vercmp/README

69 lines
1.9 KiB
Plaintext

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