# flex > Lexical analyser generator. Based on `lex`. > Given the specification for a lexical analyser, generates C code implementing it. > More information: . - Generate an analyser from a flex file: `flex {{analyser.l}}` - Specify the output file: `flex --outfile {{analyser.c}} {{analyser.l}}` - Compile a C file generated by flex: `cc {{path/to/lex.yy.c}} --output {{executable}}`