Merge pull request #82 from terminalforlife/master

More Goodies

sheets/_bash/forkbomb

@@ -6,3 +6,6 @@
 # function definition and then calls the function to begin the chain reaction.
 # A very nasty trick, indeed.
 :(){ :|: & };:
+
+# A more-readable version of the fork bomb could be written as:
+FORK(){ true | true & }; FORK

sheets/apt-cache

@@ -0,0 +1,9 @@
+# Search for package PKG. Both package names and their descriptions are searched
+# for a REGEX match; to avoid this behavior, you may use the `-n` flag, which will
+# only look for a match in the package name.
+apt-cache search 'PKG'
+
+# Regarding the above, although multiple package names may not be specified, it's
+# possible to use ERE to easily and quickly get around this limitation. Here, all
+# 3 packages (PKG1, PKG2, and PKG3) will be sought.
+apt-cache search '(PKG1|PKG2|PKG3)'

sheets/apt-get

@@ -0,0 +1,53 @@
+# Update the local database of available packages, as discovered from package index
+# file found in their sources. This does not actually update your installed
+# software! For that, keeping reading.
+apt-get update
+
+# Upgrade installed packages, but there may be exceptions, such as important kernel
+# packages. Also, packages will not be removed, like if they're deprecated, with
+# this method.
+apt-get upgrade
+
+# Unlike the above, this will upgrade all of the installed packages, and perform
+# other actions required for a successful and thorough upgrade. This will also
+# allow for upgrading to the next minor release of your distributions, such as from
+# Ubuntu '16.04.1' to '16.04.2'.
+apt-get dist-upgrade
+
+# Clean out (completely) the follow locations of saved DEB files:
+#
+#   /var/cache/apt/archives/* /var/cache/apt/archives/partial/
+#   /var/lib/apt/lists/partial/
+#   /var/cache/apt/pkgcache.bin /var/cache/apt/srcpkgcache.bin
+#
+# This will also, thanks to the provided flag, be somewhat verbose.
+sudo apt-get clean -s
+
+# View the changelog for the firefox package. Useful prior to or after upgrade.
+apt-get changelog firefox
+
+# Download PKG (one or more) without actually installing or extracting them. A good
+# use for this might be to upgrade an offline system, by downloading the packages
+# on a system using an Internet-able machine. Files are downloaded into the CWD.
+apt-get download PKG
+
+# Install PKG (one or more), bringing in dependencies and, provided settings allow
+# it, install recommended and/or suggested packages.
+apt-get install PKG
+
+# At times, dependencies won't be installed, yet you still need them; the following
+# command will often fix this, and is usually suggested to the user.
+apt-get -f install
+
+# Remove PKG, while also purging system-wide configuration files for it.
+apt-get purge PKG
+# Alternative syntax:
+apt-get remove --purge PKG
+
+# Often used to first update the local database of packages, then, only if
+# successful, a full system upgrade is started.
+apt-get update && apt-get dist-upgrade
+
+# Download specified package (firefox, in this example) and all packages marked
+# thereby as important or dependencies. Files are downloaded into the CWD.
+apt-get download firefox `apt-cache --important depends firefox | awk '{if(NR>1){printf("%s ", $2)}}'`

sheets/dpkg-deb

@@ -0,0 +1,10 @@
+# Build a DEB package using the provided directory.
+dpkg-deb -b /path/to/directory
+
+# List out the contents of an existing DEB package.
+dpkg-deb -c /path/to/package.deb
+
+# Extract the contents of an existing DEB package. If no destination is provided
+# for the extracted files, then they will be extracted to the CWD. Will also create
+# the specified directory if it's not found, but it won't create its parents.
+dpkg-deb -x /path/to/package.deb /path/to/destination/

sheets/source

@@ -0,0 +1,6 @@
+# This is a shell builtin available in bash, but not in the Bourne Shell (`sh`).
+# The contents of FILE (assuming shell script) will be sourced into the current
+# session, allowing external use of things like its functions and variables.
+source FILE
+# The above can be written in short-hand, for the same effect:
+. FILE

sheets/udisksctl

@@ -0,0 +1,20 @@
+# Output low-level information for the provided block device and partition.
+udisksctl info -b /dev/sdd1
+
+# Mount partition on the given block device. This will by default use '/media', and
+# on typical systems won't even require root privileges.
+udisksctl mount -b /dev/sd??
+
+# Set up a loop device using 'imagefile'. This only sets it up, so you will
+# probably also want to mount it thereafter, using the device given to you after
+# executing this command. often, if not always, this is '/dev/loopX', where X is
+# the loop device number.
+udisksctl loop-setup -f image file
+
+# Like the above, except this will delete the loop device (assuming 'loop0' was
+# previously created) but note that this will NOT delete the image file. Be sure to
+# unmount the filesystem(s) on the device first, before deleting it.
+udisksctl loop-delete -b /dev/loop0
+
+# Power off a block device. May not work for all devices, and may vary in effect.
+udisksctl power-off -b /dev/sdb

sheets/umask

@@ -0,0 +1,18 @@
+# Unless configured otherwise, this will set the umask ("user mask" or "file mode
+# creation mask") for only the current user, and only his or her current session.
+# The (one) leading zero is optional, unless you otherwise need it.
+#
+# This umask setting is actually recommended for security by RHEL, and is also
+# mentioned and I believe recommended in the Arch Linux Wiki.
+#
+# The result of '0077' being -- and I'll use standard octal with which we're all
+# probably familiar -- that all new files are created using the '600'
+# permissions, and directories are '700'.
+#
+# Remember, the standard format means 4=read, 2=write, and 1=execute. However, the
+# umask uses the same, but is inverted, so a umask of '077' would be 700, and
+# correctly lowers to 600 when it's just a file.
+umask 0077
+
+# Akin to above, but instead, output the current umask setting.
+umask