mirror of
https://github.com/topjohnwu/ndk-busybox.git
synced 2024-11-25 04:39:48 +00:00
90 lines
1.9 KiB
Plaintext
90 lines
1.9 KiB
Plaintext
# try running this with bash, ksh, ash, and hush.
|
|
|
|
# simple quoting rules.
|
|
echo a b
|
|
echo "a b"
|
|
echo a "" b
|
|
echo a '' b
|
|
echo hello?
|
|
echo "hello?"
|
|
echo t* hello
|
|
echo t\* hello
|
|
|
|
# quick and painless exit for lash
|
|
if false; then true; exit; fi
|
|
|
|
# fairly simple command substitution
|
|
echo `echo -e foo\\\necho bar`
|
|
|
|
echo THIS IS A TEST >foo
|
|
cat $(echo FOO | tr 'A-Z' 'a-z')
|
|
cat foo | tr 'A-Z' 'a-z'
|
|
cat $(echo FOO | tr 'A-Z' 'a-z') | tr 'A-Z' 'a-z'
|
|
|
|
cat foo | if true; then tr 'A-Z' 'a-z'; else echo bar1; fi
|
|
cat foo | if false; then tr 'A-Z' 'a-z'; else echo bar2; fi
|
|
if true; then tr 'A-Z' 'a-z'; else echo bar3; fi <foo
|
|
if false; then tr 'A-Z' 'a-z'; else echo bar4; fi <foo
|
|
if true || false; then echo foo; else echo bar5; fi
|
|
if true && false; then echo bar6; else echo foo; fi
|
|
|
|
# basic distinction between local and env variables
|
|
unset FOO
|
|
FOO=bar env | grep FOO
|
|
echo "but not here: $FOO"
|
|
FOO=bar
|
|
env | grep FOO
|
|
echo "yes, here: $FOO"
|
|
FOO=
|
|
echo a $FOO b
|
|
echo "a $FOO b"
|
|
|
|
# not quite so basic variables. Credit to Matt Kraai.
|
|
unset FOO
|
|
FOO=bar
|
|
export FOO
|
|
env | grep FOO
|
|
unset FOO
|
|
export FOO=bar
|
|
FOO=baz
|
|
env | grep FOO
|
|
|
|
# interaction between environment variables and if/then and subshells
|
|
FOO=default
|
|
if true; then FOO=new; fi
|
|
echo $FOO
|
|
FOO=default
|
|
(FOO=bogus)
|
|
echo $FOO
|
|
|
|
# make sure we can duplicate file descriptors properly
|
|
echo replacement >foo 2>&1
|
|
cat foo
|
|
cat doesnt_exist >foo 2>&1
|
|
tr 'a-z' 'A-Z' <foo
|
|
|
|
# fairly simple example of hush expanding variables too early
|
|
unset TMP
|
|
rm -f fish
|
|
TMP=fish && >$TMP
|
|
ls fish
|
|
|
|
# ash, lash, and hush do not create wish; bash and ksh do.
|
|
# Thanks to Tapani Tarvainen <tt@mit.jyu.fi> for this stress test.
|
|
unset TMP
|
|
rm -f wish
|
|
TMP=wish >$TMP
|
|
ls wish
|
|
|
|
# The following example shows that hush's parser is
|
|
# not _really_ Bourne compatible
|
|
echo "echo Hello World" >"a=b"
|
|
unset a
|
|
chmod a+x "a=b"
|
|
PATH=$PATH:.
|
|
"a=b"
|
|
echo $a
|
|
|
|
# assuming the shell wasn't too buggy, clean up the mess
|
|
rm -f a=b wish fish foo
|