@c ----------------------------------------------------------------------
@node getgrent, unix
@subheading Syntax

@example
#include <grp.h>

struct group *getgrent(void);
@end example

@subheading Description

This function returns the next available group entry.  Note that for
MS-DOS, this is simulated.  If the environment variable GROUP is set,
that is the name of the only group returned, else the only group is
"dos".  Thus, under DOS, @code{getgrent} will always fail on the
second and subsequent calls.

The return type of this and related function is as follows:

@example
struct group @{
  gid_t    gr_gid;    /* result of getgid() */
  char  ** gr_mem;    /* gr_mem[0] points to
                          getenv("USER"/"LOGNAME") or "user" */
  char  *  gr_name;   /* getenv("GROUP") or "dos" */
@};
@end example

@subheading Return Value

The next structure, or @code{NULL} at the end of the list.

@subheading Portability

@portability !ansi, !posix

@subheading Example

@example

struct group *g;
setgrent();
while ((g = getgrent()) != NULL)
@{
  printf("group %s gid %d\n", g->gr_name, g->gr_gid);
@}
endgrent();
@end example

@c ----------------------------------------------------------------------
@node fgetgrent, unix
@subheading Syntax

@example
#include <grp.h>

struct group *fgetgrent(FILE *file);
@end example

@subheading Description

This function, in MS-DOS, is exactly the same as @code{getgrent}
(@pxref{getgrent}). 

@subheading Portability

@portability !ansi, !posix

@c ----------------------------------------------------------------------
@node setgrent, unix
@subheading Syntax

@example
#include <grp.h>

void setgrent(void);
@end example

@subheading Description

This function should be called before any call to @code{getgrent},
@code{getgrgid}, or @code{getgrnam}, to start searching the groups' list
from the beginning.  @xref{getgrent}.

@subheading Return Value

None.

@subheading Portability

@portability !ansi, !posix

@c ----------------------------------------------------------------------
@node endgrent, unix
@subheading Syntax

@example
#include <grp.h>

void endgrent(void);
@end example

@subheading Description

This function should be called after all calls to @code{getgrent},
@code{getgrgid}, or @code{getgrnam}. 

@subheading Return Value

None.

@subheading Portability

@portability !ansi, !posix

@subheading Example

@xref{getgrent}.

@c ----------------------------------------------------------------------
@node getgrgid, unix
@subheading Syntax

@example
#include <grp.h>

extern struct group *getgrgid(int gid);
@end example

@subheading Description

This function returns the group entry that matches @var{gid}. 
@xref{getgrent}, for the description of @code{struct group}.

@subheading Return Value

The matching group, or @code{NULL} if none match.

@subheading Portability

@portability !ansi, posix

@c ----------------------------------------------------------------------
@node getgrnam, unix
@subheading Syntax

@example
#include <grp.h>

struct group *getgrnam(char *name);
@end example

@subheading Description

This function returns the group entry for the group named @var{name}. 
@xref{getgrent}, for the description of @code{struct group}.

@subheading Return Value

The matching group, or @code{NULL} if none match.


@subheading Portability

@portability !ansi, posix