browserenv - Go library to open a URL in a local web browser with support for the BROWSER environment variable

Age	Commit message (Collapse)	Author
2020-12-20	Add license (MPL 2.0)	Teddy Wing

2020-12-20	Set `pkg/browser`'s `Stderr` and `Stdout` to ours	Teddy Wing
	We need to connect our `Stderr` and `Stdout` to those in `github.com/pkg/browser` so that custom writers get linked correctly in the underlying library. Previously, customising these writers only worked for the command specified in the `BROWSER` environment variable, not when `BROWSER` was unset.
2020-12-20	browserenv_unix_test: Unset `BROWSER` in tests that set it	Teddy Wing
	The `BROWSER` environment variable value is carried over after each test, meaning if subsequent tests depend on it being undefined, they will fail. Unset the environment variable at the end of each test that sets it.
2020-12-20	Support multiple colon-separated commands in `BROWSER`	Teddy Wing
	After reading the `urlview` man page, I learned that it supports multiple commands in the `BROWSER` environment variable separated by colons. Read over the source to see what `urlview` does: https://github.com/sigpipe/urlview/blob/08767aa863cd27d1755ba0aff65b8cc1a0c1446a/urlview.c#L617-L630 It tries each command from left to right until one of them exits with a `0` exit code. Use the same logic here.
2020-12-20	Connect `Stdout` and `Stderr` to browser command	Teddy Wing
	Use the global `Stdout` and `Stderr` variables when running the command specified by `BROWSER`.
2020-12-20	Escape single quotes in URL	Teddy Wing
	On Unix, we escape the URL argument by surrounding it with single quotes. This fails if the URL contains single quotes. It also fails if the `BROWSER` command contains `%s` not surrounded by single quotes. Fix this by escaping the single quotes. We might also want to look into passing the `BROWSER` command and arguments into `exec.Command` directly instead of through `/bin/sh` and checking if that has an automatic escaping mechanism we can take advantage of.
2020-12-20	Handle `%s` format string for URL in `BROWSER` variable	Teddy Wing
	The `BROWSER` environment variable might contain a `%s` format string that should be replaced by the URL to open. If it's present perform the replacement. Otherwise, append the URL to the `BROWSER` command as before.
2020-12-20	TestBrowserCommand: Convert to table-driven test	Teddy Wing
	So we can add other test cases.
2020-12-19	Add `BROWSER` support to `OpenURL()`	Teddy Wing
	If the `BROWSER` environment variable is set, open the given URL using the command specified in the variable. Run the command in a shell process, either from the `SHELL` environment variable or `/bin/sh` on Unix OSes. Run it through `cmd` on Windows. Essentially repurposes my code from https://github.com/pkg/browser/pull/14.