flex

Lexical analyzer generator. A rewrite of lex with extensions to the POSIX specification. Given the specification for a lexical analyzer, generates C code implementing it. Note: long options don’t work on OpenBSD. More information: https://manned.org/flex.

• Generate an analyzer from a flex file, storing it to the file lex.yy.c:

lex analyzer.l

• Write analyzer to stdout:

lex --stdout|t analyzer.l

• Specify the output file:

lex analyzer.l -o analyzer.c

• Generate a Batch scanner instead of an interactive scanner:

lex -B analyzer.l

• Compile a C file generated by Lex:

cc path/to/lex.yy.c --output executable