ctags-json-output - JSON based ctags output

NAME SYNOPSIS DESCRIPTION FORMAT DATA TYPE USED IN A FIELD VERSIONS Change since "0.0" SEE ALSO

NAME

ctags-json-output − JSON based ctags output

Universal Ctags supports JSON <https://www.json.org/>
(strictly speaking JSON Lines <https://jsonlines.org/> ) output format if the ctags executable is built with libjansson. JSON output goes to standard output by default.

FORMAT

Each JSON line represents a tag.

$ ctags −−extras=+p −−output−format=json −−fields=−s input.py
{"_type": "ptag", "name": "JSON_OUTPUT_VERSION", "path": "1.0", "pattern": "in development"}
{"_type": "ptag", "name": "TAG_FILE_SORTED", "path": "1", "pattern": "0=unsorted, 1=sorted, 2=foldcase"}
...
{"_type": "tag", "name": "Klass", "path": "/tmp/input.py", "pattern": "/ˆclass Klass:$/", "language": "Python", "kind": "class"}
{"_type": "tag", "name": "method", "path": "/tmp/input.py", "pattern": "/ˆ def method(self):$/", "language": "Python", "kind": "member", "scope": "Klass", "scopeKind": "class"}
...

A key not starting with _ is mapped to a field of ctags. "−−output−format=json −−list−fields" options list the fields.

A key starting with _ represents meta information of the JSON line. Currently only _type key is used. If the value for the key is tag, the JSON line represents a regular tag. If the value is ptag, the line represents a pseudo−tag.

The output format can be changed in the future. JSON_OUTPUT_VERSION pseudo−tag provides a change client−tools to handle the changes. Current version is "1.0". A client−tool can extract the version with path key from the pseudo−tag.

The JSON output format is newly designed and has no limitation found in the default tags file format.

	•		The values for kind key are represented in long−name flags. No one−letter is here.
	•		Scope names and scope kinds have distinguished keys: scope and scopeKind. They are combined in the default tags file format.

DATA TYPE USED IN A FIELD

Values for the most of all keys are represented in JSON string type. However, some of them are represented in string, integer, and/or boolean type.

"−−output−format=json −−list−fields" options show What kind of data type used in a field of JSON.

$ ctags −−output−format=json −−list−fields
#LETTER NAME ENABLED LANGUAGE JSTYPE FIXED DESCRIPTION
F input yes NONE s−− no input file
...
P pattern yes NONE s−b no pattern
...
f file yes NONE −−b no File−restricted scoping
...
e end no NONE −i− no end lines of various items
...

JSTYPE column shows the data types.

	's'		string
	'i'		integer
	'b'		boolean (true or false)

For an example, the value for pattern field of ctags takes a string or a boolean value.

VERSIONS

Change since "0.0"

•

New key kindName for TAG_ROLE_DESCRIPTION pseudo tag

kindName is added to store the name of the kind in TAG_ROLE_DESCRIPTION pseudo tags.

In 0.0, a "TAG_ROLE_DESCRIPTION" pseudo tag was printed like:

{"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION",
"parserName": "LANG!KIND", }

In 1.0, it is printed like:

{"_type": "ptag", "name": "TAG_ROLE_DESCRIPTION",
"parserName": "LANG",
"kindName": "KIND", }