lex - Stop program execution when there is error -

i like stop execution of program when facing error. how when using lex? can call normal c exit like:

exit( status ); 

or there more neat way lex?

you can - but:

• just printing message standard error , exiting lex does—when encounters fatal error, e.g., buffer allocation problems. see example yy_fatal_error, used purpose. can overridden, e.g., error recovery routine.
• a typical lexer not exit error: returns state information parser decides whether state legal.

if lexer serves parser, exiting lexer make sense.

further reading:

• does yy_fatal_error require call exit?
• re: ungraceful handling of fatal flex errors
• flex yy_fatal_error exist that. want handler application