getgrent(3C)                                         getgrent(3C)



     NAME
          getgrent, getgrgid, getgrnam, setgrent, endgrent, fgetgrent
          - obtain group file entry from a group file

     SYNOPSIS
          #include <grp.h>

          struct group *getgrent()

          struct group *getgrgid(gid)
          gid_t gid;

          struct group *getgrnam(name)
          char *name;

          void setgrent()

          struct group *fgetgrent(f)
          FILE *f;

          void endgrent()

     DESCRIPTION
          getgrent, getgrgid, and getgrnam return pointers to an ob-
          ject 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 numeric group ID */
                  char   **gr_mem;   /* vector of pointers to
                                        member names */
          };

          When first called, getgrent returns a pointer to the first
          group structure in the file.  Thereafter, it returns a
          pointer to the next group structure in the file; therefore,
          successive calls may be used to search the entire file.
          getgrgid searches from the beginning of the file until a
          numeric group ID matching gid is found; it returns a pointer
          to the particular structure in which the match was found.
          getgrnam searches from the beginning of the file until a
          group name matching name is found; it returns a pointer to
          the particular structure in which the match 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



     April, 1990                                                     1

     getgrent(3C)                                         getgrent(3C)



          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.

     RETURN VALUE
          If an end-of-file or an error is encountered, a NULL pointer
          is returned.

     FILES
          /etc/group

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

     WARNINGS
          The routines use <stdio.h>.  Therefore, the size of programs
          not otherwise using standard I/O is increased 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.
































     2                                                     April, 1990