[PATCH 1/2] consolidate grub_util_exec code

[Andrey Borzenkov <arvidjaar@gmail.com>]

We need to hide "modprobe efivars" error output to avoid confusion. So
consolidate grub_util_exec_* into single function that can optionally redirect
all three standard descriptors and make all other functions compatibility
wrappers.

Also remove include/grub/osdep/exec_unix.h which does not appear to be used
anywhere.
---
 grub-core/osdep/unix/exec.c    | 134 ++++++++++++++++++++---------------------
 include/grub/emu/exec.h        |   3 +
 include/grub/osdep/exec_unix.h |  39 ------------
 3 files changed, 68 insertions(+), 108 deletions(-)
 delete mode 100644 include/grub/osdep/exec_unix.h

diff --git a/grub-core/osdep/unix/exec.c b/grub-core/osdep/unix/exec.c
index d4865f6..935ff12 100644
--- a/grub-core/osdep/unix/exec.c
+++ b/grub-core/osdep/unix/exec.c
@@ -34,7 +34,8 @@
 #include <sys/wait.h>
 
 int
-grub_util_exec (const char *const *argv)
+grub_util_exec_redirect_all (const char *const *argv, const char *stdin_file,
+			     const char *stdout_file, const char *stderr_file)
 {
   pid_t pid;
   int status = -1;
@@ -43,71 +44,39 @@ grub_util_exec (const char *const *argv)
   grub_size_t strl = 0;
   for (ptr = argv; *ptr; ptr++)
     strl += grub_strlen (*ptr) + 1;
+  if (stdin_file)
+    strl += grub_strlen (stdin_file) + 2;
+  if (stdout_file)
+    strl += grub_strlen (stdout_file) + 2;
+  if (stderr_file)
+    strl += grub_strlen (stderr_file) + 3;
+
   pstr = str = xmalloc (strl);
   for (ptr = argv; *ptr; ptr++)
     {
       pstr = grub_stpcpy (pstr, *ptr);
       *pstr++ = ' ';
     }
-  if (pstr > str)
-    pstr--;
-  *pstr = '\0';
-
-  grub_util_info ("executing %s", str);
-  grub_free (str);
-
-  pid = fork ();
-  if (pid < 0)
-    grub_util_error (_("Unable to fork: %s"), strerror (errno));
-  else if (pid == 0)
+  if (stdin_file)
     {
-      /* Child.  */
-
-      /* Close fd's.  */
-#ifdef GRUB_UTIL
-      grub_util_devmapper_cleanup ();
-      grub_diskfilter_fini ();
-#endif
-
-      /* Ensure child is not localised.  */
-      setenv ("LC_ALL", "C", 1);
-
-      execvp ((char *) argv[0], (char **) argv);
-      exit (127);
+      *pstr++ = '<';
+      pstr = grub_stpcpy (pstr, stdin_file);
+      *pstr++ = ' ';
     }
-
-  waitpid (pid, &status, 0);
-  if (!WIFEXITED (status))
-    return -1;
-  return WEXITSTATUS (status);
-}
-
-int
-grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
-			 const char *stdout_file)
-{
-  pid_t pid;
-  int status = -1;
-  char *str, *pstr;
-  const char *const *ptr;
-  grub_size_t strl = 0;
-  for (ptr = argv; *ptr; ptr++)
-    strl += grub_strlen (*ptr) + 1;
-  strl += grub_strlen (stdin_file) + 2;
-  strl += grub_strlen (stdout_file) + 2;
-
-  pstr = str = xmalloc (strl);
-  for (ptr = argv; *ptr; ptr++)
+  if (stdout_file)
     {
-      pstr = grub_stpcpy (pstr, *ptr);
+      *pstr++ = '>';
+      pstr = grub_stpcpy (pstr, stdout_file);
       *pstr++ = ' ';
     }
-  *pstr++ = '<';
-  pstr = grub_stpcpy (pstr, stdin_file);
-  *pstr++ = ' ';
-  *pstr++ = '>';
-  pstr = grub_stpcpy (pstr, stdout_file);
-  *pstr = '\0';
+  if (stderr_file)
+    {
+      *pstr++ = '2';
+      *pstr++ = '>';
+      pstr = grub_stpcpy (pstr, stderr_file);
+      pstr++;
+    }
+  *--pstr = '\0';
 
   grub_util_info ("executing %s", str);
   grub_free (str);
@@ -117,7 +86,7 @@ grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
     grub_util_error (_("Unable to fork: %s"), strerror (errno));
   else if (pid == 0)
     {
-      int in, out;
+      int fd;
       /* Child.  */
       
       /* Close fd's.  */
@@ -126,18 +95,32 @@ grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
       grub_diskfilter_fini ();
 #endif
 
-      in = open (stdin_file, O_RDONLY);
-      if (in < 0)
-	exit (127);
-      dup2 (in, STDIN_FILENO);
-      close (in);
-
-      out = open (stdout_file, O_WRONLY | O_CREAT, 0700);
-      dup2 (out, STDOUT_FILENO);
-      close (out);
-
-      if (out < 0)
-	exit (127);
+      if (stdin_file)
+	{
+	  fd = open (stdin_file, O_RDONLY);
+	  if (fd < 0)
+	    exit (127);
+	  dup2 (fd, STDIN_FILENO);
+	  close (fd);
+	}
+
+      if (stdout_file)
+	{
+	  fd = open (stdout_file, O_WRONLY | O_CREAT, 0700);
+	  if (fd < 0)
+	    exit (127);
+	  dup2 (fd, STDOUT_FILENO);
+	  close (fd);
+	}
+
+      if (stderr_file)
+	{
+	  fd = open (stderr_file, O_WRONLY | O_CREAT, 0700);
+	  if (fd < 0)
+	    exit (127);
+	  dup2 (fd, STDERR_FILENO);
+	  close (fd);
+	}
 
       /* Ensure child is not localised.  */
       setenv ("LC_ALL", "C", 1);
@@ -152,9 +135,22 @@ grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
 }
 
 int
+grub_util_exec (const char *const *argv)
+{
+  return grub_util_exec_redirect_all (argv, NULL, NULL, NULL);
+}
+
+int
+grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
+			 const char *stdout_file)
+{
+  return grub_util_exec_redirect_all (argv, stdin_file, stdout_file, NULL);
+}
+
+int
 grub_util_exec_redirect_null (const char *const *argv)
 {
-  return grub_util_exec_redirect (argv, "/dev/null", "/dev/null");
+  return grub_util_exec_redirect_all (argv, "/dev/null", "/dev/null", NULL);
 }
 
 pid_t
diff --git a/include/grub/emu/exec.h b/include/grub/emu/exec.h
index ecc3adc..d1073ef 100644
--- a/include/grub/emu/exec.h
+++ b/include/grub/emu/exec.h
@@ -29,6 +29,9 @@ pid_t
 grub_util_exec_pipe_stderr (const char *const *argv, int *fd);
 
 int
+grub_util_exec_redirect_all (const char *const *argv, const char *stdin_file,
+			     const char *stdout_file, const char *stderr_file);
+int
 grub_util_exec (const char *const *argv);
 int
 grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
diff --git a/include/grub/osdep/exec_unix.h b/include/grub/osdep/exec_unix.h
deleted file mode 100644
index ecc3adc..0000000
--- a/include/grub/osdep/exec_unix.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 2013  Free Software Foundation, Inc.
- *
- *  GRUB is free software: you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation, either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  GRUB is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef GRUB_EMU_EXEC_H
-#define GRUB_EMU_EXEC_H 1
-
-#include <config.h>
-#include <stdarg.h>
-
-#include <sys/types.h>
-pid_t
-grub_util_exec_pipe (const char *const *argv, int *fd);
-pid_t
-grub_util_exec_pipe_stderr (const char *const *argv, int *fd);
-
-int
-grub_util_exec (const char *const *argv);
-int
-grub_util_exec_redirect (const char *const *argv, const char *stdin_file,
-			 const char *stdout_file);
-int
-grub_util_exec_redirect_null (const char *const *argv);
-
-#endif
-- 
1.8.4