Linux Delete a Single Line from History

This post will guide you how to delete a single line from bash shell history in Linux system. How to delete/clear a certain line or command from bash history file under Linux system. How to delete history command of last 10 commands in bash shell.

Linux Delete a Single Line from History

If you want to check the history with line number in bash shell, you just need to execute the history command, type:

#history

Outputs:

70 hwinfo --bios
71 man hwinfo
72 ls /etc/xxxx
73 ls /etc/xxxx 2>fio.txt
74 cat fio.txt
75 find -name *.txt ./
76 find ./ -name *.txt
77 find /etc -name *.conf
78 find /etc -name a*.conf
79 ls
80 cd tmp
81 ls
82 find /tmp -name a*.conf
83 find / -name a*.conf
84 cd
85 find / -name a*.conf &> fio.txt
86 cat fio.txt
87 history

From the above output, you will see that the line number and the commands have been displayed.

Delete a Specified Command from History

If you only want to delete or remove a specified command from the bash shell history, you need to execute the history command with the –d option, and then pass to the line number of command that you want to delete.

Type the following command:

#history –d 86

Delete All History Command or Line

If you want to delete or remove all history command from bash shell, you just run the history command with –c option, type:

# history –c

Outputs:

root@ubuntu-dev:~# history -c
root@ubuntu-dev:~# history
1 history

Get more information about History command

If you want to get more information about history command, you can check it man page of history command or just use help command to get the usage of history command.

Type the following command:

#man history

Or

#help history

Outputs:

root@ubuntu-dev:~# help history
history: history [-c] [-d offset] [n] or history -anrw [filename] or history -ps arg [arg...]
Display or manipulate the history list.

Display the history list with line numbers, prefixing each modified
entry with a `*'. An argument of N lists only the last N entries.

Options:
-c clear the history list by deleting all of the entries
-d offset delete the history entry at offset OFFSET.

-a append history lines from this session to the history file
-n read all history lines not already read from the history file
-r read the history file and append the contents to the history
list
-w write the current history to the history file
and append them to the history list

-p perform history expansion on each ARG and display the result
without storing it in the history list
-s append the ARGs to the history list as a single entry

If FILENAME is given, it is used as the history file. Otherwise,
if $HISTFILE has a value, that is used, else ~/.bash_history.

If the $HISTTIMEFORMAT variable is set and not null, its value is used
as a format string for strftime(3) to print the time stamp associated
with each displayed history entry. No time stamps are printed otherwise.

Exit Status:
Returns success unless an invalid option is given or an error occurs.

Delete History of Last 10 Commands

If you want to delete last 10 commands from bash shell history, you can use the following simple shell command:

#for h in $(seq $(history | tail -1 | awk '{print $1-N}')  $(history | tail -1 | awk '{print $1}') | tac); do history -d $h; done; history -d $(history | tail -1 | awk '{print $1}')

You just need to update the value of N to 10. And it will delete the last 10 commands from history.

Or you can run the following command to get your current history to get the line number of last 10 commands:

#history | tail –n 10

The outputs like below:

[root@devops ~]# history | tail -n 10
171 rpm -qi wget
172 rpm -qip wget-1.14-10.el7.x86_64.rpm
173 rpm -qdf wget
174 rpm -Vp wget-1.14-10.el7.x86_64.rpm
175 rpm -e wget
176 rpm -Vp wget-1.14-10.el7.x86_64.rpm
177 ls /etc/pki/rpm-gpg/
178 rpm -qa gpg-pubkey*
179 history
180 history | tail -n 10

So you should know the start and end positions for the last 10 commands that you want to delete. It’s 171 to 180. Then executing the second command to delete last 10 commands:

# for i in $(seq 171 180 | tac); do history -d $i; done

This command will generate history –d commands for 180, then 179, then 171.