ehistory: Edit history file to re-execute commands

Package: language

Usage

ehistory (or just "e")

Parameters

None.

Description

The ehistory command calls up a screen editor to edit previously executed commands, executing the edited command when return is typed. Interrupt (e.g., <ctrl/c> may be used to escape from the editor at any time. The type of editor commands recognized is determined by the value of the CL environment variable editor, which may currently be set to "edt", "emacs", or "vi".

After the ehistory command is entered, the previous command is displayed at the bottom of the terminal. If the previous command was a compound statement, or if it extended over more than one line, all the lines of the command will be displayed. To reach a different command simply enter the appropriate cursor movement keys for the editor type being used. When the cursor attempts to move above the current command the previous command will be displayed. Similarly when it attempts to move below, the next command will appear. Hitting the return key will execute the command currently being edited.

The CL parameter "ehinit" may be used to set the following options:

[no]standout: Controls whether the command to be edited is displayed in reverse or normal video.

eol: The editor is entered with the cursor positioned to be end of the command line.

bol: The editor is entered with the cursor positioned to be beginning of the command line.

[no]verify: If verify is specified, ehistory will be automatically entered when history commands are entered to recall and execute previous commands. If noverify is specified, the commands are recalled and immediately executed.

Examples

1. Set no standout and verify modes.

cl> ehinit = "nostandout verify".

2. Recall the last "xc" command from the history list and edit it. If verify were not enabled the command would simply be repeated.

cl> ^xc

Bugs

The command editor really only works well for single line commands; multiline command blocks are not easily edited at present. VI is poorly emulated at present since only control code editor commands are possible.