Differences from the IRAF CL

• GOTOs in CL scripts are only supported in the forward direction. Backward-moving GOTOs are not supported (no plans)
• There is no package unloading: 'bye' has no effect. (no plans, though we are considering alternative, more Pythonic approaches to similar functionality)
• There is no background execution. The cache command, which is used to keep parameter lists in memory for script execution (and apparently is useful only for background execution), also is not implemented. (may be considered)
• The rarely-used fprint built-in task is not implemented (not to be confused with printf, which is available.) The hidden tasks _allocate, _deallocate, and _devstatus are not supported. (no plans)
• The stty playback mode is not implemented. Playback mode is used for some CL demo scripts; it is typically highly specific to xgterm and the IRAF CL (including, for example, the keystrokes used inside the IRAF version of epar.) Other features associated with playback mode (login, logio, logout, verify, delay) are also unimplemented, as are some other stty features (e.g., ucasein & ucaseout). (no plans)
• The CL keeplog parameter is ignored. (Use the PyRAF .logfile directive to keep a log of your session.) The putlog command is also ignored. (no plans)
• PyRAF does not limit the length of CL struct strings. PyRAF strings can be arbitrarily long. (no plans)
• Automatic conversion of characters to integers in assignments is not supported. In the CL, i="Z" is a legal statement and results in i being assigned the ASCII integer equivalent to the character "Z". (no plans)
• An unusual (little known) CL behavior involving adding integers to strings that end in numbers is not supported. In the CL, 'test5'+5 is 'test10'. In PyRAF, 'test5'+5 = 'test55'. (no plans)
• Task definitions that reference files using IRAF networking (host!filename) are not supported. (no plans)
• Binary I/O to tasks is not supported. An example is in bench$bench.cl:

  task $wipc.bb = "bench$x_bench.c"
  

  The wipc task expects to read binary data from stdin and writes binary data to stdout. This capability does not appear to be used elsewhere in the IRAF system. (may be considered, though low priority because this is little used)