Bash history handling with multiple terminals
Solution 1
The bash session that is saved is the one for the terminal that is closed the latest. If you want to save the commands for every session, you could use the trick explained here.
export PROMPT_COMMAND='history -a'
To quote the manpage: “If set, the value is executed as a command prior to issuing each primary prompt.”
So every time my command has finished, it appends the unwritten history item to
~/.bash_history
before displaying the prompt (only $PS1) again.So after putting that line in
/etc/bash.bashrc
I don’t have to find myself reinventing wheels or lose valuable seconds re-typing stuff just because I was lazy with my terminals.
Anyway, you'll need to take into account that commands from different sessions will be mixed in your history file so it won't be so straightforward to read it later.
See also:
Solution 2
After multiple readings of man bash
, I use separate history files for each shell. I did a mkdir -m 0700 ~/.history
then added
[[ -d ~/.history ]] || mkdir --mode=0700 ~/.history
[[ -d ~/.history ]] && chmod 0700 ~/.history
HISTFILE=~/.history/history.$(date +%y%b%d-%H%M%S).$$
# close any old history file by zeroing HISTFILESIZE
HISTFILESIZE=0
# then set HISTFILESIZE to a large value
HISTFILESIZE=4096
HISTSIZE=4096
to my ~/.bashrc
. Every now and then, I remember to du -sk .history
and clean it out. It's nice to have every command I've typed preserved for me.
I just used the above to see what I'd been doing, of late:
cut -f1 "-d " .history/* | sort | uniq -c |sort -n -r |less
or
cut -f1-2 "-d " .history/* | sort | uniq -c |sort -n -r |less
(to include the 1st argument e.g. sudo mount
in the sort chain).
Solution 3
See also "keeping persistent history in bash" for another alternative. It rigs your prompt to send all commands ever typed into any terminal into a "persistent history" file (alongside what's usually done for the regular .history
).
Solution 4
To show history
from all terminals:
Add export PROMPT_COMMAND='history -a; history -r'
to your .bashrc file.
Source: http://northernmost.org/blog/flush-bash_history-after-each-command
Solution 5
History from all shell sessions is less useful than I hoped!
I enthusiastically set PROMPT_COMMAND='history -a; history -r'
in the hopes that my history usage would be much better!
Wow, was I disappointed.
Essentially, doing this makes up/dn arrow useless. Because now each history session is littered with commands from other sessions. And for me this loses the best feature of history.
What I really wanted
Occasionally, I wanted to essentially transfer my history from one terminal session to another session so I could easily recall commands from that session. And I can do this very selectively.
What I did
I set up a series of simple history manipulation aliases & I ignore these commands in the history:
alias ha="history -a"
alias hb="history -a; history -r"
alias hr="history -r"
alias hl="history | tail -20"
HISTIGNORE="ha:hb:hr:hl"
I think of hb
as history blend...the others are self-explanatory.
Now when I want to copy my history from session A to session B, I can do this:
-
A:
ha
- append session A history to history file -
B:
hb
- append session B history to history file and then read the file
This essentially preserves the history order for session B and adds session A history deeper in the list.
Super useful for me. Maybe helps you too!
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zetah
Updated on September 18, 2022Comments
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zetah over 1 year
I use mainly Terminator, and it's usually opened with 3 split terminal windows. I also use Gnome terminal for various reasons.
I'm wondering how is bash history handled in this case as I sometimes miss previously issued commands when I runhistory
For example, my prompt shows current bash history line (
\!
) and if I launch Terminator with 3 split terminal windows I get same history line (let's say 100) on all terminals. Which history will be saved?Also launching Gnome Terminal after using Terminator I get line 100 at startup regardless all commands issued before in Terminator
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Admin almost 5 yearsRelated on Unix SE: Preserve bash history in multiple terminal windows
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Admin over 3 yearsAlso consider this related question: stackoverflow.com/questions/14834786
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Vineet Menon over 12 yearsisn't it stored separately for different TTL??
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zetah over 12 yearsExcellent. Thanks for explanation and solution. I tried with
export PROMPT_COMMAND='history -a; history -r'
and I got some strange history line numbers in terminal - after issuing some command history line number jumps by 2000 instead by 1, which is strange but it behaves as said - all terminals history is saved. -
user2342005 over 11 yearsWhy do you assign
HISTFILESIZE
twice? -
goo over 11 yearsBy setting HISTFILESIZE to 0, I clear the history buffer and reset the history saving mechanism. Then, I set the size I really want, and start saving history in HISTFILE. See the HISTORY section of
man bash
. -
n611x007 about 11 yearsis there a way to merge the history files in order to make
Ctrl+r
work again? -
goo about 11 yearsThis should be a new question, but I don't think it's a Good Idea. I use
egrep 'whatever' .history/*
(orcat .history/* | egrep 'whatever'
) instead, and use Ctrl-r to search an individual session's history. Readman bash-builtins
about the history command. Mysort .history/* | uniq -c | sort -n | wc -l
shows 16033 unique commands,cut '-d ' -f1 .history/* | sort | uniq -c | sort -n
shows 2004 unique commands, mostly typos. Loading all that into bash's "history list" would not help. -
Elijah Lynn about 10 yearsI will say that after a couple months of using this I eventually commented this out just recently. It is bittersweet as I don't always want to sift through the last 100 commands just to run the one I had originally run in the Tmux pane I sometimes may have a dedicated log command in that I need to restart.
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Shubham over 6 yearsThis website seems down: northernmost.org/blog/flush-bash_history-after-each-command
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Evgeni Sergeev about 6 yearsI inserted $$ to make the line
echo $$ $date_part "$command_part" >> ~/.persistent_history
This prefixes the entries with the PIDs of their bash process, so that we can disentangle multiple histories. -
Elijah Lynn almost 6 yearsA nice solution that the fish shell offers is a
history --merge
. I have been using this for a year or so now and it solves the issue. When I want the most recent history from other sessions, I just run that command and it is available to me instantly. -
max over 5 yearsCan the alternative history be made to work with CTRL-R history search?
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unsynchronized about 5 years@waltinator - i know this is an old comment, but are you implying that setting an environment variable somehow triggers an immediate action? what process is going to pick up the fact you assigned a value of 0 to HISTFILESIZE in a local shell and then immediately change to 4096? is this something undocumented about bash's handling of certain variable names?
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Marc.2377 almost 5 years
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lmat - Reinstate Monica almost 5 years"won't be so straightforward to read it later." How do you work? I usually work on one terminal at a time following a thread of thought ;-) The history shouldn't be much worse than your train of thought...
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lmat - Reinstate Monica almost 5 years@Daniel To invoke the Deep Magic.
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lmat - Reinstate Monica almost 5 yearsexport is not needed.
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goo over 4 years@unsynchronized: See
man bash
, the part that starts withThe following variables are used by the shell.
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n1k31t4 over 4 years(+1) Is it actually necessary to first run
mkdir -m 0700 ~/.history
, then also include it in the second condition in your first line of the code block:[[ -d ~/.history ]] || mkdir --mode=0700 ~/.history
? Do the first two lines not ensure (with each new terminal when.bashrc
is executed) that the folder exists with the expected permissions? -
goo over 4 years@n1k31t4 No, not actually necessary, but included for documentation. It's easier to simply set the permission to "what's Right", than to check with
stat -c "%a" ~/.history/
and then fix it if it's wrong. Yes, the two lines ensure that, every time through~/.bashrc
, my~/.history
directory exists with the Right permissions. -
fooBar over 2 yearsUse
ctrl+R
to search your history from terminal, that will help with mixed shells...