Command-line Options

Each of the tools in our set has a command-line interface following the style of other common Unix tools and also allows command-line options to be specified in a file (Section ), whose name is given on the command line. As for most Unix tools, almost all command options have both long and short forms. The short forms start with a single ``-'', the long ones with two. Some options take additional parameters. With the short form, these parameters can be put directly after the command option (``-nnewname'') or can be separated from it by a blank (``-n newname''). With the long form, there may be a ``='' (``--name=newname'') or a blank (``--name newname'') separating the parameter from the command option. The long forms may be abbreviated (``--na=newname'') as long as the prefix is unique among the switches available for the tool in question.

If some parameters contain special characters, such as ``*'', ``('' or ``"'', this can lead to conflicts with the shell, which tries to interpret these characters in its own way. The interpretation of a character can be prevented in most shells, by either putting a ``\'' before the character or by quoting the word (or parts containing the special characters) with ``'''. For example:

   sus2sus '--filter=int(points)>100' --add quad=simp\*simp

Notice that when an option is enclosed in quotes, the ``='' separator between the option name and the value is necessary.

Another way of getting around the problem of these special characters is the use of command input files (Section  ). Every character is such a file is treated literally, which means that special characters need not (indeed must not) be quoted. You can insert the parameters of a command inpu file at any point in the command line using ``@ <filename>'' or ``@<filename>''. All styles of input on the command line can be mixed:

  labrun --cvs=~/dir --name test -ccomment1 -c comment2 @optfile

All lab-programs start other programs. This gives rise to the additional problem that when passing the commands via a shell command, the special characters have to be quoted again. For this reason the characters ``[]<>()$ *?\"'\|;&'' are quoted by a backslash once read in by the tools. If you want the characters to be interpreted by a shell, you have to include a ``sh -c'' command explicitly. (See page  for an example.)