# nl > A utility for numbering lines, either from a file, or from standard input. > More information: . - Number non-blank lines in a file: `nl {{file}}` - Read from standard output: `cat {{file}} | nl {{options}} -` - Number only the lines with printable text: `nl -t {{file}}` - Number all lines including blank lines: `nl -b a {{file}}` - Number only the body lines that match a basic regular expression (BRE) pattern: `nl -b p'FooBar[0-9]' {{file}}`