displays contents of two files in three
columns. Column1 contains lines that occur only in file1. Column2
contains lines that occur only in file2. Column3 contains lines found
in both files. The optional -c argument suppresses output of column(s)
c, i.e. using -12 will print only the lines found in both files.
date
prints the current time and date.
cal [month year]
prints corresponding calendar. If cal is
invoked with no arguments, then it prints the current month's calendar.
look string
prints all words that begin with string.
ispell file
interactive spelling program checks spelling in file.
history
prints numbered history of commands invoked within the shell.
!n executes the command. bf !-n executes the last
command. !! repeats the last command (equivalent to !-1).
script filename
records all screen I/O into filename until
you type exit. Note that if filename already exists as a file, it
will be overwritten by script.
uname -a
prints characteristic information of the machine you are
working on.