libbpf-tools: Add verbose option to solisten

Support verbose mode and set custom libbpf print callback
in solisten.

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

diff --git a/libbpf-tools/solisten.c b/libbpf-tools/solisten.c
index bf340b51f58ed6f4c75f65b41274bd128a3fd740..adaa668dfcf5689963e1dbb1f7b8a9acf7f097f7 100644 (file)
--- a/libbpf-tools/solisten.c
+++ b/libbpf-tools/solisten.c
@@ -29,6 +29,7 @@ static volatile sig_atomic_t exiting = 0;
 
 static pid_t target_pid = 0;
 static bool emit_timestamp = false;
+static bool verbose = false;
 
 const char *argp_program_version = "solisten 0.1";
 const char *argp_program_bug_address =
@@ -44,9 +45,10 @@ const char argp_program_doc[] =
 "    solisten -p 1216   # only trace PID 1216\n";
 
 static const struct argp_option opts[] = {
-       {"pid", 'p', "PID", 0, "Process ID to trace"},
-       {"timestamp", 't', NULL, 0, "Include timestamp on output"},
-       {NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help"},
+       { "pid", 'p', "PID", 0, "Process ID to trace" },
+       { "timestamp", 't', NULL, 0, "Include timestamp on output" },
+       { "verbose", 'v', NULL, 0, "Verbose debug output" },
+       { NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
        {},
 };
 
@@ -67,6 +69,9 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
        case 't':
                emit_timestamp = true;
                break;
+       case 'v':
+               verbose = true;
+               break;
        case 'h':
                argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
                break;
@@ -76,6 +81,13 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
        return 0;
 }
 
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+       if (level == LIBBPF_DEBUG && !verbose)
+               return 0;
+       return vfprintf(stderr, format, args);
+}
+
 static void sig_int(int signo)
 {
        exiting = 1;
@@ -134,6 +146,7 @@ int main(int argc, char **argv)
                return err;
 
        libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+       libbpf_set_print(libbpf_print_fn);
 
        obj = solisten_bpf__open();
        if (!obj) {