github.com/tompao/docker@v1.9.1/builder/dockerfile/words (about) 1 hello | hello 2 he'll'o | hello 3 he'llo | hello 4 he\'llo | he'llo 5 he\\'llo | he\llo 6 abc\tdef | abctdef 7 "abc\tdef" | abc\tdef 8 'abc\tdef' | abc\tdef 9 hello\ | hello 10 hello\\ | hello\ 11 "hello | hello 12 "hello\" | hello" 13 "hel'lo" | hel'lo 14 'hello | hello 15 'hello\' | hello\ 16 "''" | '' 17 $. | $. 18 $1 | 19 he$1x | hex 20 he$.x | he$.x 21 he$pwd. | he. 22 he$PWD | he/home 23 he\$PWD | he$PWD 24 he\\$PWD | he\/home 25 he\${} | he${} 26 he\${}xx | he${}xx 27 he${} | he 28 he${}xx | hexx 29 he${hi} | he 30 he${hi}xx | hexx 31 he${PWD} | he/home 32 he${.} | error 33 he${XXX:-000}xx | he000xx 34 he${PWD:-000}xx | he/homexx 35 he${XXX:-$PWD}xx | he/homexx 36 he${XXX:-${PWD:-yyy}}xx | he/homexx 37 he${XXX:-${YYY:-yyy}}xx | heyyyxx 38 he${XXX:YYY} | error 39 he${XXX:+${PWD}}xx | hexx 40 he${PWD:+${XXX}}xx | hexx 41 he${PWD:+${SHELL}}xx | hebashxx 42 he${XXX:+000}xx | hexx 43 he${PWD:+000}xx | he000xx 44 'he${XX}' | he${XX} 45 "he${PWD}" | he/home 46 "he'$PWD'" | he'/home' 47 "$PWD" | /home 48 '$PWD' | $PWD 49 '\$PWD' | \$PWD 50 '"hello"' | "hello" 51 he\$PWD | he$PWD 52 "he\$PWD" | he$PWD 53 'he\$PWD' | he\$PWD 54 he${PWD | error 55 he${PWD:=000}xx | error 56 he${PWD:+${PWD}:}xx | he/home:xx 57 he${XXX:-\$PWD:}xx | he$PWD:xx 58 he${XXX:-\${PWD}z}xx | he${PWDz}xx