diff --git a/ext/misc/rot13.c b/ext/misc/rot13.c new file mode 100644 index 0000000000..68fdf60b0f --- /dev/null +++ b/ext/misc/rot13.c @@ -0,0 +1,114 @@ +/* +** 2013-05-15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +****************************************************************************** +** +** This SQLite extension implements a rot13() function and a rot13 +** collating sequence. +*/ +#include "sqlite3ext.h" +SQLITE_EXTENSION_INIT1 +#include +#include + +/* +** Perform rot13 encoding on a single ASCII character. +*/ +static unsigned char rot13(unsigned char c){ + if( c>='a' && c<='z' ){ + c += 13; + if( c>'z' ) c -= 26; + }else if( c>='A' && c<='Z' ){ + c += 13; + if( c>'Z' ) c -= 26; + } + return c; +} + +/* +** Implementation of the rot13() function. +** +** Rotate ASCII alphabetic characters by 13 character positions. +** Non-ASCII characters are unchanged. rot13(rot13(X)) should always +** equal X. +*/ +static void rot13func( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + const unsigned char *zIn; + int nIn; + unsigned char *zOut; + char *zToFree = 0; + int i; + char zTemp[100]; + assert( argc==1 ); + if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return; + zIn = (const unsigned char*)sqlite3_value_text(argv[0]); + nIn = sqlite3_value_bytes(argv[0]); + if( nIn