https://github.com/mohd-akram/jawk

Awk for JSON.
https://github.com/mohd-akram/jawk

awk json shell unix

Last synced: 26 days ago
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Awk for JSON.

• Host: GitHub
• URL: https://github.com/mohd-akram/jawk
• Owner: mohd-akram
• License: mit
• Created: 2020-08-09T22:06:56.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2024-01-16T09:39:50.000Z (10 months ago)
• Last Synced: 2024-08-07T18:44:27.750Z (3 months ago)
• Topics: awk, json, shell, unix
• Language: Shell
• Homepage:
• Size: 54.7 KB
• Stars: 42
• Watchers: 3
• Forks: 2
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# jawk

awk for JSON.

## Install

Run `make install` as root to install `jawk` to `/usr/local/bin`.

or

Copy the `jawk` file to somewhere in your `PATH`.

## Examples

```shell

$ echo '{"age":10}' | jawk '{print _["age"]}'

10

$ echo '{"person":{"name":"Jason"}}' | jawk '{print _["person","name"]}'

Jason

$ echo '[4,2,0]' | jawk '{while (++i <= _["length"]) print _[i]}'

4

2

0

$ echo '[{"x":6},{"x":7}]' | jawk '{while (++i <= _["length"]) print _[i,"x"]}'

6

7

$ printf '{"x":6}\n{"x":7}\n' | jawk '{print _["x"]}'

6

7

$ echo '{"name":{"first":"Jason"},"age":25}' | jawk '{

	keys(o); for (k in o) print k, _[o[k],JSON]

}'

name {"first":"Jason"}

age 25

$ echo '{"name":"Jason"}' | jawk '{print _["name",JSON]}'

"Jason"

# Try it with real data!

curl -Ls https://api.github.com/repos/onetrueawk/awk |

jawk '{print "id:", _["id"], "owner.id:", _["owner","id"]}'

curl -Ls https://api.github.com/repos/onetrueawk/awk/commits |

jawk '{

	while (++i <= _["length"]) {

		sha = _[i,"sha"]

		message = _[i,"commit","message"]

		l = index(message, "\n")

		print sha, substr(message, 1, l ? l - 1 : 50)

	}

}'

curl -Ls https://api.github.com/repos/onetrueawk/awk/commits |

jawk '{while (++i <= _["length"]) printf("{\"sha\":%s}\n",_[i,"sha",JSON])}'

```

## Details

jawk makes available each JSON object using the `_` variable. `jawk` programs

are `awk` programs, and all `awk` features and functions are available. Nested

fields can be accessed using standard awk indexing (eg. `_["foo","bar"]`).

Some conversions are done: the value `true` is converted to 1, `false` is

converted to 0 and `null` is converted to `""`. Arrays are 1-indexed.

## Properties

### _[p]

Return the value of the object at path `p` if it's a primitive, or `p` if it's

an object or array. If the root object is a primitive, `_[0]` returns its

value.

### _[[p,]"length"]

Return the length of the array at path `p`, or the root array if `p` is

omitted.

### _[[p,]JSON]

Return the JSON form of the object at path `p`, or the root object if `p` is

omitted.

### _[[p,]TYPE]

Return the type of the object at path `p`, or the root object if `p` is

omitted. The result will be one of `boolean`, `null`, `array`, `object`,

`string` or `number`.

## Functions

### keys(a[, o])

Populate the array `a` with the keys of the object at path `o` such that `a[k]

= p` where `k` is the key and `p` is its full path. The path can then be passed

to `_` to retrieve its value. If `o` isn't provided, `a` is populated with the

keys and paths of the root object. Returns the number of keys.

## Development

Make changes to `src/jawk.sh` and run `make` to produce `jawk`. Run `make -B

test` to test changes.