feature-check1
Query a program for supported features
Usage
feature-check [-v]
[-O
optname]
[-P
prefix]
program
feature-name
feature-check [-O
optname]
[-P
prefix]
program
feature-name
op
version
feature-check [-O
optname]
[{-o
json | tsv}]
[-P
prefix]
-l
program
feature-check {-V | -h}
feature-check --features
Overview
The feature-check tool obtains the list of supported features from a program via various methods (e.g. running it with the --features command-line option) and allows other programs to check for the presence and, possibly, versions of specific features.
Options:
-
--features -
List the compile-time features supported by this version of
feature-check:- feature-check
-
Always present, with the version of the
feature-checktool. - list
-
Present if the
feature-checktool supports fetching the list of features supported by a program. - simple
-
Present if the
feature-checktool supports comparing the version of a single feature against a specified version string. - single
-
Present if the
feature-checktool supports querying a single feature.
-
-h, --help -
Display program usage output and exit.
-
-O optname -
Specify the option to pass to the program to obtain its list of features (default
--features). -
-o format -
Specify the output format for the full list of features with the
-loption. -
-P prefix -
Specify the prefix that
feature-checkshould look for in the program's output to find the line that contains the list of features; default "Features: ". -
-V, --version -
Display program version output and exit.
-
-v -
When querying a single feature, output the version obtained for it.
Exit status
When querying a single feature, feature-check will exit with code 0 if the program supports that feature, and with a non-zero code when either the program could not be executed, or its list of features could not be parsed, or the feature was not present.
When examining the version of a single feature, feature-check will exit with code 0 if the comparison result is true, and with a non-zero code when either the program could not be executed, or its list of features could not be parsed, or the comparison failed.
When listing the features supported by a program, feature-check will exit with code 0 when the list of features was obtained and output, and with a non-zero code when either the program could not be executed or its list of features could not be parsed.
Examples
The following examples are shown as given to the shell:
feature-check curl AsynchDNS
Exit with code 0 if the curl(1) tool is present and it supports asynchronous DNS lookups.
feature-check -l confget
List the features supported by the confget(1) tool.
feature-check timelimit 'timelimit ge 1.9'
Exit with code 0 if the timelimit(1) tool advertises its timelimit feature at version 1.9 or later.
feature-check timelimit timelimit ge 1.9
The same check; note that the feature-check tool will treat all the arguments after the program name as a single expression, i.e. it will concatenate them into a single string separated by spaces and then interpret the string.
Releases
4 releases since Debian 10 (Buster); the text changed 1 time.