Commands by valessiobrito (3)

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Remove all unused kernels with apt-get
Remove old kernels (*-generic and *-generic-pae) via apt-get on debian/ubuntu based systems. Tested on ubuntu 10.04 - 12.04.

Search through all installed packages names (on RPM systems)
You can use wildcard with rpm search but you have to do 2 things: 1. use "-a" switch (means "all") with query ("-q") switch - argument is a pattern to use while searching for package names of all installed packages 2. protect wildcards, so that shell could not eat them - escape it with backslash ("\") or enclose all pattern between apostrophes ("'"): $ rpm -qa 'co*de' As you can see above it is possible to insert wildcards into middle of the pattern. If you want, you can add "-i" or another rpm query options, "-i" will print package information for all installed packages matching pattern.

Fetch the Gateway Ip Address
This is to fetch the Gateway Ip Address of a machine. Use the below format to put the value in a variable if you wish to find the gateway ip in a script $GATEWAY=$(netstat -nr | awk 'BEGIN {while ($3!="0.0.0.0") getline; print $2}')

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Time conversion/format using the date command

Search some text from all files inside a directory

Determining the excat memory usages by certain PID
this command gives you the total number of memory usuage and open files by the perticuler PID.

Mortality Countdown
watch the seconds of your life tick away - replace YYYY-mm-dd HH:MM:ss w/ your birthtime.

Apply fade effect to a audio
fade [type] fade-in-length [stop-time [fade-out-length]] Apply a fade effect to the beginning, end, or both of the audio. An optional type can be specified to select the shape of the fade curve: q for quarter of a sine wave, h for half a sine wave, t for linear (`triangular') slope, l for logarithmic, and p for inverted parabola. The default is logarithmic. A fade-in starts from the first sample and ramps the signal level from 0 to full volume over fade-in-length sec? onds. Specify 0 seconds if no fade-in is wanted. For fade-outs, the audio will be truncated at stop-time and the signal level will be ramped from full volume down to 0 starting at fade-out-length seconds before the stop-time. If fade-out-length is not specified, it defaults to the same value as fade-in-length. No fade-out is performed if stop-time is not specified. If the file length can be determined from the input file header and length-changing effects are not in effect, then 0 may be specified for stop-time to indicate the usual case of a fade-out that ends at the end of the input audio stream. All times can be specified in either periods of time or sample counts. To specify time periods use the format hh:mm:ss.frac format. To specify using sample counts, specify the number of samples and append the letter `s' to the sample count (for example `8000s').

list your device drivers
great for running off a bootable cd to identify hardware other os's can't detect


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