Commands using diff

on a dpkg managed system this PATTERN will help you generate .deb files from source AND remove all the dev libs you had to install. i hate cluttering up my machine with rouge packages and headers.

it would be pretty darn easy on rpm systems as well. i just dont have a rpm managed system to test on right now.

NOTE, you sharp ones will notice that it uninstalls the deb you just made! yeah, but the deb is still there to do with it what you want, like re install it. or you can just grep -v after the diff

This only works in bash

If you like to view what has been changed between revision 100 and the BASE on FILE. Meld will give you a nice overview.

Will colorize your svn diff.

This command takes a snapshot of the open files for a PID 1234 then waits 10 seconds and takes another snapshot of the same PID, it then displays the difference between each snapshot to give you an insight into what the application is doing.

This will cause diff to ignore any files whose path matches "*CVS*", ie any CVS control files.

This is useful when you're diffing two files of the same name in radically different directory trees. For example:

Set

then

then run the command. Much easier on the eyes when you're looking back across your command history, especially if you're doing the same diff over and over again.

Makes sure the contents of "myfile" are the same contents that the author intended given the author's md5 hash of that file ("c84fa6b830e38ee8a551df61172d53d7").

Figures out what has changed in the last 12 hours.

Change the author to yourself, change the time since to whatever you want.

I sometimes (due to mismanagement!) end up with files in a git repo which have had their modes changed, but not their content. This one-liner lets me revert the mode changes, while leaving changed-content files be, so I can commit just the actual changes made.

This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.

A x509 certificate and a rsa key file have in common a parameter called modulus, it is a very long hexadecimal number.

That value is unique for each certficate / key pair.

The command allows to do the check of this pair of values in a script using a great feature of bash. "

Only shows files with actual changes to text (excluding whitespace). Useful if you've messed up permissions or transferred in files from windows or something like that, so that you can get a list of changed files, and clean up the rest.

diff is designed to compare two files. You can also compare directories. In this form, bash uses 'process substitution' in place of a file as an input to diff. Each input to diff can be filtered as you choose. I use find and egrep to select the files to compare.

:q to quit

You got some results in two variables within your shell script and would like to find the differences? Changes in process lists, reworked file contents, ... . No need to write to temporary files. You can use all the diff parameters you'll need. Maybe anything like $ grep "^>"

is helpful afterwards.

Handy when you need to create a list of files to be updated when subversion is not available on the remote host. You can take this tar file, and upload and extract it where you need it. Replace M and N with the revisions specific to yours. Make sure you do this from an updated (svn up) working directory.

Simple way to achieve a colored SVN diff

Lists revisions in a Subversion repository with a timestamp that doesn't follow the revision numbering order. If everything is OK, nothing is displayed.

It can be hard to spot differences in reformatted files, because of all the diff noise created by word wrapped lines. This command removes all the noise and performs a word-by-word diff. To ignore empty lines, add -B to the diff command. Also, if this is something you do often, you might want to check out the wdiff(1) program.

This uses Bash's "process substitution" feature to compare (using diff) the output of two different process pipelines.