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Control VirtualBox VMs in OSX

List VMs and their state VBoxManage list vms -l | grep -e ^Name: -e ^State | sed "s/Name:[ ]*\(.*\)/\1 \//;s/State:[\ ]*//" | paste -d " " - - Start VM in headless mode VBoxManage startvm <vm> --type headless Stop VM (clean) VBoxManage controlvm <vm> acpipowerbutton Stop

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Set up a HTTP server in current directory

Use Python 2.x python -m SimpleHTTPServer 8080 Use Python 3.x python -m http.server 8080

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Build a Raspberry Pi toolchain in OSX

Create and mount case-sensitive image hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 16g -volname crosstool-ng ~/crosstool-ng.dmg hdiutil attach ~/crosstool-ng.dmg.sparseimage -mountpoint /Volumes/crosstool-ng Download a toolchain configuration mkdir /tmp/my-toolchain-config && cd /tmp/my-toolchain-config Download the desired Raspberry Pi platform configuration. Available configurations

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Create and apply a file patch

Create a file patch with differences diff -Naur <original> <changed> > my-patch.patch Apply file patch patch -p1 < my-patch.patch

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Install Crosstool-NG in OSX

Download Crosstool-NG 1.22.0 wget https://github.com/crosstool-ng/crosstool-ng/archive/crosstool-ng-1.22.0.tar.gz Unpack and change directory tar -zxf crosstool-ng-1.22.0.tar.gz && \ cd crosstool-ng-crosstool-ng-1.22.0 Bootstrap configuration and configure ./bootstrap && \ ./configure --prefix=/opt/crosstool-ng \ --with-sed=/opt/local/bin/gsed

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Trace HTTP packets in OSX

Trace all HTTP packets with destination port 80 ngrep -q -W byline -d <network interface> '' 'dst port 80'

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Calculate checksums of a file in OSX

Calculate MD5 checksum md5sum <file> Calculate SHA-1 checksum shasum -a 1 <file> Calculate SHA-256 checksum shasum -a 256 <file>

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Docker cleanup

Kill all running containers docker kill $(docker ps -q) Remove all stopped containers docker rm $(docker ps -a -q) Remove all untagged images docker rmi -f $(docker images -q -f dangling=true) Remove all images docker rmi -f $(docker images -q)

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Backup and restore a SD card in OSX

List and unmount disk sudo diskutil list sudo diskutil unmountDisk /dev/disk2 Backup SD card sudo dd if=/dev/rdisk2 of=./sd_card.img bs=4m Restore SD card sudo diskutil list sudo diskutil unmountDisk /dev/disk2 sudo dd if=./sd_card.img of=/dev/rdisk2 bs=4m

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tar commands for xz format

Compress file (maximum compression ratio) XZ_OPT=-9e tar cJf file.tar.xz file Uncompress file (keep original file) tar xJfk file.tar.xz

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Programmer competency matrix

http://sijinjoseph.com/programmer-competency-matrix/

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What makes a good engineering culture?

1. Optimize for iteration speed. 2. Push relentlessly towards automation. 3. Build the right software abstractions. 4. Develop a focus on high quality code with code reviews. 5. Maintain a respectful work environment. 6. Build shared ownership of code. 7. Invest in automated testing. 8. Allot 20% time 9. Build