opensnoop.bt

#!/usr/bin/env bpftrace
/*
 * opensnoop	Trace open() syscalls.
 *		For Linux, uses bpftrace and eBPF.
 *
 * Also a basic example of bpftrace.
 *
 * USAGE: opensnoop.bt
 *
 * This is a bpftrace version of the bcc tool of the same name.
 *
 * Copyright 2018 Netflix, Inc.
 * Licensed under the Apache License, Version 2.0 (the "License")
 *
 * 08-Sep-2018	Brendan Gregg	Created this.
 */

BEGIN
{
	printf("Tracing open syscalls... Hit Ctrl-C to end.\n");
	printf("%-6s %-16s %4s %3s %s\n", "PID", "COMM", "FD", "ERR", "PATH");
}

tracepoint:syscalls:sys_enter_open,
tracepoint:syscalls:sys_enter_openat
{
	@filename[tid] = args->filename;
}

tracepoint:syscalls:sys_exit_open,
tracepoint:syscalls:sys_exit_openat
/@filename[tid]/
{
	$ret = args->ret;
	$fd = $ret > 0 ? $ret : -1;
	$errno = $ret > 0 ? 0 : - $ret;

	printf("%-6d %-16s %4d %3d %s\n", pid, comm, $fd, $errno,
	    str(@filename[tid]));
	delete(@filename[tid]);
}

END
{
	clear(@filename);
}