Using the Korn Shell

Turn on extended command history

To start recording the date and time that each command is executed, set the EXTENDED_HISTORY environment variable to ON:

                        export EXTENDED_HISTORY=ON
                        

                     

The CUT (Coordinated Universal Time) timestamp will be appended to each line of the ~/.sh_history file.

Display command history

The command history can be displayed with various history or fc (fix command) commands:

                        history
                        

                        fc -l
                        

                        history n​
                        

                        fc -l n​
                        

                        

                        fc -t
                        

                        history -t
                        

                        fc -t n​
                        

                        history -t n​
                        

                     

n specifies which command the listing is to start with. If it is negative, then the listing starts with the nth previous commmand; if it is non-negative, the listing starts with the specified command number. If -t is specified, the output will include the timestamps.

Repeat a previous command

                        r
                        

                     

without any parameters repeats the preceding command.

                        r searchtext​
                        

                     

repeats the last command starting with the given search text.

                        r -n​
                        

                     

repeats the nth previous command.

                        r n​
                        

                     

repeats the specified command. The number of a command can be determined by displaying the command history or by setting the prompt to include the command number.

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Last updated Tuesday October 3, 2006