xref: /aosp_15_r20/external/bcc/examples/tracing/hello_fields.py (revision 387f9dfdfa2baef462e92476d413c7bc2470293e) 
1#!/usr/bin/python
2#
3# This is a Hello World example that formats output as fields.
4
5from bcc import BPF
6from bcc.utils import printb
7
8# define BPF program
9prog = """
10int hello(void *ctx) {
11    bpf_trace_printk("Hello, World!\\n");
12    return 0;
13}
14"""
15
16# load BPF program
17b = BPF(text=prog)
18b.attach_kprobe(event=b.get_syscall_fnname("clone"), fn_name="hello")
19
20# header
21print("%-18s %-16s %-6s %s" % ("TIME(s)", "COMM", "PID", "MESSAGE"))
22
23# format output
24while 1:
25    try:
26        (task, pid, cpu, flags, ts, msg) = b.trace_fields()
27    except ValueError:
28        continue
29    except KeyboardInterrupt:
30        exit()
31    printb(b"%-18.9f %-16s %-6d %s" % (ts, task, pid, msg))
32