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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"

Make a ready-only filesystem ?writeable? by unionfs
First look into /etc/modules if you have unionfs (or squashfs) support. If not, add the modules. UnionFS combines two filesystems. If there is a need to write a file, /tmp/unioncache will be used to write files (first create that directory). Reads will be done where the file is found first. http://tldp.org/HOWTO/SquashFS-HOWTO/creatingandusing.html

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"

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.

Export unpushed files list

Migrate Server with rsync
Copies the complete root-dir of a linux server to another one, where the new harddisks formated and mountet. Very useful to migrate a root-server to another one.

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"

print file without duplicated lines using awk
This create an array 'a' with wole lines. only one occurrence of each line - Not Get lines ++ !

Split huge file into DVD+R size chunks for burning
Real DVD+R size is 4700372992 bytes, but I round down a little to be safe. To reconstitute use cat. "cat file.img.gz.aa file.img.gz.ab ..... > file.img.gz"

How to estimate the storage size of all files not named *.[extension] on the current directory
With this sentence we can estimate the storage size of all files not named *.jpg on the current directory. The syntax is based on Linux, for Unix compliance use: find ./* -prune ! -name '*.jpg' -ls |awk '{TOTAL+=$7} END {print int(TOTAL/(1024^2))"MB"}' We can change the jpg extension for whatever extension what we need


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