optimize your shell environment
Here are some random improvements to the shell (bash) environment that I like to use on the servers I manage. You can simply add the code snippets to your .profile file.
how to show more information in process list
You can improve the information that the ps command shows by default by setting the environment variable PS_FORMAT:
export PS_FORMAT='user,pid,ppid,tty,pcpu,pmem,stat,thcount,start,time,cmd'
prevent accidental overwrite by output redirect
It is easy to accidentially overwrite a file by redirecting the output of a command into a file that already exists. If you add
set -o noclobber
to your bash profile, you safe yourself from a lot of trouble. if you want to overwrite a file intentionally, you can use >| instead of a simple >. Here's an example:
$ ls > tmpfile $ ls > tmpfile bash: tmpfile: cannot overwrite existing file $ ls >| tmpfile
ignore some files or directories for tab completion
Some directories, like e.g. .svn should not be taken into account for tab completion of file names. Put them in a colon separated list in the environment variable FIGNORE:
export FIGNORE='.svn:~'
control how bash handles the history
Tell bash to save ignore dulicates in saving the history.
export HISTCONTROL=ignoredups
You can set HISTIGNORE to a colon separated list of commands that shall not be saved in the history.
export HISTIGNORE="ls:exit:bg:fg"
Make history immediately available from all bash instances:
shopt -s histappend