JSON diff and patch
jd
is a commandline utility and Go library for diffing and patching JSON values.
Try it out
Command line usage
Download latest release or go get github.com/josephburnett/jd
Diff and patch JSON files.
Prints the diff of FILE1 and FILE2 to STDOUT.
When FILE2 is omitted the second input is read from STDIN.
When patching (-p) FILE1 is a diff.
Options:
-p Apply patch FILE1 to FILE2 or STDIN.
-o=FILE3 Write to FILE3 instead of STDOUT.
-set Treat arrays as sets.
-mset Treat arrays as multisets (bags).
-setkeys Keys to identify set objects
-yaml Read and write YAML instead of JSON.
-port=N Serve web UI on port N
Examples:
jd a.json b.json
cat b.json | jd a.json
jd -o patch a.json b.json; jd patch a.json
jd -set a.json b.json
Library usage
go get github.com/josephburnett/jd
import (
"fmt"
jd "github.com/josephburnett/jd/lib"
)
func ExampleJsonNode_Diff() {
a, _ := jd.ReadJsonString(`{"foo":"bar"}`)
b, _ := jd.ReadJsonString(`{"foo":"baz"}`)
fmt.Print(a.Diff(b).Render())
// Output:
// @ ["foo"]
// - "bar"
// + "baz"
}
func ExampleJsonNode_Patch() {
a, _ := jd.ReadJsonString(`["foo"]`)
diff, _ := jd.ReadDiffString(`` +
`@ [1]` + "\n" +
`+ "bar"` + "\n")
b, _ := a.Patch(diff)
fmt.Print(b.Json())
// Output:
// ["foo","bar"]
}
Diff language
- A diff is zero or more sections
- Sections start with a
@
header and the path to a node - A path is a JSON list of zero or more elements accessing collections
- A JSON number element (e.g.
0
) accesses an array - A JSON string element (e.g.
"foo"
) accesses an object - An empty JSON object element (
{}
) accesses an array as a set or multiset - After the path is one or more removals or additions, removals first
- Removals start with
-
and then the JSON value to be removed - Additions start with
+
and then the JSON value to added
EBNF
Diff ::= ( '@' '[' ( 'JSON String' | 'JSON Number' | 'Empty JSON Object' )* ']' '\n' ( ( '-' 'JSON Value' '\n' )+ | '+' 'JSON Value' '\n' ) ( '+' 'JSON Value' '\n' )* )*
Examples
@ ["a"]
- 1
+ 2
@ [2]
+ {"foo":"bar"}
@ ["Movies",67,"Title"]
- "Dr. Strangelove"
+ "Dr. Evil Love"
@ ["Movies",67,"Actors","Dr. Strangelove"]
- "Peter Sellers"
+ "Mike Myers"
@ ["Movies",102]
+ {"Title":"Austin Powers","Actors":{"Austin Powers":"Mike Myers"}}
@ ["Movies",67,"Tags",{}]
- "Romance"
+ "Action"
+ "Comedy"