If you have used bash for any scripting, you've used the date command alot. It's perfect for using as a way to create filename's dynamically within aliases,functions, and commands like below.. This is actually an update to my first alias, since a few commenters (below) had good observations on what was wrong with my first command.
# creating a date-based ssh-key for askapache.github.com
ssh-keygen -f ~/.ssh/`date +git-$USER@$HOSTNAME-%m-%d-%g` -C 'webmaster@askapache.com'
# /home/gpl/.ssh/git-gplnet@askapache.github.com-04-22-10
# create a tar+gzip backup of the current directory
tar -czf $(date +$HOME/.backups/%m-%d-%g-%R-`sed -u 's/\//#/g' <<< $PWD`.tgz) .
# tar -czf /home/gpl/.backups/04-22-10-01:13-#home#gpl#.rr#src.tgz .
I personally find myself having to reference
date --help
quite a bit as a result. So this nice alias saves me a lot of time. This is one bdash mofo. Works in sh and bash (posix), but will likely need to be changed for other shells due to the parameter substitution going on.. Just extend the sed command, I prefer sed to pretty much everything anyways.. but it's always preferable to put in the extra effort to go for as much builtin use as you can. Otherwise it's not a top one-liner, it's a lazyboy recliner.
Here's the old version:
alias dateh='date --help|sed "/^ *%%/,/^ *%Z/!d;s/ \+/ /g"|while read l;do date "+ %${l/% */}_${l/% */}_${l#* }";done|column -s_ -t'
This trick from my [ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html bash_profile ]
Show Sample Output
Reuse the last parameter of the previous command line Show Sample Output
Can be used for command line parameters too.
If you have a more complicated way of entering values (validation, GUI, ...), then write a function i.e. EnterValue() that echoes the value and then you can write:
param=${param:-$(EnterValue)}
Then exit from the shell.
exit
some time need to exit twice
exit
exit
Now the OS will boot with the new parameters.
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