Currently cli silently (aside from IntSlice and Int64Slice which oddly
printed directly to the error stream) ignores failures that occur when
parsing environment variables for their value for flags that define
environment variables. Instead, we should propogate up the error to the
user.
This is accomplished in a backwards compatible manner by adding a new,
internal, interface which defines an applyWithError function that all
flags here define. In v2, when we can modify the interface, we can drop
this secondary interface and modify `Apply` to return an error.
When assigning values to flags (also when interogatting via
`context.(Global)IsSet`.
For boolean flags, consider empty as `false`.
Using `syscall.Getenv` rather than `os.LookupEnv` in order to support
older Golang versions.
This has some benefits, but results in possibly less informative error
messaging; however, given that there are only two accepted types,
I think the error messaging is sufficient.
Most of the changes here remove trailing whitespace, but I also add
code to select "AUTHOR" or "AUTHORS" as appropriate instead of the
previous "AUTHOR(S)". The template for listing with an entry per line
is:
{{range $index, $entry := pipeline}}{{if $index}}
{{end}}{{$entry}}{{end}}
That range syntax is discussed in [1].
Also add a unit test, which tests both these whitespace changes and
also the earlier App.Description addition.
[1]: https://golang.org/pkg/text/template/#hdr-Variables
This code initially landed with lots of space:
'{name} <{email}> '
or:
'{name} '
in 3d718330 (app, help: add support for multiple authors, 2015-01-31).
The doubled space between the name and email was removed in c6592bb4
(app, help: add backwards compatibility for Authors, 2015-02-21), but
a trailing space remained in both the email and email-less cases.
This commit removes that trailing space.
In the unreleased version 2, the argument reordering has been removed
(in f585ec7cb8) since it only worked if
all of the arguments appeared before all of the flags, but not if they
were intermixed which was of limited utility and caused some confusion.
This commit allows enabling of this future behavior via SkipArgReorder.
Ideally we'd support complete intermingling of flags and arguments, but
this is unlikely to happen until we switch flag parsers.
Fixes#515
When checking if environment variables are set.
We don't support pointer flags currently (though this is the default in
the `v2` branch), but this fixes#516
Since we have `v1.X` tags, gopkg.in/urfave/cli.v1 will pull the latest
tagged release rather than the `v1` branch. Since there are no tagged
`v2` releases, `gopkg.in` will pull the latest commit of that branch.
Fixes#513
