Commands by vonElfensenf (1)

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See a full list of compiler defined symbols
From http://lists.debian.org/debian-devel/2001/01/msg00971.html .

Run a program transparently, but print a stack trace if it fails
For automated unit tests I wanted my program to run normally, but if it crashed, to add a stack trace to the output log. I came up with this command so I wouldn't have to mess around with core files. The one downside is that it does smoosh your program's stderr and stdout together.

copy root to new device
Clone a root partition. The reason for double-mounting the root device is to avoid any filesystem overlay issues. This is particularly important for /dev. Also, note the importance of the trailing slashes on the paths when using rsync (search the man page for "slash" for more details). rsync and bash add several subtle nuances to path handling; using trailing slashes will effectively mean "clone this directory", even when run multiple times. For example: run once to get an initial copy, and then run again in single user mode just before rebooting into the new disk. Using file globs (which miss dot-files) or leaving off the trailing slash with rsync (which will create /mnt/target/root) are traps that are easy to fall into.

Encryption file in commad line
This will encrypt your single file and create a filename.gpg file. Option: * -c : Encrypt with symmetric cipher To decrypt dhinesh@ubuntu:~$ gpg -c sample.rb.gpg

Adding formatting to an xml document for easier reading
Sometimes you're trying to read through an xml file to determine whats wrong with it and a tool had removed all the linebreaks. xmllint will go ahead and make it pretty for you.

Batch File Rename with awk and sed

find files ignoring .svn and its decendents
for when find . -print | grep -v .svn | xargs doesnt cut it.

Count the total number of files in each immediate subdirectory
counts the total (recursive) number of files in the immediate (depth 1) subdirectories as well as the current one and displays them sorted. Fixed, as per ashawley's comment

Runs previous command but replacing
Replaces the first instance of 'foo' with 'bar'. To replace all instances of 'foo' with 'bar': !!:gs/foo/bar/

Instant mirror from your laptop + webcam (fullscreen+grab)
This directly puts the "mirror" into fullscreen, and lets you take photos by pressing the 's' key. I bet appearance conscious people will have keyboard shortcut for this command by now.


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