Bạn có thể đã ban hành một lệnh như thế này:
wget -c http://downloads.sourceforge.net/project/zorin-os/9/zorin-os-9-core-32.iso?r=http%3A%2F%2Fzorinos.com%2Fdownload9.html&ts=1460659842&something-else
Lệnh đó chứa ký tự đặc biệt &
, được sử dụng để chạy đồng thời nhiều tiến trình . Lệnh đó đang được hiểu là ba (hoặc nhiều) lệnh:
# First command (the one that you see after [1]):
wget -c http://downloads.sourceforge.net/project/zorin-os/9/zorin-os-9-core-32.iso?r=http%3A%2F%2Fzorinos.com%2Fdownload9.html
# Second command (the one that you see after [2]):
ts=1460659842
# Third command (the one which output should be above the "Done" lines):
something-else
Đây là một ví dụ có thể giúp bạn hiểu rõ hơn:
# Here I'm launching three 'echo' commands, the first two in background, the third in foreground
andrea@andrea-laptop:~$ echo first & echo second & echo third
[1] 5033 # This is bash telling me that the first process was started with job number 1 and PID 5033
first # This is the output from the first process
[2] 5034 # This is bash telling me that the second process was started with job number 2 and PID 5034
third # This is the output from the third process
second # This is the output from the second process
andrea@andrea-laptop:~$
[1]- Done echo first # This is bash telling me that the first background job has quit
[2]+ Done echo second # This is bash telling me that the second background job has quit
Bạn nên trích dẫn đúng URL để tránh điều này và các hiệu ứng khó chịu khác:
wget -c 'http://downloads.sourceforge.net/project/zorin-os/9/zorin-os-9-core-32.iso?r=http%3A%2F%2Fzorinos.com%2Fdownload9.html&ts=1460659842&something-else'