Added functions.json

* Uses safer method to get JSON data from a command
* Replaced nearly all uses of json.loads with new get_json_from_command()
* Fixes issue #100

.bin/Scripts/functions/data.py

@@ -78,8 +78,7 @@ def find_core_storage_volumes(device_path=None):
     '--output', 'NAME,PARTTYPE']
   if device_path:
     cmd.append(device_path)
-  result = run_program(cmd)
-  json_data = json.loads(result.stdout.decode())
+  json_data = get_json_from_command(cmd)
   devs = json_data.get('blockdevices', [])
   devs = [d for d in devs if d.get('parttype', '') == corestorage_uuid]
   if devs:
@@ -159,8 +158,7 @@ def get_mounted_volumes():
       'devtmpfs,hugetlbfs,mqueue,proc,pstore,securityfs,sysfs,tmpfs'
       ),
     '-o', 'SOURCE,TARGET,FSTYPE,LABEL,SIZE,AVAIL,USED']
-  result = run_program(cmd)
-  json_data = json.loads(result.stdout.decode())
+  json_data = get_json_from_command(cmd)
   mounted_volumes = []
   for item in json_data.get('filesystems', []):
     mounted_volumes.append(item)
@@ -185,8 +183,7 @@ def mount_volumes(
     find_core_storage_volumes(device_path)
 
   # Get list of block devices
-  result = run_program(cmd)
-  json_data = json.loads(result.stdout.decode())
+  json_data = get_json_from_command(cmd)
   devs = json_data.get('blockdevices', [])
 
   # Get list of volumes

.bin/Scripts/functions/ddrescue.py

@@ -1,6 +1,5 @@
 # Wizard Kit: Functions - ddrescue-tui
 
-import json
 import pathlib
 import psutil
 import re
@@ -11,6 +10,7 @@ import time
 from collections import OrderedDict
 from functions.data import *
 from functions.hw_diags import *
+from functions.json import *
 from functions.tmux import *
 from operator import itemgetter
 from settings.ddrescue import *
@@ -346,15 +346,14 @@ class RecoveryState():
     map_allowed_fstypes = RECOMMENDED_FSTYPES.copy()
     map_allowed_fstypes.extend(['cifs', 'ext2', 'vfat'])
     map_allowed_fstypes.sort()
-    json_data = {}
+    json_data = get_json_from_command(cmd)
 
-    # Avoid saving map to non-persistent filesystem
-    try:
-      result = run_program(cmd)
-      json_data = json.loads(result.stdout.decode())
-    except Exception:
+    # Abort if json_data is empty
+    if not json_data:
       print_error('ERROR: Failed to verify map path')
       raise GenericAbort()
+
+    # Avoid saving map to non-persistent filesystem
     fstype = json_data.get(
       'filesystems', [{}])[0].get(
       'fstype', 'unknown')
@@ -547,21 +546,11 @@ def fix_tmux_panes(state, forced=False):
 
 def get_device_details(dev_path):
   """Get device details via lsblk, returns JSON dict."""
-  try:
-    cmd = (
-      'lsblk',
-      '--json',
-      '--output-all',
-      '--paths',
-      dev_path)
-    result = run_program(cmd)
-  except CalledProcessError:
-    # Return empty dict and let calling section deal with the issue
-    return {}
+  cmd = ['lsblk', '--json', '--output-all', '--paths', dev_path]
+  json_data = get_json_from_command(cmd)
 
-  json_data = json.loads(result.stdout.decode())
   # Just return the first device (there should only be one)
-  return json_data['blockdevices'][0]
+  return json_data.get('blockdevices', [{}])[0]
 
 
 def get_device_report(dev_path):
@@ -594,17 +583,19 @@ def get_device_report(dev_path):
 
 def get_dir_details(dir_path):
   """Get dir details via findmnt, returns JSON dict."""
-  try:
-    result = run_program([
-      'findmnt', '-J',
-      '-o', 'SOURCE,TARGET,FSTYPE,OPTIONS,SIZE,AVAIL,USED',
-      '-T', dir_path])
-    json_data = json.loads(result.stdout.decode())
-  except Exception:
+  cmd = [
+    'findmnt', '-J',
+    '-o', 'SOURCE,TARGET,FSTYPE,OPTIONS,SIZE,AVAIL,USED',
+    '-T', dir_path,
+    ]
+  json_data = get_json_from_command(cmd)
+
+  # Raise exception if json_data is empty
+  if not json_data:
     raise GenericError(
-      'Failed to get directory details for "{}".'.format(self.path))
-  else:
-    return json_data['filesystems'][0]
+      'Failed to get directory details for "{}".'.format(dir_path))
+
+  return json_data.get('filesystems', [{}])[0]
 
 
 def get_dir_report(dir_path):
@@ -1210,14 +1201,8 @@ def select_path(skip_device=None):
 
 def select_device(description='device', skip_device=None):
   """Select device via a menu, returns DevObj."""
-  cmd = (
-    'lsblk',
-    '--json',
-    '--nodeps',
-    '--output-all',
-    '--paths')
-  result = run_program(cmd)
-  json_data = json.loads(result.stdout.decode())
+  cmd = ['lsblk', '--json', '--nodeps', '--output-all', '--paths']
+  json_data = get_json_from_command(cmd)
   skip_names = []
   if skip_device:
     skip_names.append(skip_device.path)
@@ -1226,7 +1211,7 @@ def select_device(description='device', skip_device=None):
 
   # Build menu
   dev_options = []
-  for dev in json_data['blockdevices']:
+  for dev in json_data.get('blockdevices', []):
     # Disable dev if in skip_names
     disabled = dev['name'] in skip_names or dev['pkname'] in skip_names
 

.bin/Scripts/functions/hw_diags.py

@@ -1,10 +1,10 @@
 # Wizard Kit: Functions - HW Diagnostics
 
-import json
 import re
 import time
 
 from collections import OrderedDict
+from functions.json import *
 from functions.sensors import *
 from functions.threading import *
 from functions.tmux import *
@@ -38,15 +38,10 @@ class CpuObj():
   def get_details(self):
     """Get CPU details from lscpu."""
     cmd = ['lscpu', '--json']
-    try:
-      result = run_program(cmd, check=False)
-      json_data = json.loads(result.stdout.decode())
-    except Exception:
-      # Ignore and leave self.lscpu empty
-      return
-    for line in json_data.get('lscpu', []):
-      _field = line.get('field', None).replace(':', '')
-      _data = line.get('data', None)
+    json_data = get_json_from_command(cmd)
+    for line in json_data.get('lscpu', [{}]):
+      _field = line.get('field', '').replace(':', '')
+      _data = line.get('data', '')
       if not _field and not _data:
         # Skip
         print_warning(_field, _data)
@@ -311,13 +306,8 @@ class DiskObj():
   def get_details(self):
     """Get data from lsblk."""
     cmd = ['lsblk', '--json', '--output-all', '--paths', self.path]
-    try:
-      result = run_program(cmd, check=False)
-      json_data = json.loads(result.stdout.decode())
-      self.lsblk = json_data['blockdevices'][0]
-    except Exception:
-      # Leave self.lsblk empty
-      pass
+    json_data = get_json_from_command(cmd)
+    self.lsblk = json_data.get('blockdevices', [{}])[0]
 
     # Set necessary details
     self.lsblk['model'] = self.lsblk.get('model', 'Unknown Model')
@@ -358,12 +348,7 @@ class DiskObj():
   def get_smart_details(self):
     """Get data from smartctl."""
     cmd = ['sudo', 'smartctl', '--all', '--json', self.path]
-    try:
-      result = run_program(cmd, check=False)
-      self.smartctl = json.loads(result.stdout.decode())
-    except Exception:
-      # Leave self.smartctl empty
-      pass
+    self.smartctl = get_json_from_command(cmd)
 
     # Check for attributes
     if KEY_NVME in self.smartctl:
@@ -518,9 +503,8 @@ class State():
 
     # Add block devices
     cmd = ['lsblk', '--json', '--nodeps', '--paths']
-    result = run_program(cmd, check=False)
-    json_data = json.loads(result.stdout.decode())
-    for disk in json_data['blockdevices']:
+    json_data = get_json_from_command(cmd)
+    for disk in json_data.get('blockdevices', []):
       skip_disk = False
       disk_obj = DiskObj(disk['name'])
 

.bin/Scripts/functions/json.py

@@ -0,0 +1,32 @@
+# Wizard Kit: Functions - JSON
+
+import json
+
+from functions.common import *
+
+def get_json_from_command(cmd, ignore_errors=True):
+  """Capture JSON content from cmd output, returns dict.
+  
+  If the data can't be decoded then either an exception is raised
+  or an empty dict is returned depending on ignore_errors.
+  """
+  errors = 'strict'
+  json_data = {}
+
+  if ignore_errors:
+    errors = 'ignore'
+
+  try:
+    result = run_program(cmd, encoding='utf-8', errors=errors)
+    json_data = json.loads(result.stdout)
+  except (subprocess.CalledProcessError, json.decoder.JSONDecodeError):
+    if not ignore_errors:
+      raise
+  
+  return json_data
+
+
+if __name__ == '__main__':
+  print("This file is not meant to be called directly.")
+
+# vim: sts=2 sw=2 ts=2

.bin/Scripts/functions/sensors.py

@@ -105,7 +105,7 @@ def get_raw_sensor_data():
   # Get raw data
   try:
     result = run_program(cmd)
-    result = result.stdout.decode().splitlines()
+    result = result.stdout.decode('utf-8', errors='ignore').splitlines()
   except subprocess.CalledProcessError:
     # Assuming no sensors available, set to empty list
     result = []