↓Skip to main content
IT Blog IT Blog
  1. All Posts/

semver-tool

Tools Shell

The semver shell utility

semver is a little tool to manipulate version bumping in a project that
follows the semver 2.x specification. Its uses are:

  • bump version
  • extract specific version part
  • compare versions
  • identify most significant difference between two versions
  • validate version syntax

It can be combined with git pre-commit hooks to guarantee correct versioning.

installation

The semver tool can be downloaded from github and made executable with these commands:

# Download the script and save it to /usr/local/bin
wget -O /usr/local/bin/semver 
  https://raw.githubusercontent.com/fsaintjacques/semver-tool/master/src/semver

# Make script executable
chmod +x /usr/local/bin/semver

# Prove it works
semver --version
# semver: 3.4.0

Most likely, you will want to insure that the directory containing semver is on your PATH.
See installation alternatives below.

usage 

Usage:
  semver bump major <version>
  semver bump minor <version>
  semver bump patch <version>
  semver bump prerel|prerelease [<prerel>] <version>
  semver bump build <build> <version>
  semver bump release <version>
  semver get major <version>
  semver get minor <version>
  semver get patch <version>
  semver get prerel|prerelease <version>
  semver get build <version>
  semver get release <version>
  semver compare <version> <other_version>
  semver diff <version> <other_version>
  semver validate <version>
  semver --help
  semver --version

Arguments:
  <version>  A version must match the following regular expression:
             "^[vV]?(0|[1-9][0-9]*).(0|[1-9][0-9]*).(0|[1-9][0-9]*)(-(0|[1-9][0-9]*|[0-9]*[A-Za-z-][0-9A-Za-z-]*)(.(0|[1-9][0-9]*|[0-9]*[A-Za-z-][0-9A-Za-z-]*))*)?(+[0-9A-Za-z-]+(.[0-9A-Za-z-]+)*)?$"
             In English:
             -- The version must match X.Y.Z[-PRERELEASE][+BUILD]
                where X, Y and Z are non-negative integers.
             -- PRERELEASE is a dot separated sequence of non-negative integers and/or
                identifiers composed of alphanumeric characters and hyphens (with
                at least one non-digit). Numeric identifiers must not have leading
                zeros. A hyphen ("-") introduces this optional part.
             -- BUILD is a dot separated sequence of identifiers composed of alphanumeric
                characters and hyphens. A plus ("+") introduces this optional part.

  <other_version>  See <version> definition.

  <prerel>  A string as defined by PRERELEASE above. Or, it can be a PRERELEASE
            prototype string followed by a dot.

  <build>   A string as defined by BUILD above.

Options:
  -v, --version          Print the version of this tool.
  -h, --help             Print this help message.

Commands:
  bump      Bump by one of major, minor, patch; zeroing or removing
            subsequent parts. "bump prerel" (or its synonym "bump prerelease")
            sets the PRERELEASE part and removes any BUILD part. A trailing dot
            in the <prerel> argument introduces an incrementing numeric field
            which is added or bumped. If no <prerel> argument is provided, an
            incrementing numeric field is introduced/bumped. "bump build" sets
            the BUILD part.  "bump release" removes any PRERELEASE or BUILD parts.
            The bumped version is written to stdout.

  get       Extract given part of <version>, where part is one of major, minor,
            patch, prerel (alternatively: prerelease), build, or release.

  compare   Compare <version> with <other_version>, output to stdout the
            following values: -1 if <other_version> is newer, 0 if equal, 1 if
            older. The BUILD part is not used in comparisons.

  diff      Compare <version> with <other_version>, output to stdout the
            difference between two versions by the release type (MAJOR, MINOR,
            PATCH, PRERELEASE, BUILD).

  validate  Validate if <version> follows the SEMVER pattern (see <version>
            definition). Print 'valid' to stdout if the version is valid, otherwise
            print 'invalid'.

See also:
  https://semver.org -- Semantic Versioning 2.0.0

examples

Basic bumping operations

$ semver bump patch 0.1.0
0.1.1
$ semver bump minor 0.1.1
0.2.0
$ semver bump patch 0.2.0
0.2.1
$ semver bump major 0.2.1
1.0.0
$ semver bump patch 1.0.0
1.0.1
$ semver bump prerel rc.1 1.0.1
1.0.1-rc.1
$ semver bump prerelease rc.1 1.0.1
1.0.1-rc.1
$ semver bump prerel rc.. 1.2.0-beta2
1.2.0-rc.1
$ semver bump prerel 1.0.1-rc.1+build4423
1.0.1-rc.2
$ semver bump prerel beta. 1.1.0-beta2
1.1.0-beta3
$ semver bump build build.051 1.0.1-rc1.1.0
1.0.1-rc1.1.0+build.051
$ semver bump release v0.1.0-SNAPSHOT
0.1.0

Comparing version for scripting

$ semver compare 1.0.1-rc1.1.0+build.051 1.0.1
-1
$ semver compare v1.0.1-rc1.1.0+build.051 V1.0.1-rc1.1.0
0
$ semver compare 1.0.1-rc1.1.0+build.051 1.0.1-rc1.1.0+build.052
0
$ semver compare 1.0.1-rc1.1.0+build.051 1.0.1-rb1.1.0
1
$ semver compare 10.1.4-rc4 10.4.2-rc1
-1
$ semver compare 10.1.4-rc4 10.4.2-1234
-1

Find most significant difference

$ semver diff 1.0.1-rc1.1.0+build.051 1.0.1
prerelease
$ semver diff 10.1.4 10.1.4

$ semver diff 10.1.4-rc4 10.4.2-rc1
minor

Extract version part

$ semver get patch 1.2.3
3
$ semver get minor 1.2.3
2
$ semver get major 1.2.3
1
$ semver get prerel 1.2.3-rc.4
rc.4
$ semver get prerelease 1.2.3-rc.4
rc.4
$ semver get prerel 1.2.3-alpha.4.5
alpha.4.5
$ semver get build 1.2.3-rc.4+build.567
build.567
$ semver get release 1.2.3-rc.4+build.567
1.2.3
$ semver get prerel 1.2.3+build.568

$ semver get prerel 1.2.3-rc.4+build.569
rc.4
$ semver get prerel 1.2.3-rc-4+build.570
rc-4

Validate

$ semver validate 1.0.0
valid
$ semver validate 1
invalid

installation alternatives

The manual installation of the semver tool is simple: just place a single file where you want it.
Sometimes,
however, alternative installation mechanisms might be desired. Two such methods are referenced below.

asdf

asdf is a tool version manager.
See the asdf documentation explaining how to set up asdf, install plugins and tools, and how to set/select versions.
The semver plugin handles the installation of the semver-tool. The plugin README file contains an example installation.

bpkg

bpkg is a lightweight bash package manager.
It takes care of fetching the shell scripts, installing them appropriately,
setting the execution permission and more.
The semver tool can be installed by running:

bpkg install -g semver-tool

git

Clone this repo (or download a specific release). Then, make install will (by default–this can be changed) install semver in /usr/local/bin.

developing semver

We welcome anyone wishing to contribute to semver. Contributions can be new functionality, bug fixes, improvements to documentation, examples of usage (gists).
This is a small and rather simple tool: only one source file! So, it’s not too hard to get started. A good starting place might be looking at the open issues.
Of course, submitting issues without being an active contributor is fine too. Just be aware that issues that basically ask for someone to add something usually don’t get much traction: it’s always good to explain why it’s a good idea,
how you would use it (i.e. your use-case), how other alternatives are not as good.
For a small project, there is a bit of rigor:

  • Kick off a potential contribution by submitting an issue. It should solicit comments. Proposing a path forward is always good. Issues are often an “intention to submit a pull request”.
  • Being a semantic versioning tool, we are sort of sensitive to breaking changes, compatibility. Consistency is (almost) never a bad thing.
  • Tests are expected. We even test documentation.
  • Commit messages should explain what was changed, why, design choices.
  • Readable code–including comments, consistent formatting, reasonable names–along with good commit messages makes
    reviewing work a pleasure. It also means that new contributors can ramp up quickly and old folks can…


↑