login_time_t *lt, time_t *ends);

DESCRIPTION
     This set of functions may be used for parsing and checking login and
     session times against a predefined list of allowed login times as used in
     login.conf(5).

     The format of allowed and disallowed session times specified in the
     times.allow and times.deny capability fields in a login class are
     comprised of a prefix which specifies one or more 2- or 3-character day
     codes, followed by a start and end time in 24 hour format separated by a
     hyphen.  Day codes may be concatenated together to select specific days,
     or the special mnemonics "Any" and "All" (for any/all days of the week),
     "Wk" for any day of the week (excluding Saturdays and Sundays) and "Wd"
     for any weekend day may be used.

     For example, the following time period:
           MoThFrSa1400-2200
     is interpreted as Monday, Thursday through Saturday between the hours of
     2pm and 10pm.
           Wd0600-1800
     means Saturday and Sunday, between the hours of 6am through 6pm, and
           Any0400-1600
     means any day of the week, between 4am and 4pm.

     Note that all time periods reference system local time.

     The parse_lt() function converts the ASCII representation of a time
     period into a structure of type login_time_t.  This is defined as:

     typedef struct login_time
     {
       u_short       lt_start;   /* Start time */
       u_short       lt_end;     /* End time */
       u_char        lt_dow;     /* Days of week */
     } login_time_t;

     The lt_start and lt_end fields contain the number of minutes past
     midnight at which the described period begins and ends.  The lt_dow field
     is a bit field, containing one bit for each day of the week and one bit
     unused.  A series LTM_* macros may be used for testing bits individually
     and in combination.  If no bits are set in this field - i.e., it contains
     the value LTM_NONE - then the entire period is assumed invalid.  This is
     used as a convention to mark the termination of an array of login_time_t
     values.  If parse_lt() returns a login_time_t with lt_dow equal to
     LTM_NONE then a parsing error was encountered.

     The remaining functions provide the ability to test a given time_t or
     struct tm value against a specific time period or array of time periods.
     The in_ltm() function determines whether the given time described by the
     struct tm passed as the second parameter falls within the period
     described by the first parameter.  A boolean value is returned,
     indicating whether or not the time specified falls within the period.  If
     the time does fall within the time period, and the third parameter to the
     function is not NULL, the time at which the period ends relative to the
     time passed is returned.

     The in_ltms() function is similar to in_ltm() except that the first
     parameter must be a pointer to an array of login_time_t objects, which is
     up to LC_MAXTIMES (64) elements in length, and terminated by an element
     with its lt_dow field set to LTM_NONE.

     The in_lt() and in_lts() functions are equivalent to in_ltm() and
     in_ltms(), respectively, with the second argument set to the current time
     as returned by localtime(3).

RETURN VALUES
     The parse_lt() function returns a filled in structure of type
     login_time_t containing the parsed time period.  If a parsing error
     occurs, the lt_dow field is set to LTM_NONE (i.e., 0).

     The in_ltm() function returns non-zero if the given time falls within the
     period described by the login_time_t passed as the first parameter.

     The in_ltms() function returns the index of the first time period found
     in which the given time falls, or -1 if none of them apply.

SEE ALSO
     getcap(3), login_cap(3), login_class(3), login.conf(5), termcap(5)

FreeBSD 11.1-RELEASE-p4        October 20, 2008        FreeBSD 11.1-RELEASE-p4
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