Info Catalog groff: Writing Macros groff: Writing Macros groff: Parameters

groff: Copy-in Mode

 
 5.21.1 Copy-in Mode
 -------------------
 
 When 'gtroff' reads in the text for a macro, string, or diversion, it
 copies the text (including request lines, but excluding escapes) into an
 internal buffer.  Escapes are converted into an internal form, except
 for '\n', '\$', '\*', '\\' and '\<RET>', which are evaluated and
 inserted into the text where the escape was located.  This is known as
 "copy-in" mode or "copy" mode.
 
    What this means is that you can specify when these escapes are to be
 evaluated (either at copy-in time or at the time of use) by insulating
 the escapes with an extra backslash.  Compare this to the '\def' and
 '\edef' commands in TeX.
 
    The following example prints the numbers 20 and 10:
 
      .nr x 20
      .de y
      .nr x 10
      \&\nx
      \&\\nx
      ..
      .y
 

Info Catalog groff: Writing Macros groff: Writing Macros groff: Parameters