The shell command interpreter converts the command name to lower case before searching the table of registered commands. You can see this in shell.c line 109. Hence, command names must be in lower case. The reason that the help command works correctly with mixed case names is that this code does not convert the command name to lower case before searching the command table. You can see this in sh_help.c line 74.
The shell command interpreter converts the command name to lower case before searching the table of registered commands. You can see this in shell.c line 109. Hence, command names must be in lower case. The reason that the help command works correctly with mixed case names is that this code does not convert the command name to lower case before searching the command table. You can see this in sh_help.c line 74.