flag: better option parser

[techtonik]

There is a problem with command line usability of go. From #12197:

• no long options like --help or --verbose
• -h has a strict position, e.g. go get something -h doesn't work, only go get -h something
• go get -h help is unreadable - lacks visual structure

There are more features that could be added to stdlib. Tools:

https://github.com/jawher/mow.cli
https://github.com/codegangsta/cli

[bradfitz]

The behavior of Go's flag package is intentional.

[techtonik]

@bradfitz it is not about changing flag behavior. Python also still ships with a getopt, but rarely who uses that.

[adg]

@techtonik as a counterpoint: in my opinion the go tools' command line interface is well-defined, well-documented, and consistent. I can't really relate to your criticisms, except that it is a bit different to what you might be used to.

[ianlancetaylor]

@techtonik The go standard flag package has made deliberate design choices. Those seem unlikely to change. At any rate, they would only change after a discussion of benefits and costs.

It is straightforward to write a different flag parsing package in Go, and to use that in your own programs. In fact, I'm sure it has been done, e.g., http://godoc.org/code.google.com/p/getopt .

[techtonik]

@adg maybe it is just a habit developed because there is no anything else in daily practice to compare with? =)