Linux in a Nutshell, Fifth Edition

history | 669

Bash and Korn

This is the Title of the Book, eMatter Edition

Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

help

help [-s] [pattern]

Bash only. Print usage information on standard output for each

command that matches pattern. The information includes descrip-

tions of each command’s options. With the -s option, print only

brief usage information.

Examples

$ help -s cd Short help

cd: cd [-L|-P] [dir]

$ help true Full help

true: true

Return a successful result.

hist

hist [options] [first [last]]

hist -s [old=new] [command]

ksh93 only. Display or edit commands in the history list. (Use only

one of -l or -s.) first and last are numbers or strings specifying the

range of commands to display or edit. If last is omitted, hist applies

to a single command (specified by first). If both first and last are

omitted, hist edits the previous command or lists the last 16. The

second form of hist takes a history command, replaces old with

new, and executes the modified command. If no strings are speci-

fied, command is just reexecuted. If no command is given either, the

previous command is reexecuted. command is a number or string

like first. See the examples in the earlier section “Command

History.”

Options

-e [editor]

Invoke editor to edit the specified history commands. The

default editor is set by the shell variable HISTEDIT. If that

variable is not set, FCEDIT is used. If neither is set, ...