Introduce SPDX License Identifiers

This is a first step to make libcgi compliant to the REUSE initiative:

https://reuse.software/

We do this here before adding new files to the project, working towards
a consistent style in file headers.

Note: this is not complete, especially the following parts will take
additional attention:

* `test/trim.c` is in the public domain, SPDX has no identifier for that
  and it is not clear how to handle such situations.
* It is not clear where `src/md5.c` comes from, but it's deprecated
  anyway, so it will be removed in the future, circumventing any
  licensing problems with it. Also see #15 for that.
* There is no license applied to any code in the 'examples' folder, yet.

CMakeLists.txt

@@ -1,6 +1,9 @@
 #
 # Copyright 2013,2016–2018 Alexander Dahl <post@lespocky.de>
 #
+# SPDX-License-Identifier: LGPL-2.1+
+# License-Filename: LICENSES/LGPL-2.1.txt
+#
 
 cmake_minimum_required(VERSION 3.1)
 

LICENSES/MIT.txt

@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) 2001 Bob Trower, Trantor Standard Systems Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

include/libcgi/CMakeLists.txt

@@ -1,6 +1,9 @@
 #
 # Copyright 2018 Alexander Dahl <post@lespocky.de>
 #
+# SPDX-License-Identifier: LGPL-2.1+
+# License-Filename: LICENSES/LGPL-2.1.txt
+#
 
 configure_file(
 	"${CMAKE_CURRENT_SOURCE_DIR}/config.h.in"

include/libcgi/cgi.h

@@ -1,23 +1,12 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
 #ifndef _CGI_H
 #define _CGI_H	1
 

include/libcgi/error.h

@@ -1,3 +1,10 @@
+/*
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
+
 #ifndef _ERROR_H
 #define _ERROR_H	1
 

include/libcgi/session.h

@@ -1,23 +1,11 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 #ifndef _SESSION_H
 #define _SESSION_H	1

src/CMakeLists.txt

@@ -1,6 +1,9 @@
 #
 # Copyright 2013,2016,2018 Alexander Dahl <post@lespocky.de>
 #
+# SPDX-License-Identifier: LGPL-2.1+
+# License-Filename: LICENSES/LGPL-2.1.txt
+#
 
 set(CGI_SRC
 	base64.c

src/base64.c

@@ -1,32 +1,12 @@
 /*
-	LibCGI base64 manipulation functions is extremely based on the work of Bob Tower,
-	from its projec http://base64.sourceforge.net. The functions were a bit modicated.
-	Above is the MIT license from b64.c original code:
-
-LICENCE:        Copyright (c) 2001 Bob Trower, Trantor Standard Systems Inc.
-
-                Permission is hereby granted, free of charge, to any person
-                obtaining a copy of this software and associated
-                documentation files (the "Software"), to deal in the
-                Software without restriction, including without limitation
-                the rights to use, copy, modify, merge, publish, distribute,
-                sublicense, and/or sell copies of the Software, and to
-                permit persons to whom the Software is furnished to do so,
-                subject to the following conditions:
-
-                The above copyright notice and this permission notice shall
-                be included in all copies or substantial portions of the
-                Software.
-
-                THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
-                KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
-                WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-                PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
-                OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
-                OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-                OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
-                SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
-*/
+ * LibCGI base64 manipulation functions is extremely based on the work of Bob Tower,
+ * from its projec http://base64.sourceforge.net. The functions were a bit modicated.
+ *
+ * Copyright (c) 2001 Bob Trower, Trantor Standard Systems Inc.
+ *
+ * SPDX-License-Identifier: MIT
+ * License-Filename: LICENSES/MIT.txt
+ */
 
 #include <stdio.h>
 #include <stdlib.h>

src/cgi.c

@@ -1,23 +1,11 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 #include <stddef.h>
 #include <stdio.h>

src/cookie.c

@@ -1,23 +1,11 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 #include <stdio.h>
 #include <stdlib.h>

src/error.c

@@ -1,3 +1,12 @@
+/*
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
+
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>

src/general.c

@@ -1,23 +1,11 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 #include <stdio.h>
 #include <string.h>

src/list.c

@@ -1,24 +1,12 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-    Copyright 2016 Alexander Dahl <post@lespocky.de>
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ * Copyright 2016 Alexander Dahl <post@lespocky.de>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 #include <stdio.h>
 #include <stddef.h>

src/session.c

@@ -1,23 +1,11 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 /*****************************************************
  * The variables/functions beginning with sess_ are

src/string.c

@@ -1,23 +1,11 @@
 /*
-    LibCGI - A library to make CGI programs using C
-    Copyright (C) 2001/2002 Rafael Steil
-
-    This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Lesser General Public
-    License as published by the Free Software Foundation; either
-    version 2.1 of the License, or (at your option) any later version.
-
-    This library 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
-    Lesser General Public License for more details.
-
-    You should have received a copy of the GNU Lesser General Public
-    License along with this library; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-    You can contact the author by e-mail: rafael@insanecorp.com
-*/
+ * LibCGI - A library to make CGI programs using C
+ *
+ * Copyright 2001,2002 Rafael Steil <rafael@insanecorp.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ * License-Filename: LICENSES/LGPL-2.1.txt
+ */
 
 #include <stdio.h>
 #include <string.h>

test/CMakeLists.txt

@@ -1,6 +1,9 @@
 #
 # Copyright 2016–2018 Alexander Dahl <post@lespocky.de>
 #
+# SPDX-License-Identifier: LGPL-2.1+
+# License-Filename: LICENSES/LGPL-2.1.txt
+#
 
 # misc
 add_executable(cgi-test

test/cgi_test.c

@@ -1,11 +1,14 @@
 /*******************************************************************//**
- *	@file	cgi_test.c
+ *	@file		cgi_test.c
  *
  *	Actual test routines checking stuff we want to check in unit tests.
  *
- *	@author	Alexander Dahl <post@lespocky.de>
+ *	@author		Alexander Dahl <post@lespocky.de>
  *
- *	Copyright 2016 Alexander Dahl
+ *	SPDX-License-Identifier: LGPL-2.1+
+ *	License-Filename: LICENSES/LGPL-2.1.txt
+ *
+ *	@copyright	2016 Alexander Dahl <post@lespocky.de>
  **********************************************************************/
 
 #include "cgi_test.h"