vercmp

======



51 SLOC, not counting format scripts.



vercmp evaluates a version comparison expression and prints "yes" if the

expression evaluates to true and "no" otherwise.



vercmp can be extended with additional formats by adding a shell script defining

a `comparever` function to the `format` subdirectory.  no `format` subdirectory

is included by default.  to make bootstrapping easier, instructions for pulling

some are included in the makefile.  if bootstrapping lix os, for example, the

following will `git clone` lix os' vercmp formats into the format directory:



    make lix-os-formats



or, if wanting a basis for creating one's own formats using the same foundatiion

as lix os' formats:



    make bare-formats



to install, just `make install`.



usage:



    vercmp <comparison string> [format]

    vercmp formats



comparison string:

    "<version 1> <op> <version 2>"



op:

    == equal

    >= greater than or equal

    <= less than or equal

    >  greater than

    <  less than



format:

    the name of the format to use for parsing and comparing the versions.

	see 'vercmp formats' for a list of formats.

	(format scripts are kept in $VERCMPROOT/format)



## examples



    $ vercmp "1.2.3 >= 3.2.1"

    no



    $ vercmp "1.2 == 1.2"                                                                           

    yes



    $ vercmp "1.2+meta1 == 1.2+meta2"                                                               

    yes



    $ vercmp "1.2+meta1 > 1.2-rc1+meta2"                                                            

    yes



    $ vercmp "1.2-rc1 < 1.2-rc2"

    yes



## caveat



vercmp format scripts assume both versions are in the same format.  if this is

not the case, undefined behavior may ensue.  even a simple variation like the

following can have unexpected results:



     $ vercmp "1.2 == 1.2.0"                                                                         

     no