6 ms·

For years I wanted a Bash prompt which would show when a command actually ran. I don't mean that it would show the time when the prompt was written to the term

For years I wanted a Bash prompt which would show when a command actually ran. I don't mean that it would show the time when the prompt was written to the terminal. That's easy. I mean that it would show the time when the command entered at it was executed. Those two times can be very different. This little hack updates your Bash prompt with the current time when you execute a command. As someone who spends many hours every day in the terminal, it's improved my life. Maybe it can help you too.

kortex 6y ago
Have you tried zsh with histdb? It's been an absolute gamechanger. Having a complete, precise, and effectively infinite history is like a second brain. I know not everyone is on the zsh train, but it might be able to be ported to bash (it's just pre-hooks and some sqlite) https://github.com/larkery/zsh-histdb https://github.com/larkery/zsh-histdb
- countermeasure 6y ago
  Bash is the only shell I've ever used, but one day when time permits I'm looking forward to taking zsh for a test drive.
- deadbunny 6y ago
  A quick Google turns up this [1]. Haven't verified it works though. 1. https://github.com/thenewwazoo/bash-history-sqlite https://github.com/thenewwazoo/bash-history-sqlite
  - kortex 6y ago
    Oh! I actually used this before switching to histdb. IIRC it works-ish but there was less polish than histdb.
- jjt-yn_t 6y ago
  started using it. Thanks.
nicwolff 6y ago
This is handy, but if you just want the ability to see when you ran a previous command you can add export HISTTIMEFORMAT="%d/%m/%y %T " to your .bashrc and then history will show the date and time before each command that was run.
- ansible 6y ago
  I had no idea! I was about to try out the linked article, but this is all I really need. Excellent!
  - countermeasure 6y ago
    I recommend using both approaches together. With an updating prompt, you can see when a command ran without having to type 'history'. And adding a date/time stamp to history is very useful when you need to go back further - hours, days or months.
- countermeasure 6y ago
  Excellent point. Seeing when a command in the history list was run is very useful. My preference is just for a date in the history, rather than date and time. I find that when I'm searching history, date is usually granular enough for me, so I can omit the time and save a little bit of screen real estate.
- blago 6y ago
  I've had this for a while and I noticed at least two problems on my mac: 1) It made the history command run much, much slower (I have HISTSIZE=100000) 2) Dates tend to reset to a uniform but meaningless value. I think it's related to OS reboots.
- kyuudou 6y ago
  I'm sure most know this but if anyone thinks this is a way of doing forensics, keep in mind it can be easily skipped over by doing a non-standard logout, like "kill -9 $$" or if a remote ssh connection gets cut for whatever reason. The command history for a session won't get written until logout by default. A workaround such as forcing each entry to be written to a log file will have to be done to have better assurance of true history.
deleted 6y ago
[deleted]
tiny_epoch 6y ago
I've had the following in my ~/.bash_profile for quite some time. I leave it here in the hopes it help someone. ## History configuration, see HISTORY in bash(1) ## builtin fc, aka fix command, for history manipulation ## fc [-e ename] [-lnr] [first] [last] ## -e or invoke editor ename; defaults to $FCEDIT ## -l or list commands ## -n or suppress entry numbers ## -r or reverse command order ## first, last selects a range of entries by numeric index ## ## fc -s [pat=rep] [cmd] ## -s or substitute all occurences of pat with rep # # - h() is short for history # - r() is short for replay # - always append to the history, don't overwrite # - save multi-line commands in a single entry # - insist on vim everywhere # - don't record commands with a leading space or duplicates # - constrain the size of the history file # - ignore common things # - constrain the number of history entries # - set up nicer timestamps alias h="history" alias r="fc -s" shopt -s histappend shopt -s cmdhist export FCEDIT=$EDITOR export HISTCONTROL=ignoreboth export HISTFILE=$HOME/.bash_history export HISTFILESIZE=1048576 export HISTIGNORE='ls:ls -l:ls -latr:ps -ef:fc:h:history:clear:exit' export HISTSIZE=8192 export HISTTIMEFORMAT='[%F %T] '
- chrisweekly 6y ago
  Thanks, @tiny_epoch -- that was helpful. :)

kortex 6y ago

Have you tried zsh with histdb? It's been an absolute gamechanger. Having a complete, precise, and effectively infinite history is like a second brain. I know not everyone is on the zsh train, but it might be able to be ported to bash (it's just pre-hooks and some sqlite) https://github.com/larkery/zsh-histdb https://github.com/larkery/zsh-histdb

countermeasure 6y ago
Bash is the only shell I've ever used, but one day when time permits I'm looking forward to taking zsh for a test drive.
deadbunny 6y ago
A quick Google turns up this [1]. Haven't verified it works though. 1. https://github.com/thenewwazoo/bash-history-sqlite https://github.com/thenewwazoo/bash-history-sqlite
- kortex 6y ago
  Oh! I actually used this before switching to histdb. IIRC it works-ish but there was less polish than histdb.
jjt-yn_t 6y ago
started using it. Thanks.

nicwolff 6y ago

This is handy, but if you just want the ability to see when you ran a previous command you can add export HISTTIMEFORMAT="%d/%m/%y %T " to your .bashrc and then history will show the date and time before each command that was run.

ansible 6y ago
I had no idea! I was about to try out the linked article, but this is all I really need. Excellent!
- countermeasure 6y ago
  I recommend using both approaches together. With an updating prompt, you can see when a command ran without having to type 'history'. And adding a date/time stamp to history is very useful when you need to go back further - hours, days or months.
countermeasure 6y ago
Excellent point. Seeing when a command in the history list was run is very useful. My preference is just for a date in the history, rather than date and time. I find that when I'm searching history, date is usually granular enough for me, so I can omit the time and save a little bit of screen real estate.
blago 6y ago
I've had this for a while and I noticed at least two problems on my mac: 1) It made the history command run much, much slower (I have HISTSIZE=100000) 2) Dates tend to reset to a uniform but meaningless value. I think it's related to OS reboots.
kyuudou 6y ago
I'm sure most know this but if anyone thinks this is a way of doing forensics, keep in mind it can be easily skipped over by doing a non-standard logout, like "kill -9 $$" or if a remote ssh connection gets cut for whatever reason. The command history for a session won't get written until logout by default. A workaround such as forcing each entry to be written to a log file will have to be done to have better assurance of true history.

deleted 6y ago

[deleted]

tiny_epoch 6y ago

I've had the following in my ~/.bash_profile for quite some time. I leave it here in the hopes it help someone. ## History configuration, see HISTORY in bash(1) ## builtin fc, aka fix command, for history manipulation ## fc [-e ename] [-lnr] [first] [last] ## -e or invoke editor ename; defaults to $FCEDIT ## -l or list commands ## -n or suppress entry numbers ## -r or reverse command order ## first, last selects a range of entries by numeric index ## ## fc -s [pat=rep] [cmd] ## -s or substitute all occurences of pat with rep # # - h() is short for history # - r() is short for replay # - always append to the history, don't overwrite # - save multi-line commands in a single entry # - insist on vim everywhere # - don't record commands with a leading space or duplicates # - constrain the size of the history file # - ignore common things # - constrain the number of history entries # - set up nicer timestamps alias h="history" alias r="fc -s" shopt -s histappend shopt -s cmdhist export FCEDIT=$EDITOR export HISTCONTROL=ignoreboth export HISTFILE=$HOME/.bash_history export HISTFILESIZE=1048576 export HISTIGNORE='ls:ls -l:ls -latr:ps -ef:fc:h:history:clear:exit' export HISTSIZE=8192 export HISTTIMEFORMAT='[%F %T] '

chrisweekly 6y ago
Thanks, @tiny_epoch -- that was helpful. :)