diff options
| -rw-r--r-- | README.md | 19 | ||||
| -rw-r--r-- | parse.go | 2 | ||||
| -rw-r--r-- | parse_test.go | 6 | ||||
| -rw-r--r-- | usage.go | 8 | ||||
| -rw-r--r-- | usage_test.go | 4 |
5 files changed, 28 insertions, 11 deletions
@@ -120,6 +120,23 @@ $ WORKERS='1,99' ./example Workers: [1 99] ``` +You can also have an environment variable that doesn't match the arg name: + +```go +var args struct { + Workers int `arg:"--count,env:NUM_WORKERS"` +} +arg.MustParse(&args) +fmt.Println("Workers:", args.Workers) +``` + +``` +$ NUM_WORKERS=6 ./example +Workers: 6 +$ NUM_WORKERS=6 ./example --count 4 +Workers: 4 +``` + ### Usage strings ```go var args struct { @@ -594,7 +611,7 @@ https://godoc.org/github.com/alexflint/go-arg There are many command line argument parsing libraries for Go, including one in the standard library, so why build another? -The `flag` library that ships in the standard library seems awkward to me. Positional arguments must preceed options, so `./prog x --foo=1` does what you expect but `./prog --foo=1 x` does not. It also does not allow arguments to have both long (`--foo`) and short (`-f`) forms. +The `flag` library that ships in the standard library seems awkward to me. Positional arguments must precede options, so `./prog x --foo=1` does what you expect but `./prog --foo=1 x` does not. It also does not allow arguments to have both long (`--foo`) and short (`-f`) forms. Many third-party argument parsing libraries are great for writing sophisticated command line interfaces, but feel to me like overkill for a simple script with a few flags. @@ -90,7 +90,7 @@ func mustParse(config Config, dest ...interface{}) *Parser { p, err := NewParser(config, dest...) if err != nil { fmt.Fprintln(config.Out, err) - config.Exit(-1) + config.Exit(2) return nil } diff --git a/parse_test.go b/parse_test.go index 07af7ed..5bc781c 100644 --- a/parse_test.go +++ b/parse_test.go @@ -703,7 +703,7 @@ func TestMustParseError(t *testing.T) { os.Args = []string{"example"} parser := MustParse(&args) assert.Nil(t, parser) - assert.Equal(t, -1, exitCode) + assert.Equal(t, 2, exitCode) assert.Contains(t, stdout.String(), "default values are not supported for slice or map fields") } @@ -921,7 +921,7 @@ func TestParserMustParse(t *testing.T) { }{ {name: "help", args: struct{}{}, cmdLine: []string{"--help"}, code: 0, output: "display this help and exit"}, {name: "version", args: versioned{}, cmdLine: []string{"--version"}, code: 0, output: "example 3.2.1"}, - {name: "invalid", args: struct{}{}, cmdLine: []string{"invalid"}, code: -1, output: ""}, + {name: "invalid", args: struct{}{}, cmdLine: []string{"invalid"}, code: 2, output: ""}, } for _, tt := range tests { @@ -1571,7 +1571,7 @@ func TestMustParseInvalidParser(t *testing.T) { } parser := mustParse(Config{Out: &stdout, Exit: exit}, &args) assert.Nil(t, parser) - assert.Equal(t, -1, exitCode) + assert.Equal(t, 2, exitCode) } func TestMustParsePrintsHelp(t *testing.T) { @@ -9,13 +9,13 @@ import ( // the width of the left column const colWidth = 25 -// Fail prints usage information to stderr and exits with non-zero status +// Fail prints usage information to p.Config.Out and exits with status code 2. func (p *Parser) Fail(msg string) { p.FailSubcommand(msg) } -// FailSubcommand prints usage information for a specified subcommand to stderr, -// then exits with non-zero status. To write usage information for a top-level +// FailSubcommand prints usage information for a specified subcommand to p.Config.Out, +// then exits with status code 2. To write usage information for a top-level // subcommand, provide just the name of that subcommand. To write usage // information for a subcommand that is nested under another subcommand, provide // a sequence of subcommand names starting with the top-level subcommand and so @@ -27,7 +27,7 @@ func (p *Parser) FailSubcommand(msg string, subcommand ...string) error { } fmt.Fprintln(p.config.Out, "error:", msg) - p.config.Exit(-1) + p.config.Exit(2) return nil } diff --git a/usage_test.go b/usage_test.go index b13ecbc..a958abb 100644 --- a/usage_test.go +++ b/usage_test.go @@ -932,7 +932,7 @@ error: something went wrong p.Fail("something went wrong") assert.Equal(t, expectedStdout[1:], stdout.String()) - assert.Equal(t, -1, exitCode) + assert.Equal(t, 2, exitCode) } func TestFailSubcommand(t *testing.T) { @@ -955,7 +955,7 @@ error: something went wrong require.NoError(t, err) assert.Equal(t, expectedStdout[1:], stdout.String()) - assert.Equal(t, -1, exitCode) + assert.Equal(t, 2, exitCode) } type lengthOf struct { |