CLI
$BASH_SOURCE is the call stack of scripts with the top of the stack being the currently executing sourced script, sourcing another script from the current one will push it on top of the stack. To get an idea of how this works you can set up a directory tree
CLI
Most foolproof method I'm aware of is the following: SCRIPTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd && echo x)" SCRIPTDIR="${SCRIPTDIR%x}" or if you're not worried about newlines at the end of your directory names: SCRIPTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )" How does this work? In the first example
CLI
Sometimes a bunch of unwanted files end up somewhere they don't belong. Maybe a cp gone wrong, or other command line typo creates a slew of oddly named files -- but you've got a number of files you'd really like to keep around mixed in with the bad. The following
CLI
If you keep your database backed up into a single SQL dump and want to retrieve only the part matching one database, perhaps to transfer to another system, I find the simplest and most re-usable trick is to use sed's "p" function which prints the "pattern space" to STDOUT even
CLI
One of the neat tricks of exec is that you can use it to redirect all output from a shell. If you take advantage of this inside of a script you can easily send all your output to a file, or even syslog. #!/bin/bash # redirect STDOUT to a file
CLI
Feel left out of the Instagram craze? Everyone else is sharing pictures of their food and all you have is code. Not to worry InstaCode [http://instacod.es] has you covered: [http://instacod.es/79356]
CLI
I like to have a pretty obvious indication of the success of failure of any commands I might have run. To accomplish this I add several color coding shortcuts to my .bash_profile: RED='\033[0;31m' GREEN='\033[0;32m' BLUE='\033[0;34m' NOFORMAT='\
Perl
What does use strict; in Perl really get you? By default three things, which can be specified separately or turned off separately: # All on by default when using use strict; use strict "vars"; use strict "subs"; use strict "refs"; # One or more can be turned off if need be no
Bash
The environment variable $LINENO contains the current line number of the running BASH shell. On the command line the value will be the number of command line prompts you've used in that shell, but in a script it's the currently executing line -- and it really is line number, if
Perl
Usually when you access a hash you get a single scalar value back, but it's also possible to get an array of values back - a slice of the hash. To do this all you have to do is pass in an array of keys, rather then a single key,
CLI
I decided to refresh my Dropbox install on Fedora 17 (now Fedora 18) from scratch and found the documentation of how to do that from the CLI a little conflicted. Here are the steps that worked for me. Run the following commands as the user you want to be your
Backups
I'm currently using s3sync [http://s3sync.net/wiki%22], a ruby script that gives rsync like functionality with Amazon's S3 service, to store some of my more irreplaceable data. However it looks like maintenance of the program has become a bit spotty. The latest updated version can be found on