old_contents: #!/usr/bin/python
  #
  # mysqld_query    Trace MySQL server queries. Example of USDT tracing.
  #                 For Linux, uses BCC, BPF. Embedded C.
  #
  # USAGE: mysqld_query PID
  #
  # This uses USDT probes, and needs a MySQL server with -DENABLE_DTRACE=1.
  #
  # Copyright 2016 Netflix, Inc.
  # Licensed under the Apache License, Version 2.0 (the "License")
  
  from __future__ import print_function
  from bcc import BPF, USDT
  from bcc.utils import printb
  import sys
  
  if len(sys.argv) < 2:
      print("USAGE: mysqld_latency PID")
      exit()
  pid = sys.argv[1]
  debug = 0
  
  # load BPF program
  bpf_text = """
  #include <uapi/linux/ptrace.h>
  int do_trace(struct pt_regs *ctx) {
      uint64_t addr;
      char query[128];
      /*
       * Read the first argument from the query-start probe, which is the query.
       * The format of this probe is:
       * query-start(query, connectionid, database, user, host)
       * see: https://dev.mysql.com/doc/refman/5.7/en/dba-dtrace-ref-query.html
       */
      bpf_usdt_readarg(1, ctx, &addr);
      bpf_trace_printk("%s\\n", addr);
      return 0;
  };
  """
  
  # enable USDT probe from given PID
  u = USDT(pid=int(pid))
  u.enable_probe(probe="query__start", fn_name="do_trace")
  if debug:
      print(u.get_text())
      print(bpf_text)
  
  # initialize BPF
  b = BPF(text=bpf_text, usdt_contexts=[u])
  
  # header
  print("%-18s %-16s %-6s %s" % ("TIME(s)", "COMM", "PID", "QUERY"))
  
  # format output
  while 1:
      try:
          (task, pid, cpu, flags, ts, msg) = b.trace_fields()
      except ValueError:
          print("value error")
          continue
      except KeyboardInterrupt:
          exit()
      printb(b"%-18.9f %-16s %-6d %s" % (ts, task, pid, msg))
  
new_contents: #!/usr/bin/python
  #
  # mysqld_query    Trace MySQL server queries. Example of USDT tracing.
  #                 For Linux, uses BCC, BPF. Embedded C.
  #
  # USAGE: mysqld_query PID
  #
  # This uses USDT probes, and needs a MySQL server with -DENABLE_DTRACE=1.
  #
  # Copyright 2016 Netflix, Inc.
  # Licensed under the Apache License, Version 2.0 (the "License")
  
  from __future__ import print_function
  from bcc import BPF, USDT
  from bcc.utils import printb
  import sys
  
  if len(sys.argv) < 2:
      print("USAGE: mysqld_latency PID")
      exit()
  pid = sys.argv[1]
  debug = 0
  
  # load BPF program
  bpf_text = """
  #include <uapi/linux/ptrace.h>
  int do_trace(struct pt_regs *ctx) {
      uint64_t addr;
      char query[128];
      /*
       * Read the first argument from the query-start probe, which is the query.
       * The format of this probe is:
       * query-start(query, connectionid, database, user, host)
       * see: https://dev.mysql.com/doc/refman/5.7/en/dba-dtrace-ref-query.html
       */
      bpf_usdt_readarg(1, ctx, &addr);
      bpf_probe_read(&query, sizeof(query), (void *)addr);
      bpf_trace_printk("%s\\n", query);
      return 0;
  };
  """
  
  # enable USDT probe from given PID
  u = USDT(pid=int(pid))
  u.enable_probe(probe="query__start", fn_name="do_trace")
  if debug:
      print(u.get_text())
      print(bpf_text)
  
  # initialize BPF
  b = BPF(text=bpf_text, usdt_contexts=[u])
  
  # header
  print("%-18s %-16s %-6s %s" % ("TIME(s)", "COMM", "PID", "QUERY"))
  
  # format output
  while 1:
      try:
          (task, pid, cpu, flags, ts, msg) = b.trace_fields()
      except ValueError:
          print("value error")
          continue
      except KeyboardInterrupt:
          exit()
      printb(b"%-18.9f %-16s %-6d %s" % (ts, task, pid, msg))
  
subject: Update mysqld_query.py