The content of this blog is my personal opinion only. Although I am an employee - currently of Imagination Technologies's MIPS group, in the past of other companies such as Intellectual Ventures, Intel, AMD, Motorola, and Gould - I reveal this only so that the reader may account for any possible bias I may have towards my employer's products. The statements I make here in no way represent my employer's position, nor am I authorized to speak on behalf of my employer. In fact, this posting may not even represent my personal opinion, since occasionally I play devil's advocate.

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Friday, September 07, 2012

Find latest version of tool on path

Frustrated by systems where there isn't a single order of bin directories that can arrange for the most recent version of tools to be used, I wrote a tool to find the latest version of a tool on the path:

~/bin/path-version -latest -verbose --version -print -exec bash -c 'echo hi from bash $($SHELL -version)'
/home/glew/bin/bash: 3.2.25(1)-release
/usr/local/bin/bash: 2.05a.0(2)-release
/bin/bash: 3.2.25(1)-release
latest: /home/glew/bin/bash: 3.2.25(1)-release
exec /home/glew/bin/bash, -c echo hi from bash $($SHELL -version);
hello /bin/bash -c echo hi from bash $($SHELL -version)
hi from bash GNU bash, version 3.2.25(1)-release (x86_64-redhat-linux-gnu) Copyright (C) 2005 Free Software Foundation, Inc.

--version (or -v, or -V, or -version) is the knob passed to the tool to query its version.

you can print all version, just the most recent, or just exec.


Based on a Perl library I just wrote, Version_Numbers.pm, that parses Version number strings of several syntaxes.  I.e. not just Perl's, and not just 1.2.3

I was surprised not to find such a library already existing.  Some were close, but not quite there.

Also compares.  Although the comparison rules are  a it two simplistic: strings are lexically sorted, whereas possibly

1.2rc should be less recent than 1.2, if the latter is what actually got released.