copyright: remove years from copyright headers

Also:
- uppercase `(C)`.
- add missing 'All rights reserved.' lines.
- drop duplicate 'Author' lines.
- add copyright headers where missing.
- enable copyright header check in checksrc.

Reasons for deleting years (copied as-is from curl):
- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- saves us from pointless churn
- git keeps history for us
- the year range is kept in COPYING

Closes #1082

example/CMakeLists.txt

@@ -1,5 +1,5 @@
-# Copyright (c) 2014, 2015 Alexander Lamaison <alexander.lamaison@gmail.com>
-# Copyright (c) 2023 Viktor Szakats
+# Copyright (C) Alexander Lamaison <alexander.lamaison@gmail.com>
+# Copyright (C) Viktor Szakats
 #
 # Redistribution and use in source and binary forms,
 # with or without modification, are permitted provided

example/direct_tcpip.c

@@ -1,3 +1,5 @@
+/* Copyright (C) The libssh2 project and its contributors. */
+
 #include "libssh2_setup.h"
 #include <libssh2.h>
 

example/scp.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do a simple SCP transfer.
  */
 

example/scp_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SCP transfers in a non-blocking manner.
  *
  * The sample code has default values for host name, user name, password

example/scp_write.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do an SCP upload.
  */
 

example/scp_write_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do an SCP non-blocking upload transfer.
  */
 

example/sftp.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP transfers.
  *
  * The sample code has default values for host name, user name, password

example/sftp_RW_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP transfers in a non-blocking manner.
  *
  * It will first download a given source file, store it locally and then

example/sftp_append.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP append of a local file onto a remote one.
  *
  * The sample code has default values for host name, user name, password

example/sftp_mkdir.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP mkdir
  *
  * The sample code has default values for host name, user name, password

example/sftp_mkdir_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP non-blocking mkdir.
  *
  * The sample code has default values for host name, user name, password

example/sftp_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP non-blocking transfers.
  *
  * The sample code has default values for host name, user name, password

example/sftp_write.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP write transfers.
  *
  * The sample code has default values for host name, user name, password

example/sftp_write_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP non-blocking write transfers.
  *
  * The sample code has default values for host name, user name, password

example/sftp_write_sliding.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SFTP non-blocking write transfers.
  *
  * The sample code has default values for host name, user name, password

example/sftpdir.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample doing an SFTP directory listing.
  *
  * The sample code has default values for host name, user name, password and

example/sftpdir_nonblock.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample doing an SFTP directory listing.
  *
  * The sample code has default values for host name, user name, password and

example/ssh2.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SSH2 connect.
  *
  * The sample code has default values for host name, user name, password

example/ssh2_agent.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to do SSH2 connect using ssh-agent.
  *
  * The sample code has default values for host name, user name:

example/ssh2_agent_forwarding.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to use libssh2 to request agent forwarding
  * on the remote host. The command executed will run with agent forwarded
  * so you should be able to do things like clone out protected git

example/ssh2_echo.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * The code sends a 'cat' command, and then writes a lot of data to it only to
  * check that reading the returned data sums up to the same amount.
  *

example/ssh2_exec.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to use libssh2 to execute a command remotely.
  *
  * The sample code has fixed values for host name, user name, password

example/subsystem_netconf.c

@@ -1,3 +1,5 @@
+/* Copyright (C) The libssh2 project and its contributors. */
+
 #include "libssh2_setup.h"
 #include <libssh2.h>
 

example/tcpip-forward.c

@@ -1,3 +1,5 @@
+/* Copyright (C) The libssh2 project and its contributors. */
+
 #include "libssh2_setup.h"
 #include <libssh2.h>
 

example/x11.c

@@ -1,4 +1,5 @@
-/*
+/* Copyright (C) The libssh2 project and its contributors.
+ *
  * Sample showing how to makes SSH2 with X11 Forwarding works.
  *
  * $ ./x11 host user password [DEBUG]