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.

1 files changed, 24 insertions, 0 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)