Implement -E option and <safearg.h> header.

The -E option is not passed through to the Awk implementation
any more, which is not particularly useful, because the option
resembles -f, and its argument requires likewise handling.

We achieve the semantics that -E <name> is equivalent to
-f <name> --.

From the GNU Awk user's perspective, this is a regression
in the semantics of -E which also has the effect of suppressing
the processing of arguments which look like variable assignments.
To make up for that, we provide the <safearg.h> header which
suppresses all implicit treatment of the remaining arguments.

1 files changed, 48 insertions, 0 deletions

diff --git a/share/cppawk/include/safearg.h b/share/cppawk/include/safearg.h
new file mode 100644
index 0000000..5016155
--- /dev/null
+++ b/share/cppawk/include/safearg.h
@@ -0,0 +1,48 @@
+// cppawk: C preprocessor wrapper around awk
+// Copyright 2022 Kaz Kylheku <kaz@kylheku.com>
+//
+// BSD-2 License
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice,
+//    this list of conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef __CPPAWK_SAFEARG_H
+#define __CPPAWK_SAFEARG_H
+
+#ifndef __CPPAWK_BASE_H
+#include "base.h"
+#endif
+
+BEGIN {
+  for (__key in ARGV) {
+    argv[__key] = ARGV[__key]
+#if !__gawk__
+    delete ARGV[__key]
+#endif
+  }
+
+#if __gawk__
+  delete ARGV
+#endif
+}
+
+#endif