Add unix group database functions.

* configure (have_grgid): New variable.
New tests added for getgrent and the rest.
(HAVE_GRGID, HAVE_GRGID_R): New preprocessor symbols
conditionally deposited into config/config.h.

* sysif.c (group_s, mem_s): New global symbol variables.
(setgrent_wrap, endgrent_wrap, fill_group, make_grstruct,
get_grent_wrap, getgrgid_wrap, getgrnam_wrap): New static
functions.
(sysif_init): New global symbol variables initialized.
New group struct type instantiated.
Intrinsic functions setgrent, endgrent, getgrent,
getgrgid and getgrnam registered.

* txr.1: Documented group structure and functions.

1 files changed, 52 insertions, 0 deletions

diff --git a/configure b/configure
index 9a71902b..aa9c8f05 100755
--- a/configure
+++ b/configure
@@ -122,6 +122,7 @@ have_posix_sigs=
 need_darwin_c_source=
 have_git=
 have_pwuid=
+have_grgid=
 have_alloca=
 have_termios=
 have_winsize=
@@ -2108,6 +2109,57 @@ int main(void)
   fi
 fi
 
+printf "Checking for old school getgrent, getgrgid and getgrnam ... "
+
+cat > conftest.c <<!
+#include <sys/types.h>
+#include <grp.h>
+
+int main(void)
+{
+  struct group *g = getgrent();
+  struct group *h = getgrnam("root");
+  struct group *i = getgrgid(0);
+  setgrent();
+  endgrent();
+  return 0;
+}
+!
+
+if conftest ; then
+  printf "yes\n"
+  printf "#define HAVE_GRGID 1\n" >> $config_h
+  have_grgid=y
+else
+  printf "no\n"
+fi
+
+if [ "$have_grgid" ]; then
+  printf "Checking for getgrgid_r and getgrnam_r ... "
+
+  cat > conftest.c <<!
+#include <sys/types.h>
+#include <grp.h>
+
+int main(void)
+{
+  struct group gr;
+  struct group *g;
+  char buf[1024];
+  int r1 = getgrgid_r(0, &gr, buf, sizeof buf, &g);
+  int r2 = getgrnam_r("root", &gr, buf, sizeof buf, &g);
+  return 0;
+}
+!
+
+  if conftest ; then
+    printf "yes\n"
+    printf "#define HAVE_GRGID_R 1\n" >> $config_h
+  else
+    printf "no\n"
+  fi
+fi
+
 printf "Checking for alloca ... "
 
 for try_header in alloca.h malloc.h ; do