A virtual jailed shell environment for Go apps backed by an io/fs#FS.
feat(command): port dirname from just-bash
Strip the last component from each NAME. Mirrors GNU dirname
semantics as implemented by just-bash: trailing slashes are
collapsed before splitting, a name with no slash yields ".",
and a name whose only slashes are leading yields "/".
Signed-off-by: Xe Iaso <me@xeiaso.net>
Assisted-by: Claude Opus 4.7 via Claude Code
+218
+82
command/internal/dirname/dirname.go
+82
command/internal/dirname/dirname.go
···
1
+
package dirname
2
+
3
+
import (
4
+
"context"
5
+
"errors"
6
+
"fmt"
7
+
"io"
8
+
"strings"
9
+
10
+
"github.com/pborman/getopt/v2"
11
+
"mvdan.cc/sh/v3/interp"
12
+
"tangled.org/xeiaso.net/kefka/command"
13
+
)
14
+
15
+
type Impl struct{}
16
+
17
+
func (Impl) Exec(ctx context.Context, ec *command.ExecContext, args []string) error {
18
+
if ec == nil {
19
+
return errors.New("dirname: nil ExecContext")
20
+
}
21
+
22
+
stdout := ec.Stdout
23
+
if stdout == nil {
24
+
stdout = io.Discard
25
+
}
26
+
stderr := ec.Stderr
27
+
if stderr == nil {
28
+
stderr = io.Discard
29
+
}
30
+
31
+
set := getopt.New()
32
+
set.SetProgram("dirname")
33
+
set.SetParameters("NAME...")
34
+
35
+
usage := func() {
36
+
fmt.Fprint(stderr, "Usage: dirname [OPTION] NAME...\n")
37
+
fmt.Fprint(stderr, "Strip last component from file name.\n\n")
38
+
fmt.Fprint(stderr, " --help display this help and exit\n")
39
+
}
40
+
set.SetUsage(usage)
41
+
42
+
help := set.BoolLong("help", 0, "display this help and exit")
43
+
44
+
if err := set.Getopt(append([]string{"dirname"}, args...), nil); err != nil {
45
+
fmt.Fprintf(stderr, "dirname: %s\n", err)
46
+
usage()
47
+
return interp.ExitStatus(1)
48
+
}
49
+
50
+
if *help {
51
+
usage()
52
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return nil
53
+
}
54
+
55
+
names := set.Args()
56
+
if len(names) == 0 {
57
+
fmt.Fprint(stderr, "dirname: missing operand\n")
58
+
return interp.ExitStatus(1)
59
+
}
60
+
61
+
results := make([]string, 0, len(names))
62
+
for _, name := range names {
63
+
results = append(results, dirnameOf(name))
64
+
}
65
+
66
+
io.WriteString(stdout, strings.Join(results, "\n"))
67
+
io.WriteString(stdout, "\n")
68
+
return nil
69
+
}
70
+
71
+
func dirnameOf(name string) string {
72
+
clean := strings.TrimRight(name, "/")
73
+
idx := strings.LastIndex(clean, "/")
74
+
switch idx {
75
+
case -1:
76
+
return "."
77
+
case 0:
78
+
return "/"
79
+
default:
80
+
return clean[:idx]
81
+
}
82
+
}
+134
command/internal/dirname/dirname_test.go
+134
command/internal/dirname/dirname_test.go
···
1
+
package dirname
2
+
3
+
import (
4
+
"bytes"
5
+
"context"
6
+
"strings"
7
+
"testing"
8
+
9
+
"tangled.org/xeiaso.net/kefka/command"
10
+
)
11
+
12
+
func run(t *testing.T, args []string) (string, string, error) {
13
+
t.Helper()
14
+
var stdout, stderr bytes.Buffer
15
+
ec := &command.ExecContext{
16
+
Stdout: &stdout,
17
+
Stderr: &stderr,
18
+
Dir: ".",
19
+
}
20
+
err := Impl{}.Exec(context.Background(), ec, args)
21
+
return stdout.String(), stderr.String(), err
22
+
}
23
+
24
+
func TestDirname(t *testing.T) {
25
+
tests := []struct {
26
+
name string
27
+
args []string
28
+
wantStdout string
29
+
wantErrSub string
30
+
wantErr bool
31
+
}{
32
+
{
33
+
name: "single path",
34
+
args: []string{"/usr/local/bin/sh"},
35
+
wantStdout: "/usr/local/bin\n",
36
+
},
37
+
{
38
+
name: "no slash",
39
+
args: []string{"foo"},
40
+
wantStdout: ".\n",
41
+
},
42
+
{
43
+
name: "trailing slash",
44
+
args: []string{"/usr/local/bin/"},
45
+
wantStdout: "/usr/local\n",
46
+
},
47
+
{
48
+
name: "multiple trailing slashes",
49
+
args: []string{"foo/bar///"},
50
+
wantStdout: "foo\n",
51
+
},
52
+
{
53
+
name: "root only",
54
+
args: []string{"/"},
55
+
wantStdout: ".\n",
56
+
},
57
+
{
58
+
name: "single component under root",
59
+
args: []string{"/foo"},
60
+
wantStdout: "/\n",
61
+
},
62
+
{
63
+
name: "single component under root with trailing slash",
64
+
args: []string{"/foo/"},
65
+
wantStdout: "/\n",
66
+
},
67
+
{
68
+
name: "empty string",
69
+
args: []string{""},
70
+
wantStdout: ".\n",
71
+
},
72
+
{
73
+
name: "relative two-component path",
74
+
args: []string{"foo/bar"},
75
+
wantStdout: "foo\n",
76
+
},
77
+
{
78
+
name: "multiple operands",
79
+
args: []string{"/a/b", "/c/d", "e"},
80
+
wantStdout: "/a\n/c\n.\n",
81
+
},
82
+
{
83
+
name: "missing operand",
84
+
args: []string{},
85
+
wantErrSub: "missing operand",
86
+
wantErr: true,
87
+
},
88
+
{
89
+
name: "unknown flag",
90
+
args: []string{"--no-such-flag", "foo"},
91
+
wantErr: true,
92
+
},
93
+
{
94
+
name: "double dash terminator",
95
+
args: []string{"--", "-weird-name"},
96
+
wantStdout: ".\n",
97
+
},
98
+
}
99
+
100
+
for _, tt := range tests {
101
+
t.Run(tt.name, func(t *testing.T) {
102
+
stdout, stderr, err := run(t, tt.args)
103
+
if tt.wantErr {
104
+
if err == nil {
105
+
t.Fatalf("expected error, got nil; stdout=%q stderr=%q", stdout, stderr)
106
+
}
107
+
} else if err != nil {
108
+
t.Fatalf("unexpected error: %v; stderr=%q", err, stderr)
109
+
}
110
+
if tt.wantStdout != "" && stdout != tt.wantStdout {
111
+
t.Errorf("stdout = %q, want %q", stdout, tt.wantStdout)
112
+
}
113
+
if tt.wantErrSub != "" && !strings.Contains(stderr, tt.wantErrSub) {
114
+
t.Errorf("stderr = %q, want substring %q", stderr, tt.wantErrSub)
115
+
}
116
+
})
117
+
}
118
+
}
119
+
120
+
func TestHelp(t *testing.T) {
121
+
stdout, stderr, err := run(t, []string{"--help"})
122
+
if err != nil {
123
+
t.Fatalf("unexpected error: %v", err)
124
+
}
125
+
if stdout != "" {
126
+
t.Errorf("expected empty stdout, got %q", stdout)
127
+
}
128
+
if !strings.Contains(stderr, "Usage: dirname [OPTION] NAME...") {
129
+
t.Errorf("usage line missing from stderr: %q", stderr)
130
+
}
131
+
if !strings.Contains(stderr, "--help") {
132
+
t.Errorf("help flag missing from help output: %q", stderr)
133
+
}
134
+
}
+2
command/registry/coreutils/coreutils.go
+2
command/registry/coreutils/coreutils.go
···
10
10
"tangled.org/xeiaso.net/kefka/command/internal/cut"
11
11
"tangled.org/xeiaso.net/kefka/command/internal/date"
12
12
"tangled.org/xeiaso.net/kefka/command/internal/diff"
13
+
"tangled.org/xeiaso.net/kefka/command/internal/dirname"
13
14
"tangled.org/xeiaso.net/kefka/command/internal/falsecmd"
14
15
"tangled.org/xeiaso.net/kefka/command/internal/hostname"
15
16
"tangled.org/xeiaso.net/kefka/command/internal/ls"
···
27
28
reg.Register("cut", cut.Impl{})
28
29
reg.Register("date", date.Impl{})
29
30
reg.Register("diff", diff.Impl{})
31
+
reg.Register("dirname", dirname.Impl{})
30
32
reg.Register("false", falsecmd.Impl{})
31
33
reg.Register("hostname", hostname.Impl{})
32
34
reg.Register("ls", ls.Impl{})