getgrent(3C)                                         getgrent(3C)



NAME
     getgrent, getgrgid, getgrnam, setgrent, endgrent, fgetgrent
     - get group file entry

SYNOPSIS
     #include <grp.h>

     struct group *getgrent ( )

     struct group *getgrgid (gid)
     gid_t gid;

     struct group *getgrnam (name)
     char *name;

     void setgrent ( )

     void endgrent ( )

SYNOPSIS (SYSV.2)
     struct group *fgetgrent (f)
     FILE *f;

DESCRIPTION
     getgrent, getgrgid and getgrnam each return pointers to an
     object with the following structure containing the broken-
     out fields of a line in the /etc/group file.  Each line con-
     tains a group structure, defined in the <grp.h> header file.
     This structure has the following members:

          char           *gr_name;  /* the name of the group */
          char           *gr_passwd;/* the encrypted group password */
          gid_t          gr_gid;    /* the numerical group ID */
          char           **gr_mem;  /* vector of pointers to member names */

     getgrent when first called returns a pointer to the first
     group structure in the file; thereafter, it returns a
     pointer to the next group structure in the file; so, succes-
     sive calls may be used to search the entire file.  Getgrgid
     searches from the beginning of the file until a numerical
     group id matching gid is found and returns a pointer to the
     particular structure in which it was found.  Getgrnam
     searches from the beginning of the file until a group name
     matching name is found and returns a pointer to the particu-
     lar structure in which it was found.  If an end-of-file or
     an error is encountered on reading, these functions return a
     NULL pointer.

     A call to setgrent has the effect of rewinding the group
     file to allow repeated searches.  Endgrent may be called to
     close the group file when processing is complete.




Page 1                        CX/UX Programmer's Reference Manual

getgrent(3C)                                         getgrent(3C)



     Fgetgrent returns a pointer to the next group structure in
     the stream f, which matches the format of /etc/group.

SECURITY FEATURES
     In CX/SX, the encrypted group passwords and names of group
     members are kept in /mls/group which is unreadable except by
     components of the Trusted Computing Base.  The file
     "/etc/group", which is the "shadow" or "sanitized" group
     file, is readable by all users but does not contain the
     encrypted password or the group members.

     If the effective-user-id of the process is "root" then get-
     grent, getgrgid and getgrname attempt to open the real
     (unsanitized) group file (/mls/passwd).  If this fails then
     they attempt to open the user visible "shadow" copy of the
     group file (/etc/group).

FILES
     /etc/group, /mls/group

SEE ALSO
     updatepwgr(1SX), getlogin(3C), getpwent(3C), group(4).

DIAGNOSTICS
     A NULL pointer is returned on EOF or error.

WARNING
     The above routines use <stdio.h>, which causes them to
     increase the size of programs, not otherwise using standard
     I/O, more than might be expected.

BUGS
     All information is contained in a static area, so it must be
     copied if it is to be saved.





















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