focal (3) mongoc_debugging.3.gz

NAME

       mongoc_debugging - Aids for Debugging

GDB

       This  repository  contains  a  .gdbinit  file  that  contains  helper  functions to aid debugging of data
       structures. GDB will load this file automatically if you have added  the  directory  which  contains  the
       .gdbinit file to GDB's auto-load safe-path, and you start GDB from the directory which holds the .gdbinit
       file.

       You can see the safe-path with show auto-load safe-path on a GDB prompt. You can configure it by  setting
       it in ~/.gdbinit with:

          add-auto-load-safe-path /path/to/mongo-c-driver

       If  you  haven't  added the path to your auto-load safe-path, or start GDB in another directory, load the
       file with:

          source path/to/mongo-c-driver/.gdbinit

       The .gdbinit file defines the printbson function, which shows the contents of a bson_t  *  variable.   If
       you have a local bson_t, then you must prefix the variable with a &.

       An example GDB session looks like:

          (gdb) printbson bson
          ALLOC [0x555556cd7310 + 0] (len=475)
          {
              'bool' : true,
              'int32' : NumberInt("42"),
              'int64' : NumberLong("3000000042"),
              'string' : "Stŕìñg",
              'objectId' : ObjectID("5A1442F3122D331C3C6757E1"),
              'utcDateTime' : UTCDateTime(1511277299031),
              'arrayOfInts' : [
                  '0' : NumberInt("1"),
                  '1' : NumberInt("2")
              ],
              'embeddedDocument' : {
                  'arrayOfStrings' : [
                      '0' : "one",
                      '1' : "two"
                  ],
                  'double' : 2.718280,
                  'notherDoc' : {
                      'true' : NumberInt("1"),
                      'false' : false
                  }
              },
              'binary' : Binary("02", "3031343532333637"),
              'regex' : Regex("@[a-z]+@", "im"),
              'null' : null,
              'js' : JavaScript("print foo"),
              'jsws' : JavaScript("print foo") with scope: {
                  'f' : NumberInt("42"),
                  'a' : [
                      '0' : 3.141593,
                      '1' : 2.718282
                  ]
              },
              'timestamp' : Timestamp(4294967295, 4294967295),
              'double' : 3.141593
          }

LLDB

       This repository also includes a script that customizes LLDB's standard print command to print a bson_t or
       bson_t * as JSON:

          (lldb) print b
          (bson_t) $0 = {"x": 1, "y": 2}

       The custom bson command provides more options:

          (lldb) bson --verbose b
          len=19
          flags=INLINE|STATIC
          {
            "x": 1,
            "y": 2
          }
          (lldb) bson --raw b
          '\x13\x00\x00\x00\x10x\x00\x01\x00\x00\x00\x10y\x00\x02\x00\x00\x00\x00'

       Type help bson for a list of options.

       The script requires a build of libbson with debug  symbols,  and  an  installation  of  PyMongo.  Install
       PyMongo with:

          python -m pip install pymongo

       If you see "No module named pip" then you must install pip, then run the previous command again.

       Create a file ~/.lldbinit containing:

          command script import /path/to/mongo-c-driver/lldb_bson.py

       If  you see "bson command installed by lldb_bson" at the beginning of your LLDB session, you've installed
       the script correctly.

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2017-present, MongoDB, Inc