Prints a json string in a pretty formatted output on stdout

json_prettifier.py

#!/usr/bin/env python3
"""
Prints a json string in a pretty formatted output on stdout.

Example call:

echo "{\"a\":100, \"b\": [1,2,3]}"  | ./json_prettifier.py

will print:
{
    "a": 100,
    "b": [
        1,
        2,
        3
    ]
}
"""
import json
import sys


obj = ""
for l in sys.stdin:
    obj += l

jobj = obj.strip()

if jobj == "":
    sys.exit(0)

try:
    j = json.loads(jobj)
    print(json.dumps(j, indent=4, sort_keys=True))

except Exception as e:
    print('error: ' + str(e) + str(jobj), file=sys.stderr)