4.3 Global Control

In addition to selecting the appropriate theme, Clon provides two built-in options that give you additional control on the output. These options are orthogonal to themes: all themes implicitly honor them. Since their description is pretty self-explanatory, they are given below.

The first one allows you to control the output’s line width:

  --clon-line-width=WIDTH     Set Clon's output line width.
                              If not given, the value of the COLUMNS
                              environment variable, the terminal size,
                              or a default of 80 columns will be used.
                              Environment: CLON_LINE_WIDTH

The second one deals with highlighting (see Highlight). Clon has the ability to highlight the output through ISO/IEC 6429 SGR escape sequences. The built-in raw theme doesn’t do highlighting but other do.

  --clon-highlight[=ARG]      Set Clon's output highlighting to on/off/auto.
                              Auto (the default) means on for tty output and
                              off otherwise.
                              Fallback: yes
                              Default: auto
                              Environment: CLON_HIGHLIGHT

A word of caution is in order here. For technical reasons (in fact, the potential inability to detect a terminal properly), it is possible that the auto setting for --clon-highlight, which happens to be the default, doesn’t work. In such a case, highlight is switched off, and you need to use --clon-highlight=yes explicitely to force it.

For the same technical reason, it may be impossible to detect a terminal line width from time to time, in which case it would fall back to 80 columns. This particular problem is much less likely to bite you because the COLUMNS environment variable should be set all the time.

Both of these problems may or may not occur for specific applications, depending on their underlying implementation.