Museum

     GETGRENT(S)               UNIX System V               GETGRENT(S)



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

     Syntax
          #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
          The getgrent, getgrgid, and getgrnam functions 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 */
          };

          The getgrent function 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.
          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(S), getpwent(S), group(F)

     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.

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

     Standards Conformance
          endgrent, fgetgrent, getgrent, and setgrent are conformant
          with:
          AT&T SVID Issue 2, Select Code 307-127;
          and The X/Open Portability Guide II of January 1987.

          getgrgid and getgrnam are conformant with:
          AT&T SVID Issue 2, Select Code 307-127;
          The X/Open Portability Guide II of January 1987;
          IEEE POSIX Std 1003.1-1988 with C Standard Language-
          Dependent System Support;
          and NIST FIPS 151-1.



                                             (printed 6/20/89)