strchr() in C.
==== Substr ====
Shell uses zero-based indexing. When substring expansion of the form ${... abcABC123ABCabc
# 0123456789.....
# 0-based indexing.
echo ${stringZ:0} ... abcABC123ABCabc
# 123456789......
# 1-based indexing.
echo `expr substr $stringZ 1 2` ... odd number of backslashes (\). position is a zero-based index.
mbfl_string_is_equal_unquoted_char st
