File I/O statements and APIs

Enhancement reference: BZ#19156

IBM^® Informix^® 4GL version 7.50.xC4 introduced file manipulation instructions to access files on the operating system running the application. These instructions can be used to open, read, write, seek and close files:

MAIN
   DEFINE fd1, fd2 INTEGER, v1,v2 VARCHAR(10)
   OPEN FILE fd1 FROM "/tmp/file1" OPTIONS (READ, FORMAT="CVS")
   OPEN FILE fd2 FROM "/tmp/file2" OPTIONS (WRITE, APPEND, CREATE, FORMAT="CVS")
   READ FROM fd1INTO v1, v2
   SEEK ON fd2TO 0FROM LAST INTO v1
   WRITE TO fd2USING v1, v2
   CLOSE FILE fd1
   CLOSE FILE fd2
END MAIN

Genero Business Development Language (BDL) implements file I/O support with the base.Channel built-in class. This class implements file access, but it can also open streams to subprocesses (i.e. pipes) and sockets.