In standard Fortran 77, anything beyond column 72 is ignored.
Most compilers provide an option to change this (for example,
‘-ffixed-line-length-N’ in gfortran). Customize the variable
fortran-line-length to change the line length in Fortran mode.
Anything beyond this point is font-locked as a comment. (Unless it is
inside a string: strings that extend beyond
will confuse font-lock.)
Display a column ruler momentarily above the current line
Split the current window horizontally temporarily so that it is
fortran-line-length columns wide
fortran-window-create-momentarily). This may help you avoid
making lines longer than the limit imposed by your Fortran compiler.
Split the current window horizontally so that it is
fortran-line-length columns wide (
You can then continue editing.
Delete all text in column
fortran-line-length and beyond.
The command C-c C-r (
fortran-column-ruler) shows a column
ruler momentarily above the current line. The comment ruler is two lines
of text that show you the locations of columns with special significance in
Fortran programs. Square brackets show the limits of the columns for line
numbers, and curly brackets show the limits of the columns for the
statement body. Column numbers appear above them.
Note that the column numbers count from zero, as always in GNU Emacs. As a result, the numbers may be one less than those you are familiar with; but the positions they indicate in the line are standard for Fortran.
The text used to display the column ruler depends on the value of the
variable indent-tabs-mode. If indent-tabs-mode is
nil, then the value of the variable
fortran-column-ruler-fixed is used as the column ruler.
Otherwise, the value of the variable fortran-column-ruler-tab is
displayed. By changing these variables, you can change the column ruler
C-c C-w (
splits the current window horizontally, making a window
fortran-line-length columns wide, so you can see any lines that
are too long. Type a space to restore the normal width.
You can also split the window horizontally and continue editing with
the split in place. To do this, use C-u C-c C-w (
fortran-window-create). By editing in this window you can
immediately see when you make a line too wide to be correct Fortran.
The command M-x fortran-strip-sequence-nos deletes all text in
fortran-line-length and beyond, on all lines in the
current buffer. This is the easiest way to get rid of old sequence