![\"\"](\"http:\/\/cdblog.cdstealer.com\/wp-content\/uploads\/2011\/06\/gnometerminal.png\")
<\/p>\n<\/p>\n
Just a few things I find helpful :)<\/p>\n
This is more of an audit thing, but sometimes it's useful to know when you did something.<\/p>\n
If you type the command history<\/strong><\/em> into your shell. \u00a0You get back a list of the last X number of command executed.<\/p>\n But by adding the following to your ~\/.bashrc (local user) or \/etc\/bash\/bashrc (all users) file, you can inject the time\/date. \u00a0Please see\u00a0man date<\/strong><\/em> for the options you can use.<\/p>\n Example<\/p>\n It's an annoyance when you execute a command consecutively many time and then have to search further back to get to the last different command. \u00a0Behold! \u00a0Add this to your .bashrc(local user) or \/etc\/bash\/bashrc (all users) and no matter how many times you execute that command consecutively, it will only store the one time.<\/p>\n Example<\/p>\n Accidentally logging out of a shell session or user session can be annoying. \u00a0But there is hope :) \u00a0Add this to your .bashrc(local user) or \/etc\/bash\/bashrc (all users) and now you have to double tap to get out.<\/p>\n This one ideally needs to go into the \/etc\/bash\/bashrc or else it would only work when closing your own shell session.<\/p>\n Example<\/p>\n Extract Path or File<\/strong><\/p>\n\n\n\n Pop this at the top of a bash script. <\/p>\n","protected":false},"excerpt":{"rendered":" Just a few things I find helpful :) Bash history with timestamp. This is more of an audit thing, but sometimes it's useful to know when you did something. If you type the command history into your shell. \u00a0You get back a list of the last X number of command executed. $ history | tail … Continue reading Bash Shell Tips<\/span> $ history | tail -n1\n502 history | tail -n1<\/pre>\n
HISTTIMEFORMAT='%F %T '<\/pre>\n
$ history | tail -n1\n508 2017-01-14 11:29:58 history | tail -n1<\/pre>\n
\nBash History Duplicate Removal<\/h6>\n
HISTCONTROL=ignoreboth<\/pre>\n
user@server ~ $ vi .bashrc\nuser@server ~ $ vi .bashrc\nuser@server ~ $ vi .bashrc\nuser@server ~ $ vi .bashrc\nuser@server ~ $ history | tail -n5\n508 2017-01-14 11:29:58 history | tail -n1\n509 2017-01-14 11:31:36 man date\n510 2017-01-14 11:32:43 history\n511 2017-01-14 11:40:52 vi .bashrc\n512 \u00a02017-01-14 11:42:36 history | tail -n5<\/pre>\n
\nDouble tap exit\/logoff<\/h6>\n
IGNOREEOF=1<\/pre>\n
server ~ # Use \"logout\" to leave the shell.\nserver ~ # logout\nuser@server ~ $<\/pre>\n\n\n
$ export VAR=\/home\/me\/mydir\/file.c
$ echo \"${VAR%\/*}\"
\/home\/me\/mydir
$ echo \"${VAR##*\/}\"
file.c<\/pre>\n\n\n\nCron Execution Only<\/h6>\n\n\n\n
Eg. The below is for a cronjob that is executed at reboot:
# crontab -l
@reboot \/bin\/bash \/path\/to\/something\/bad.sh<\/p>\n\n\n\n#!\/usr\/bin\/env bash
if [[ ! $(< \/proc\/${PPID}\/comm) == cron* ]]; then
echo \"Do NOT manually execute this script. ONLY at reboot!!!!\"
exit
fi<\/pre>\n\n\n\n