Scripting

My 10 most used linux commands

This is a oneliner bash command to determine my 10 most used linux commands according to my history file history | awk ‘{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] ” ” CMD[a]/count*100 “% ” a;}’ | grep -v “./” | column -c3 -s ” ” -t | sort -nr | nl | head -n10 The […]

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Linux

Allow NFS through iptables

This is one way to determine the ports needed to open in your iptables rules to get NFS to work properly. First we need to determine the ports NFS uses rpcinfo -p | awk -F ” ” ‘{print $3 “, ” $4 “, ” $5}’ | sort | uniq Notice! Since portmap assigns ports on […]

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Linux

Query RPM database/packages and list their architecture

If you use the –queryformat argument with rpm it is possible to query RPMs for different architectures installed# rpm -qa –queryformat %{NAME}-%{VERSION}-%{ARCH}\\n | grep dbus-glib | sortResultdbus-glib-0.22-12.EL.5-i386dbus-glib-0.22-12.EL.5-x86_64This can also be used in one of my previous posts: Remove duplicate packages when querying the rpm database.

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Scripting

Sort IP address

Sorting IP addresses using sort is not easy because the dot confuses sort. This line makes it possible to sort by the whole value of the address sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k 4,4 ipaddresses.txt You can also sort by the last octet sort -r. -n +3.0 ipaddresses.txt

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Linux

List processes in a hierarchy

ps -e -o pid,args –forest List processes by % cpu usage ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu | sed ‘/^ 0.0 /d’ List processes by mem usage ps -e -orss=,args= | sort -b -k1,1n | pr -TW$COLUMNS List info for particular process IDs ps -p 1,2

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