Index[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Z] ! (exclamation points) logical comparison operators number comparison operators != (is not equal) symbol string comparison operators string expression operators # run-parts lines (/etc/crontab files) #! (shebang) 2nd $# built-in variables $* built-in variables $0 built-in variables $? built-in variables & (ampersand), shell background processing && (double ampersand) number comparison operators * (asterisks) Python shell pattern-matching searches wildcards + operators (Python) / (backslashes) as escape characters 00-INDEX files ' (single quotes), maintaining shell strings with unexpanded variables " (double quotes), resolving variables in shell strings with embedded spaces 1000BASE-T NIC (network interface cards) 1000BASE-X NIC (network interface cards) 100BASE-T NIC (network interface cards) 10BASE-T NIC (network interface cards) 64-bit Ubuntu : (slices), copying lists in Python < (greater than) number comparison operators = (equal sign) number comparison operators string expression operators == (double equal sign) string comparison operators > (less than) number comparison operators ? (question mark), shell pattern-matching searches ` (backticks), replacing strings with output | (bar operators) || (double pipe) number comparison operators string concatenation function |