GETGRENT(3C)    (C Programming Language Utilities)   GETGRENT(3C)



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

  SYNOPSIS
       #include <grp.h>

       struct group *getgrent ( )

       struct group *getgrgid (gid)
       int gid;

       struct group *getgrnam (name)
       char *name;

       void setgrent ( )

       void endgrent ( )

       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
       contains a ``group'' structure, defined in the <grp.h>
       header file.

            struct group {
                   char    *gr_name;   /* the name of the group */
                   char    *gr_passwd; /* the encrypted group password */
                   int     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,
       successive calls may be used to search the entire file.


  Page 1                                                   May 1989

  GETGRENT(3C)    (C Programming Language Utilities)   GETGRENT(3C)



       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 particular 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.

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

  FILES
       /etc/group

  SEE ALSO
       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.

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









  Page 2                                                   May 1989