Add --shell, --shell-arg settings

1 files changed, 25 insertions, 3 deletions

diff --git a/yarn b/yarn
index 3ca0bd5..a18aa8e 100755
--- a/yarn
+++ b/yarn
@@ -88,6 +88,18 @@ class YarnRunner(cliapp.Application):
             ['require-assumptions'],
             'require ASSUMING to always pass')
 
+        self.settings.string(
+            ['shell'],
+            'run IMPLEMENTS using SHELL',
+            metavar='SHELL',
+            default='/bin/sh')
+
+        self.settings.string_list(
+            ['shell-arg'],
+            'use ARG when running shell',
+            metavar='ARG',
+            default=['-xeu'])
+
     def stdout(self, msg):
         self.output.write(msg)
         self.output.flush()
@@ -436,10 +448,20 @@ class YarnRunner(cliapp.Application):
         for i, match in enumerate(m.groups('')):
             env['MATCH_%d' % (i+1)] = match
 
-        shell_script = '%s\n\n%s\n' % (
-            shell_prelude, step.implementation.shell)
+        fd, shell_script = tempfile.mkstemp()
+        os.close(fd)
+        with open(shell_script, 'w') as f:
+            f.write(shell_prelude)
+            f.write(step.implementation.shell)
+            f.flush()
+        shell = self.settings['shell']
+        shell_args = self.settings['shell-arg']
+        logging.warning('shell: %r', shell)
+        logging.warning('shell_args: %r', shell_args)
+        logging.warning('shell_script: %r', shell_script)
         exit, stdout, stderr = cliapp.runcmd_unchecked(
-            ['sh', '-xeuc', shell_script], env=env)
+            [shell] + shell_args + [shell_script], env=env)
+        os.remove(shell_script)
 
         logging.debug('Exit code: %d' % exit)
         if stdout: