Common Source
- common_source.sh
Cross OS compatible common values files
There are many differences between bash scripts between Windows (using mingw/cygwin), macOS (which uses a MODIFIED version of bash 3.2), and the many versions of Linux out there, that primarily use bash 4+. In addition to the shell behaving different, many pieces of basic information are retrieved in different ways, such as the kind of OS, number of processor cores, etc… This sets a collection of variables to try and normalize these behaviors for other vsi scripts to use, no matter what OS they are running on.
Note
Should be Bourne Shell compatible, not just Bourne again shell compatible.
- VSI_OS
Operating system name
Lowercase representation of the Operating system name. Based off of the OSTYPE environment variable, which is always defined in Bourne Shell.
Example
Values include linux, darwin, windows, bsd, solaris, and unknown
Note
Only systems that are not EOL are considered. For example, Windows 95 doesn’t have the wmic used, but is pass end-of-life, so it is not a concern.
See also
- VSI_PATH_ESC
Path escape string for windows path translation
MSYS2, Git for Windows, etc.. translate unix style paths to windows style for you when even you call a non-bash command. This helps bridge the gap between the unix style systems and windows. However, sometimes it translates too much, which can cause a lot of issue.
This environment variable exists to add a / on Windows, and null on all other OSes
Example
foo -v /tmp:/tmp
Becomes
foo -v C:/Users/user/AppData/Temp:C:/Users/user/AppData/Temp
But what you really might want is
foo -v C:/Users/user/AppData/Temp:/tmp
Using VSI_PATH_ESC
foo -v /tmp:${VSI_PATH_ESC}/tmp
Becomes
foo -v C:/Users/user/AppData/Temp://tmp
Note
Cygwin does not automatically translate paths, you have to explicitly call cygpath, so VSI_PATH_ESC is set to null. Using cygwin will take a lot more work, and is usually less preferred for this reason
Bugs
There is a // artifact left over when there should be a /. This usually does not cause problems, but on rare occasions it does. It is ugly on all occasions.
- VSI_MUSL
- Value:
0- Not a musl libc OS1- Is a musl libc based OS-1- Unable to determine
Checks to see if this is a musl based operating system. Inspect the grep executable for the string “musl”. If it is found, like on alpine, then this is marked as a musl libc OS 1, else 0.
- VSI_DISTRO
Name of the distribution.
For the various Linux distributions, it is often hard to know what OS you are dealing with. VSI_DISTRO will tell you the name of the distribution, which is typically all lowercase (in all test cases). Many different versions store the distribution name in different locations—only most modern Linux distributions use the standard /etc/os-release, but many LTS distributions that are not EOL (end-of-life) use less standard methods. This variable checks all of these known possibilities.
Note
Other OSes like Windows, Mac, BSD, and solaris will have something set to VSI_DISTRO
OS |
VSI_DISTRO |
|
|---|---|---|
Windows |
windows |
(same as VSI_OS) |
BSDs |
${OS_TYPE} |
(expected bsd*, freebsd*) |
Solaris |
${OS_TYPE} |
(expected solaris*) |
Mac |
darwin |
(same as VSI_OS) |
See also
- VSI_DISTRO_VERSION
The version of the distribution
Note
For non-Linux distributions, this is the same as the VSI_OS_VERSION
Understanding Windows versions
10.0
Windows 10 and Windows Server 2016
6.3
Windows 8.1 and Windows Server 2012R2
6.2
Windows 8 and Windows Server 2012
6.1
Windows 7 and Windows Server 2008R2
6.0
Windows Vista and Windows Server 2008
5.2
Windows XP x64 and Windows Server 2003 and 2003R2
5.1
Windows XP
5.0
Windows 2000 and Windows 2000 Server
4.0
Windows NT 4.0 and Windows NT 4.0 Server
3.51
Windows NT 3.51 and Windows NT 3.51 Server
3.5
Windows NT 3.5 and Windows NT 3.5 Server
3.10
Windows NT 3.1 and Windows NT 3.1 Server
——————- NT line
4.90
Windows Me
4.10
Windows 98
4.00
Windows 95
3.2
Windwos 3.2
3.11
Windwos 3.11
3.10
Windows 3.1
3.00
Windows 3.0
2.11
Windows 2.11
2.10
Windows 2.10
2.03
Windows 2.03
1.04
Windows 1.04
1.03
Windows 1.03
1.02
Windows 1.02
1.01
Windows 1.01
- VSI_DISTRO_LIKE
Name of the distribution this distribution is based off of
Some os-release files typically have an ID_LIKE to specify which distribution it was based off of. For example Ubuntu is based off of debian and Mint is based off of Ubuntu. This captures and stores that “like” behavior.
This is not as useful as the VSI_DISTRO_CORE which is more useful in determining “should I use yum or apt, etc…”
See also
- VSI_DISTRO_VERSION_LIKE
Version of VSI_DISTRO_LIKE
The version release (number when possible) of the VSI_DISTRO_LIKE. This is not as useful as VSI_DISTRO_VERSION_CORE for determining things such as “For this fedora based distributions, should I be using dnf or yum”. If it was centos, _LIKE would be rhel, and _CORE would be fedora, and then all you would need to check is if the fedora version (VSI_DISTRO_VERSION_CORE) is >= 22 or not.
See also
- VSI_DISTRO_CORE
Name of the distribution this distribution is based off of
Unlike VSI_DISTRO_LIKE, VSI_DISTRO_CORE will tell you the distribution that this distribution is REALLY based off of. For example, centos is “like” rhel but they are both really fedora at the core. Which means they use yum, etc. This is what really matters for a lot of logic that you would be using these variables in the first place.
While the _LIKE variable identifies the parent distribution, _CORE should identify the progenitor, typically debian, fedora, slackware, gentoo, etc…
See also
- VSI_DISTRO_VERSION_CORE
Version of VSI_DISTRO_CORE
The version of the VSI_DISTRO_CORE that the distribution is based off of
See also
- VSI_OS_VERSION
Version of the operating system
For the Windows operating systems, this is the same as VSI_DISTRO_VERSION. For Linux/Unix based operating systems, this will evaluate to the kernel version
See also
- VSI_ARCH
System architecture
The architecture of the CPU in use (same as uname -m)
Example
Possible values include (but may not be limited to)
i386 i686 x86_64 ia64 alpha amd64 arm armeb armel hppa m32r m68k mips
mipsel powerpc ppc64 s390 s390x sh3 sh3eb sh4 sh4eb sparc
Typically found: x86_64
- VSI_NUMBER_CORES
Determines the number of CPU cores available on the machine.