Commands using bc (51)

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securely erase unused blocks in a partition
This command securely erases all the unused blocks on a partition. The unused blocks are the "free space" on the partition. Some of these blocks will contain data from previously deleted files. You might want to use this if you are given access to an old computer and you do not know its provenance. The command could be used while booted from a LiveCD to clear freespace space on old HD. On modern Linux LiveCDs, the "ntfs-3g" system provides ReadWrite access to NTFS partitions thus enabling this method to also be used on Wind'ohs drives. NB depending on the size of the partition, this command could take a while to complete.

Display the top ten running processes - sorted by memory usage

Rename all .jpeg and .JPG files to .jpg

Play random music from blip.fm

send kernel log (dmesg) notifications to root via cron
this is helpful because dmesg is where i/o errors, etc are logged to... you will also be able to see when the system reboots or someone attaches a thumb drive, etc. don't forget to set yourself up in /etc/aliases to get roots email.

Get creation date of a file on ext2-3-4 fs
Return the creation date of a file on ext2, 3, 4 filesystems, because stat command won't show it. Useful on ubuntu, debian, and else

Load your [git-controlled] working files into the vi arglist.
Branch name may be substituted, of course.

Search recursively to find a word or phrase in certain file types, such as C code
I have a bash alias for this command line and find it useful for searching C code for error messages. The -H tells grep to print the filename. you can omit the -i to match the case exactly or keep the -i for case-insensitive matching. This find command find all .c and .h files

Selecting a random file/folder of a folder
Also looks in subfolders

Measures download speed on eth0


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