forked from jmespath/jp
-
Notifications
You must be signed in to change notification settings - Fork 0
/
jp.go
123 lines (114 loc) · 2.9 KB
/
jp.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
"github.com/jmespath/jp/Godeps/_workspace/src/github.com/codegangsta/cli"
"github.com/jmespath/jp/Godeps/_workspace/src/github.com/jmespath/go-jmespath"
)
const version = "0.1.3"
func main() {
app := cli.NewApp()
app.Name = "jp"
app.Version = version
app.Usage = "jp [<options>] <expression>"
app.Author = ""
app.Email = ""
app.Flags = []cli.Flag{
cli.StringFlag{
Name: "filename, f",
Usage: "Read input JSON from a file instead of stdin.",
},
cli.StringFlag{
Name: "expr-file, e",
Usage: "Read JMESPath expression from the specified file.",
},
cli.BoolFlag{
Name: "unquoted, u",
Usage: "If the final result is a string, it will be printed without quotes.",
EnvVar: "JP_UNQUOTED",
},
cli.BoolFlag{
Name: "ast",
Usage: "Only print the AST of the parsed expression. Do not rely on this output, only useful for debugging purposes.",
},
}
app.Action = runMainAndExit
app.Run(os.Args)
}
func runMainAndExit(c *cli.Context) {
os.Exit(runMain(c))
}
func errMsg(msg string, a ...interface{}) int {
fmt.Fprintf(os.Stderr, msg, a...)
fmt.Fprintln(os.Stderr)
return 1
}
func runMain(c *cli.Context) int {
var expression string
if c.String("expr-file") != "" {
byteExpr, err := ioutil.ReadFile(c.String("expr-file"))
expression = string(byteExpr)
if err != nil {
return errMsg("Error opening expression file: %s", err)
}
} else {
if len(c.Args()) == 0 {
return errMsg("Must provide at least one argument.")
}
expression = c.Args()[0]
}
if c.Bool("ast") {
parser := jmespath.NewParser()
parsed, err := parser.Parse(expression)
if err != nil {
if syntaxError, ok := err.(jmespath.SyntaxError); ok {
return errMsg("%s\n%s\n",
syntaxError,
syntaxError.HighlightLocation())
}
return errMsg("%s", err)
}
fmt.Println("")
fmt.Printf("%s\n", parsed)
return 0
}
var input interface{}
var jsonParser *json.Decoder
if c.String("filename") != "" {
f, err := os.Open(c.String("filename"))
if err != nil {
return errMsg("Error opening input file: %s", err)
}
jsonParser = json.NewDecoder(f)
} else {
jsonParser = json.NewDecoder(os.Stdin)
}
if err := jsonParser.Decode(&input); err != nil {
errMsg("Error parsing input json: %s\n", err)
return 2
}
result, err := jmespath.Search(expression, input)
if err != nil {
if syntaxError, ok := err.(jmespath.SyntaxError); ok {
return errMsg("%s\n%s\n",
syntaxError,
syntaxError.HighlightLocation())
}
return errMsg("Error evaluating JMESPath expression: %s", err)
}
converted, isString := result.(string)
if c.Bool("unquoted") && isString {
os.Stdout.WriteString(converted)
} else {
toJSON, err := json.MarshalIndent(result, "", " ")
if err != nil {
errMsg("Error marshalling result to JSON: %s\n", err)
return 3
}
os.Stdout.Write(toJSON)
}
os.Stdout.WriteString("\n")
return 0
}