I just kicked off a bunch of instances (17) of my program to test them running concurrently. This is what the terminal output looked like near the end.
[9] Done perl test.pl -a
[10] Done perl test.pl -a
[11] Done perl test.pl -a
[12] Done perl test.pl -a
[13] Done perl test.pl -a
[14] Done perl test.pl -a
[15] Done perl test.pl -a
[16]- Done perl test.pl -a
[17]+ Done perl test.pl -a
The 17th was the last one. I was wondering, what does the [16]- and [17]+ mean? Just that they were the last two processes to finish?
From §7.1 "Job Control Basics" in the Bash Reference Manual:
Job number
nmay be referred to as ‘%n’. The symbols ‘%%’ and ‘%+’ refer to the shell’s notion of the current job, which is the last job stopped while it was in the foreground or started in the background. A single ‘%’ (with no accompanying job specification) also refers to the current job. The previous job may be referenced using ‘%-’. If there is only a single job, ‘%+’ and ‘%-’ can both be used to refer to that job. In output pertaining to jobs (e.g., the output of thejobscommand), the current job is always flagged with a ‘+’, and the previous job with a ‘-’.
(emphases mine).
So it's not that they were the last ones to finish, but that they were the last ones to be started in the background.