doesn't work the bash script to check given single character is in lower case or uppercase
121082
Why does [A-Z] match lowercase letters in bash?
94701
How to make regex accept only uppercase and lowercase letters with accents in java?
13278
How do I make my string comparison case-insensitive?
3265
How can I test if a variable is empty or contains only spaces?
157168
How do I use a file grep comparison inside a bash if/else statement?
102882
In bash, how do I escape an exclamation mark?
10610
How can I check if a single character appears in a string?
92237
Shell test to find a pattern in a string
61897
Correct Bash and shell script variable capitalization
37165
Finding Uppercase Character then Adding Space
40999
Using \in with uppercase letters does not look good
52106
bash if -a vs -e option
124479
Check if a String contains a special character
132593
Regular expression for upper case letter only in JavaScript
56072
How do I compare two string variables in an 'if' statement in Bash?
19892
Why bash "read -t 0" does not see input?
98104
How do I lowercase a string in Python?