Commands by savagemike (1)

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Rename files in batch

Get full directory path of a script regardless of where it is run from
Also resolves symlinks, showing the full path of the link target

Runs previous command replacing foo by bar every time that foo appears
Very useful for rerunning a long command changing some arguments globally. As opposed to ^foo^bar, which only replaces the first occurrence of foo, this one changes every occurrence.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Keep a copy of the raw Youtube FLV,MP4,etc stored in /tmp/
Certain Flash video players (e.g. Youtube) write their video streams to disk in /tmp/ , but the files are unlinked. i.e. the player creates the file and then immediately deletes the filename (unlinking files in this way makes it hard to find them, and/or ensures their cleanup if the browser or plugin should crash etc.) But as long as the flash plugin's process runs, a file descriptor remains in its /proc/ hierarchy, from which we (and the player) still have access to the file. The method above worked nicely for me when I had 50 tabs open with Youtube videos and didn't want to have to re-download them all with some tool.

Optimize PDF documents

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

strip config files of comments
some configuration files, particularly those installed by default as part of a package, have tons of comment lines, to help you know what's possible to configure, and what it means. That's nice, but sometimes you just want to see what specifically what _has_ been configured. That's when I use the above snippet, which I save as a bash alias 'nocom' (for 'no comments'). Apache default config files are perfect examples of when/why this script is handy.

Copy via tar pipe while preserving file permissions (cp does not!; run this command with root!)
cp options: -p will preserve the file mode, ownership, and timestamps -r will copy files recursively also, if you want to keep symlinks in addition to the above: use the -a/--archive option

Intercept, monitor and manipulate a TCP connection.
This will handle multiple incoming connections. Also, found sed works best with -u flag (unbuffered io). Easiest way I've found to get ncat is to install nmap.


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