How to iterate over an array?

[yahaa]

The following is my pbftrace code, how can I iterate the args.envp ?

#!/usr/bin/env bpftrace

BEGIN
{
    printf("Tracing scp attempts from the server... Hit Ctrl-C to end.\n");
}

// trace scp
tracepoint:syscalls:sys_enter_execve
/ str(args.filename) == "/usr/bin/scp" /
{

    $user="";
    $conn="";

    $i = 0;
    while ($i<100){
        if (strcontains(str(args.envp[$i]),"USER") == 1) {
            $user=str(args.envp[$i]);
        }

        if (strcontains(str(args.envp[$i]),"SSH_CONNE") == 1) {
            $conn=str(args.envp[$i]);
        }

        $i++;
    }

    printf("UID=%d %s %s PID=%d COMM=%s argv=",uid,$user,$conn,pid,comm);
    join(args.argv);
}

I run this code, and go the following errors:

trace-scp.bt:18:12-42: ERROR: The array index operator [] only accepts literal integer indices.
        if (strcontains(str(args.envp[$i]),"USER") == 1) {
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
trace-scp.bt:19:13-36: ERROR: The array index operator [] only accepts literal integer indices.
            $user=str(args.envp[$i]);
            ~~~~~~~~~~~~~~~~~~~~~~~
trace-scp.bt:22:12-42: ERROR: The array index operator [] only accepts literal integer indices.
        if (strcontains(str(args.envp[$i]),"SSH_CONNE") == 1) {
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
trace-scp.bt:23:13-36: ERROR: The array index operator [] only accepts literal integer indices.
            $conn=str(args.envp[$i]);
            ~~~~~~~~~~~~~~~~~~~~~~~

It mean that I can only visit the args.envp using the specify number index? such as args.envp[0], args.envp[1] ... args.envp[10] ....?

[jordalgo]

Edited: Something like this works but it seems that strcontains is broken. Will file a bug and look into it:

$i = 0;
$last = "";
while ($i<10) {
     $last = str(*(args.envp + $i));
     $i++;
 }
print(($last));

[jordalgo]

#3374

[yahaa]

Thanks.