z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

lex
Options
For a description of the typedefs, constants, variables, macros, and functions in the
table file, which can be used to access the lexical analyzer’s variables or to control
its operations, see z/OS UNIX System Services Programming Tools.
–a Generates 8-bit tables instead of 7-bit tables. On systems with 8-bit
character sets (such as this one), this option is always enabled.
–c Generates C code. Because this is the default, this option is provided only
for compatibility with other implementations.
–h Prints a brief list of the options and quits.
–l Suppresses #line directives in the generated code.
–n Suppresses the display of table sizes by the –v option. If you did not
specify –v and their are no table sizes specified in file.1, lex behaves as
though you specified –n.
–o file.c
Writes the lexical analyzer (internal state tables) onto the named output file,
instead of the default file lex.yy.c.
–P proto
Uses the named code file, instead of the default prototype file /etc/yylex.c.
–p prefix
Uses the given prefix instead of the prefix yy in the generated code.
–T Writes a description of the analyzer onto the file l.output.
–t Writes the lexical analyzer onto standard output (stdout) instead of the file
lex.yy.c.
–v Displays the space used by the various internal tables. Normally lex
displays these statistics on stdout, but if you also specified the –t option, it
displays them on stderr. If you did not choose this option and file.1
specifies table sizes, lex still displays these statistics unless you specified
the –n option.
The lex library contains a number of functions essential for use with lex. These
functions are described in z/OS UNIX System Services Programming Tools . The
actual library to use depends on your system and compiler. For z/OS programs, you
should use –ll.
Some lex programs can cause one or more tables within lex to overflow. These
tables are the NFA, DFA, and move tables; lex displays an appropriate message if
an overflow occurs. You can change table sizes by inserting the appropriate line
into the definition section of the lex input, with the number size giving the number of
entries to use. This is shown in Table 15.
Table 15. Internal Table Sizes (lex command)
Line Table Size Affected Default
%esize Number of NFA entries 1000
%nsize Number of DFA entries 500
%psize Number of move entries 2500
You can often reduce the NFA and DFA space to make room for more move entries.
344 z/OS V1R9.0 UNIX System Services Command Reference