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GNU Info (flex.info)End-of-file rulesEnd-of-file rules ***************** The special rule "<<EOF>>" indicates actions which are to be taken when an end-of-file is encountered and yywrap() returns non-zero (i.e., indicates no further files to process). The action must finish by doing one of four things: - assigning `yyin' to a new input file (in previous versions of flex, after doing the assignment you had to call the special action `YY_NEW_FILE'; this is no longer necessary); - executing a `return' statement; - executing the special `yyterminate()' action; - or, switching to a new buffer using `yy_switch_to_buffer()' as shown in the example above. <<EOF>> rules may not be used with other patterns; they may only be qualified with a list of start conditions. If an unqualified <<EOF>> rule is given, it applies to _all_ start conditions which do not already have <<EOF>> actions. To specify an <<EOF>> rule for only the initial start condition, use <INITIAL><<EOF>> These rules are useful for catching things like unclosed comments. An example: %x quote %% ...other rules for dealing with quotes... <quote><<EOF>> { error( "unterminated quote" ); yyterminate(); } <<EOF>> { if ( *++filelist ) yyin = fopen( *filelist, "r" ); else yyterminate(); } automatically generated by info2www version 1.2.2.9 |