summaryrefslogtreecommitdiffhomepage
path: root/shell/ash_test/ash-parsing/and_or_and_backgrounding.tests
blob: 204d444900fd570da5470dca253a0912d707fb6f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
# According to this doc, && || have higher precedence than ; &.
# See example below.
# Precedence of ; is not a problem in practice. Precedence of & is.
#
#http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
#
#2.9.3 Lists
#
#An AND-OR list is a sequence of one or more pipelines separated by
#the operators "&&" and "||" .
#
#A list is a sequence of one or more AND-OR lists separated by the operators
#';' and '&' and optionally terminated by ';', '&', or <newline>.
#
#The operators "&&" and "||" shall have equal precedence and shall be
#evaluated with left associativity. For example, both of the following
#commands write solely bar to standard output:
#
#    false && echo foo || echo bar
#    true || echo foo && echo bar
#
#A ';' or <newline> terminator shall cause the preceding AND-OR list
#to be executed sequentially; an '&' shall cause asynchronous execution
#of the preceding AND-OR list.

echo First && sleep 0.2 && echo Third &
sleep 0.1
echo Second
wait
echo Done