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Printout a list of field numbers (awk index) from a CSV file with headers as first line.
Useful to identify the field number in big CSV files with large number of fields. The index is the reference to use in processing with commands like 'cut' or 'awk' involved.

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.

pdfcount: get number of pages in a PDF file

Report the established connections for a particular port

cooking a list of numbers for calculation
When you've got a list of numbers each on its row, the ECHO command puts them on a simple line, separated by space. You can then substitute the spaces with an operator. Finally, pipe it to the BC program.

Remove all .svn folders
-depth argument will cause find to do a "depth first" tree search, this will eliminate the "No such file or directory" error messages

checks size of directory & delete it if its to small
only simple example how to combine rclone & jq

Use CreationDate metadata on .mov files to rename and modify the created/modify file dates on Mac

Get all IPs via ifconfig
Fetches the IPs and ONLY the IPs from ifconfig. Simplest, shortest, cleanest. Perl is too good to be true... (P.S.: credit should go to Peteris Krumins at catonmat.net)

Calculates the number of physical cores considering HyperThreading in AWK
Check whether hyperthreading is enabled or not. a better solution as nproc should work on all OS with awk


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