Q. How do I search old command history under bash shell? How do I display or modify previous commands?
A. Almost all modern shell allows you to search command history if enabled by user. Use history command to display the history list with line numbers. Lines listed with with a * have been modified by user.
Shell history search command
Type history at a shell prompt:
$ history
Output:
Sample output:
6 du -c
7 du -ch
8 ls [01-15]*-2008
9 ls -ld [01-15]*-2008
10 ls -ld [1-15]*-2008
11 ls -ld [0]*-2008
12 ls -ld [01]*-2008
13 rm -vrf [01]*-2008
14 du -ch
15 ls
16 cd
17 umount /mnt
18 df -H
19 vnstat
20 yum update
21 vnstat -m
22 vnstat -m -i eth0
....
...
996 ping router.nixcraft.in
997 ssh vivek@p1.vpn.nixcraft.in
998 alias
999 ~/scripts/clean.rss --fetch
1000 vnstat
1001 ~/scripts/clean.rss --update
To search particular command, enter:
$ history | grep command-name
$ history | egrep -i 'scp|ssh|ftp'
Emacs Line-Edit Mode Command History Searching
To get previous command containing string, hit [CTRL]+[r] followed by search string:
(reverse-i-search):
To get previous command, hit [CTRL]+[p]. You can also use up arrow key.
CTRL-p
To get next command, hit [CTRL]+[n]. You can also use down arrow key.
CTRL-n
fc command
fc stands for either “find command” or “fix command. For example list last 10 command, enter:
$ fc -l 10
To list commands 130 through 150, enter:
$ fc -l 130 150
To list all commands since the last command beginning with ssh, enter:
$ fc -l ssh
You can edit commands 1 through 5 using vi text editor, enter:
$ fc -e vi 1 5
Delete command history
The -c option causes the history list to be cleared by deleting all of the entries:
$ history -c
18 comment
hopefully looking for some tricks
To run a command whose number you know…
!203
Runs the 203rd command in history
You can press + and type some command:
For example
‘+ cd’
immediately apear the last command that match with ‘cd’ if you press + again, you can brows trough all the cd commands you has entered in your history
this dint work on ubuntu 4 me!!
didn’t wont on mint either
These r really helpful to every Linux user.
This acts as a guide for us… :-)
plz tell me that how we a order make
How to clear history in sh?
Does fc command clears history?
how to know the full history of shell from the starting of first day
Is there a way to retrieve command history in a shell script?
No. Within a script, the history mechanism is disabled.
How to recover cleared history again..??
I mean after pressing history -c..Please Help Me.:)
Thanks. Awesome summary.
make a entry of
hgrep () {
history | egrep –color=auto –recursive “$@”
}
In .bashrc file.
it will allow you to search history like
history ssh
output:
21 ssh openerp@odoo.openies.com
22 ssh openerp@odoo.openies.com
26 ssh root@odoo.openies.com
its really very helpful, Thanks yaar
To get history in a shell script, I’ve had to resort to this:
alias cmd=’history | shell_script’
Then I just create a function:
function shell_script {
}
and history is available.
Another approach is to read the history file:
grep somepattern $HISTFILE
However, its contents will be unreliable if you are running multiple shells.
I usually search command history with this alias:
alias gh=’history|grep’
I misspoke….
Either I create an alias that pipes history into the shell command
OR
I create a function() that has access to the current history – the function could be the entire script, or it could pipe the command history, possibly filtered, to the script.