Provide an option to run commands via sh -c

The new flag "shell" instructs pies to run the command marked with it
as '/bin/sh -c $command'. Alternative shell can be supplied ising the
'program' statement.

This is useful if the command line uses shell-specific features (command
or variable expansion, redirection, pipes, etc.)

This commit also fixes a bug in the 'env' statement handling: a single
argument with embedded whitespaces was undergoing word splitting and
thus incorrectly handled as multiple arguments.

* NEWS: Document changes.
* doc/pies.texi: Likewise.
* src/comp.c (component_free): Free command.
(component_finish): Split command into argv/argc as directed by the
CF_SHELL flag.
* src/pies.c (_cb_command): Remove. Functionality moved to
component_finish().
(_cb_env): Bugfix. Don't split arguments.
* src/pies.h (CF_SHELL): New flag.
(component) <command>: New member.

* tests/Makefile.am: Add new tests.
* tests/testsuite.at: Add new tests.
* tests/aux/respawn: Change default timeout to 1 second.
* tests/respawn.at: Minor change.
* tests/shell.at: New test.

3 files changed, 34 insertions, 43 deletions

diff --git a/src/comp.c b/src/comp.c
index 25f2657..499dfe5 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -173,2 +173,3 @@ component_free (struct component *comp)
   free (comp->program);
+  free (comp->command);
   if (comp->argv)
@@ -749,2 +750,25 @@ component_finish (struct component *comp, grecs_locus_t *locus)
 {
+  if (comp->flags & CF_SHELL)
+    {
+      comp->argc = 3;
+      comp->argv = grecs_calloc (comp->argc + 1, sizeof (comp->argv[0]));
+      comp->argv[0] = grecs_strdup (comp->program ? comp->program : "/bin/sh");
+      comp->argv[1] = grecs_strdup ("-c");
+      comp->argv[2] = grecs_strdup (comp->command);
+      comp->argv[3] = NULL;
+    }
+  else
+    {
+      struct wordsplit ws;
+      if (wordsplit (comp->command, &ws, WRDSF_DEFFLAGS))
+	{
+	  grecs_error (locus, 0, "wordsplit: %s",
+		       wordsplit_strerror (&ws));
+	  component_free (comp);
+	  return;
+	}
+      wordsplit_get_words (&ws, &comp->argc, &comp->argv);
+      wordsplit_free (&ws);
+    }
+
   if (comp->prereq)
diff --git a/src/pies.c b/src/pies.c
index 98488a6..6105ae6 100644
--- a/src/pies.c
+++ b/src/pies.c
@@ -526,33 +526,2 @@ config_array_to_argv (grecs_value_t *val, grecs_locus_t *locus, size_t *pargc)
 static int
-_cb_command (enum grecs_callback_command cmd,
-	      grecs_locus_t *locus,
-	      void *varptr, grecs_value_t *value, void *cb_data)
-{
-  struct component *comp = varptr;
-  struct wordsplit ws;
-
-  switch (value->type)
-    {
-    case GRECS_TYPE_STRING:
-      if (wordsplit (value->v.string, &ws, WRDSF_DEFFLAGS))
-	{
-	  grecs_error (locus, 0, "wordsplit: %s", strerror (errno));
-	  return 1;
-	}
-      wordsplit_get_words (&ws, &comp->argc, &comp->argv);
-      wordsplit_free (&ws);
-      break;
-
-    case GRECS_TYPE_ARRAY:
-      comp->argv = config_array_to_argv (value, locus, &comp->argc);
-      break;
-
-    case GRECS_TYPE_LIST:
-      grecs_error (locus, 0, _("unexpected list"));
-      return 1;
-    }
-  return 0;
-}
-
-static int
 _cb_umask (enum grecs_callback_command cmd,
@@ -591,9 +560,5 @@ _cb_env (enum grecs_callback_command cmd,
     case GRECS_TYPE_STRING:
-      if (wordsplit (value->v.string, &ws, WRDSF_DEFFLAGS))
-	{
-	  grecs_error (locus, 0, "wordsplit: %s", strerror (errno));
-	  return 1;
-	}
-      wordsplit_get_words (&ws, &argc, &argv);
-      wordsplit_free (&ws);
+      argv = grecs_calloc (2, sizeof (argv[0]));
+      argv[0] = grecs_strdup (value->v.string);
+      argv[1] = NULL;
       break;
@@ -889,2 +854,3 @@ str_to_cf (const char *string, int *flags)
     { "nullinput", CF_NULLINPUT },
+    { "shell", CF_SHELL },
     { NULL }
@@ -1016,5 +982,5 @@ struct grecs_keyword component_keywords[] = {
    grecs_type_string, GRECS_DFLT,
-   NULL, 0,
-   _cb_command,
-   },
+   NULL, offsetof (struct component, command),
+   NULL,
+  },
   {"prerequisites",
diff --git a/src/pies.h b/src/pies.h
index 74cb346..2e544e1 100644
--- a/src/pies.h
+++ b/src/pies.h
@@ -208,6 +208,6 @@ enum pies_comp_mode
 #define CF_SIGGROUP    0x100 /* Send signals to the process group */
-
 #define CF_NULLINPUT   0x200 /* Provide null input stream */
+#define CF_SHELL       0x400 /* Invoke via sh -c */
 
-#define CF_REMOVE      0x400 /* Marked for removal */
+#define CF_REMOVE      0xf000 /* Marked for removal */
 
@@ -228,2 +228,3 @@ struct component
   char *program;           /* Program name */
+  char *command;           /* Full command line */
   size_t argc;             /* Number of command line arguments */