Commands by sdblepas (1)

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Kill all processes that listen to ports begin with 50 (50, 50x, 50xxx,...)
Run netstat as root (via sudo) to get the ID of the process listening on the desired socket. Use awk to 1) match the entry that is the listening socket, 2) matching the exact port (bounded by leading colon and end of column), 3) remove the trailing slash and process name from the last column, and finally 4) use the system(…) command to call kill to terminate the process. Two direct commands, netstat & awk, and one forked call to kill. This does kill the specific port instead of any port that starts with 50. I consider this to be safer.

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"

Recursive find and replace file extension / suffix (mass rename files)
Find recursively all files in ~/Notes with the extension '.md' and pipe that via xargs to rename command, which will replace every '.md' to '.txt' in this example (existing files will not be overwritten).

Find the package that installed a command

Monitor a file's size

Search recursively to find a word or phrase in certain file types, such as C code
I have a bash alias for this command line and find it useful for searching C code for error messages. The -H tells grep to print the filename. you can omit the -i to match the case exactly or keep the -i for case-insensitive matching. This find command find all .c and .h files

Convert CSV to JSON with miller
Using the csv tool `miller` you can transform a csv file into a json array of objects, where the properties are the values of the csv header line and the values are the values of the subsequent lines.

play audio stream and video stream in two different mplayer instances
Sometimes audio and video are not sync'ed. The factor 1.0884 is the quotient 48000/44100. One mplayer plays the audio file in the background, the other the video in the foreground. You can dump the audio file before with another commandlinefu

Rename .JPG to .jpg recursively
This command is useful for renaming a clipart, pic gallery or your photo collection. It will only change the big caps to small ones (on the extension).

list block devices
Shows all block devices in a tree with descruptions of what they are.


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