# first try some invalid patterns
# do all of these in subshells since it's supposed to error out
# (set argv0 to "SHELL" to avoid "/path/to/shell: blah" in error messages)
export var=0123456789
"$THIS_SH" -c 'echo ${:}' SHELL
"$THIS_SH" -c 'echo ${::}' SHELL
"$THIS_SH" -c 'echo ${:1}' SHELL
"$THIS_SH" -c 'echo ${::1}' SHELL

#this also is not valid in bash, hush accepts it:
"$THIS_SH" -c 'echo ${var:}' SHELL

# then some funky ones
"$THIS_SH" -c 'echo ${?:0}' SHELL

# now some valid ones
set --; echo "1    =|${1}|"
set --; echo "1:1  =|${1:1}|"
set --; echo "1:1:2=|${1:1:2}|"
set --; echo "1::2 =|${1::2}|"
set --; echo "1:1: =|${1:1:}|"
set --; echo "1::  =|${1::}|"

set -- 0123; echo "1    =|${1}|"
set -- 0123; echo "1:1  =|${1:1}|"
set -- 0123; echo "1:1:2=|${1:1:2}|"
set -- 0123; echo "1::2 =|${1::2}|"
set -- 0123; echo "1:1: =|${1:1:}|"
set -- 0123; echo "1::  =|${1::}|"

unset f; echo "f    =|$f|"
unset f; echo "f:1  =|${f:1}|"
unset f; echo "f:1:2=|${f:1:2}|"
unset f; echo "f::2 =|${f::2}|"
unset f; echo "f:1: =|${f:1:}|"
unset f; echo "f::  =|${f::}|"

f=; echo "f    =|$f|"
f=; echo "f:1  =|${f:1}|"
f=; echo "f:1:2=|${f:1:2}|"
f=; echo "f::2 =|${f::2}|"
f=; echo "f:1: =|${f:1:}|"
f=; echo "f::  =|${f::}|"

f=a; echo "f    =|$f|"
f=a; echo "f:1  =|${f:1}|"
f=a; echo "f:1:2=|${f:1:2}|"
f=a; echo "f::2 =|${f::2}|"
f=a; echo "f:1: =|${f:1:}|"
f=a; echo "f::  =|${f::}|"

f=0123456789; echo "f    =|$f|"
f=0123456789; echo "f:1  =|${f:1}|"
f=0123456789; echo "f:1:2=|${f:1:2}|"
f=0123456789; echo "f::2 =|${f::2}|"
f=0123456789; echo "f:1: =|${f:1:}|"
f=0123456789; echo "f::  =|${f::}|"

echo "Substrings from special vars"
echo '?    '"=|$?|"
echo '?:1  '"=|${?:1}|"
echo '?:1:2'"=|${?:1:2}|"
echo '?::2 '"=|${?::2}|"
echo '?:1: '"=|${?:1:}|"
echo '?::  '"=|${?::}|"
set -- 1 2 3 4 5 6 7 8 9 10 11
echo '#    '"=|$#|"
echo '#:1  '"=|${#:1}|"
echo '#:1:2'"=|${#:1:2}|"
echo '#::2 '"=|${#::2}|"
echo '#:1: '"=|${#:1:}|"
echo '#::  '"=|${#::}|"

echo "Substrings with expressions"
f=01234567; echo 'f            '"=|$f|"
f=01234567; echo 'f:1+1:2+2    '"=|${f:1+1:2+2}|"
f=01234567; echo 'f:-1:2+2     '"=|${f:-1:2+2}|"
f=01234567; echo 'f:1:f        '"=|${f:1:f}|"
f=01234567; echo 'f:1:$f       '"=|${f:1:$f}|"
f=01234567; echo 'f:1:${f}     '"=|${f:1:${f}}|"
f=01234567; echo 'f:1:${f:3:1} '"=|${f:1:${f:3:1}}|"
f=01234567; echo 'f:1:1`echo 1`'"=|${f:1:`echo 1`}|"

echo Done