Node:Side by Side Format, Next:Example Side by Side, Up:Side by Side
The -y or --side-by-side option selects side by side
format. Because side by side output lines contain two input lines, the
output is wider than usual: normally 130 print columns, which can fit
onto a traditional printer line. You can set the width of the output
with the -W columns or --width=columns
option. The output is split into two halves of equal width, separated by a
small gutter to mark differences; the right half is aligned to a tab
stop so that tabs line up. Input lines that are too long to fit in half
of an output line are truncated for output.
The --left-column option prints only the left column of two
common lines. The --suppress-common-lines option suppresses
common lines entirely.