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Remove grep itself from ps
When you 'ps|grep' for a given process, it turns out that grep itself appears as a valid line since it contains the RE/name you are looking for. To avoid grep from showing itself, simply insert some wildcard into process' name.

Extract the contents of an RPM package to your current directory without installing them.
This assumes you have the 'rpm', 'rpm2cpio' and 'cpio' packages installed. This will extract the contents of the RPM package to your current directory. This is useful for working with the files that the package provides without installing the package on your system. Might be useful to create a temporary directory to hold the packages before running the extraction: $ mkdir /tmp/new-package/; cd /tmp/new-package

set history file length
set how many commands to keep in history Default is 500 Saved in /home/$USER/.bash_history Add this to /home/$USER/.bashrc HISTFILESIZE=1000000000 HISTSIZE=1000000

Convert all .flac from a folder subtree in 192Kb mp3
find . -type f -iname '*.flac' # searches from the current folder recursively for .flac audio files | # the output (a .flac audio files with relative path from ./ ) is piped to while read FILE; do FILENAME="${FILE%.*}"; flac -cd "$FILE" | lame -b 192 - "${FILENAME}.mp3"; done # for each line on the list: # FILE gets the file with .flac extension and relative path # FILENAME gets FILE without the .flac extension # run flac for that FILE with output piped to lame conversion to mp3 using 192Kb bitrate

eDirectory LDAP Search for Statistics
Find statistics for an Edirectory server form LDAPsearch. We have a lot more examples at: http://ldapwiki.willeke.com/wiki/Ldapsearch%20Examples The full command got shut off it is: ldapsearch -h ldapserver.willeke.com -p636 -e C:\mydata\treerootcert.der -b "" -s base -D cn=admin,ou=administration,dc=willeke,dc=com -w secretpwd "(objectclass=*)" chainings removeEntryOps referralsReturned listOps modifyRDNOps repUpdatesIn repUpdatesOut strongAuthBinds addEntryOps compareOps wholeSubtreeSearchOps modifyEntryOps searchOps errors simpleAuthBinds inOps oneLevelSearchOps inBytes abandonOps bindSecurityErrors securityErrors unAuthBinds outBytes extendedOps readOps dsaName directoryTreeName vendorVersion vendorName

Convert any sequence of spaces/tabs to single space/tab
Remove empty lines additionally: $ tr -s ' \t\n' 2.txt identical with: $ tr -s '[:space:]' 2.txt To "clean perfectly" a text or code file, You can combine this command with another one: $ while read l; do echo -e "$l"; done 2.txt (= remove all leading and trailing spaces or tabs from all lines of a text file)

Find directories under home directory with 777 permissions, change to 755, and list them on console

Colorized grep in less
Get your colorized grep output in less(1). This involves two things: forcing grep to output colors even though it's not going to a terminal and telling less to handle those properly.

Execute a command with a timeout
I like much more the perl solution, but without using perl. It launches a backgroup process that will kill the command if it lasts too much. A bigger function: check_with_timeout() { [ "$DEBUG" ] && set -x COMMAND=$1 TIMEOUT=$2 RET=0 # Launch command in backgroup [ ! "$DEBUG" ] && exec 6>&2 # Link file descriptor #6 with stderr. [ ! "$DEBUG" ] && exec 2> /dev/null # Send stderr to null (avoid the Terminated messages) $COMMAND 2>&1 >/dev/null & COMMAND_PID=$! [ "$DEBUG" ] && echo "Background command pid $COMMAND_PID, parent pid $$" # Timer that will kill the command if timesout sleep $TIMEOUT && ps -p $COMMAND_PID -o pid,ppid |grep $$ | awk '{print $1}' | xargs kill & KILLER_PID=$! [ "$DEBUG" ] && echo "Killer command pid $KILLER_PID, parent pid $$" wait $COMMAND_PID RET=$? # Kill the killer timer [ "$DEBUG" ] && ps -e -o pid,ppid |grep $KILLER_PID | awk '{print $1}' | xargs echo "Killing processes: " ps -e -o pid,ppid |grep -v PID | grep $KILLER_PID | awk '{print $1}' | xargs kill wait sleep 1 [ ! "$DEBUG" ] && exec 2>&6 6>&- # Restore stderr and close file descriptor #6. return $RET }

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"


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