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-a Generate ANSI standard C output code, i.e., function prototypes.
-c Generate comparison code using strncmp rather than strcmp.
-C Make the contents of generated lookup tables constant, i.e., readonly.
-d Enables the debugging option (produces verbose output to the standard error).
-D Handle keywords that hash to duplicate values. This is useful
for certain highly redundant keyword sets. It enables the -S option.
-e Allow user to provide a string containing delimiters used to separate
keywords from their attributes. Default is ",\n"
-E Define constant values using an enum local to the lookup function
rather than with defines
-f Generate the gen-perf.hash function ``fast.'' This decreases GPERF's
running time at the cost of minimizing generated table-size.
The numeric argument represents the number of times to iterate when
resolving a collision. `0' means ``iterate by the number of keywords.''
-g Assume a GNU compiler, e.g., g++ or gcc. This makes all generated
routines use the ``inline'' keyword to remove cost of function calls.
-G Generate the static table of keywords as a static global variable,
rather than hiding it inside of the lookup function (which is the
default behavior).
-h Prints this mesage.
-H Allow user to specify name of generated hash function. Default
is `hash'.
-i Provide an initial value for the associate values array. Default is 0.
Setting this value larger helps inflate the size of the final table.
-j Affects the ``jump value,'' i.e., how far to advance the associated
character value upon collisions. Must be an odd number, default is 5.
-k Allows selection of the key positions used in the hash function.
The allowable choices range between 1-126, inclusive. The positions
are separated by commas, ranges may be used, and key positions may
occur in any order. Also, the meta-character '*' causes the generated
hash function to consider ALL key positions, and $ indicates the
``final character'' of a key, e.g., $,1,2,4,6-10.
-K Allow use to select name of the keyword component in the keyword structure.
-l Compare key lengths before trying a string comparison. This helps
cut down on the number of string comparisons made during the lookup.
-L Generates code in the language specified by the option's argument. Languages
handled are currently C++ and C. The default is C.
-n Do not include the length of the keyword when computing the hash function
-N Allow user to specify name of generated lookup function. Default
name is `in_word_set.'
-o Reorders input keys by frequency of occurrence of the key sets.
This should decrease the search time dramatically.
-p Changes the return value of the generated function ``in_word_set''
from its default boolean value (i.e., 0 or 1), to type ``pointer
to wordlist array'' This is most useful when the -t option, allowing
user-defined structs, is used.
-r Utilizes randomness to initialize the associated values table.
-s Affects the size of the generated hash table. The numeric argument
for this option indicates ``how many times larger or smaller'' the associated
value range should be, in relationship to the number of keys, e.g. a value of 3
means ``allow the maximum associated value to be about 3 times larger than the
number of input keys.'' Conversely, a value of -3 means ``make the maximum
associated value about 3 times smaller than the number of input keys.
A larger table should decrease the time required for an unsuccessful search,
at the expense of extra table space. Default value is 1.
-S Causes the generated C code to use a switch statement scheme, rather
than an array lookup table. This can lead to a reduction in both
time and space requirements for some keyfiles. The argument to
this option determines how many switch statements are generated.
A value of 1 generates 1 switch containing all the elements, a value of 2
generates 2 tables with 1/2 the elements in each table, etc. This
is useful since many C compilers cannot correctly generate code for
large switch statements.
-t Allows the user to include a structured type declaration for
generated code. Any text before %% is consider part of the type
declaration. Key words and additional fields may follow this, one
group of fields per line.
-T Prevents the transfer of the type declaration to the output file.
Use this option if the type is already defined elsewhere.
-v Prints out the current version number
-Z Allow user to specify name of generated C++ class. Default
name is `Perfect_Hash.'
Usage: ../src/gperf [-acCdDef[num]gGhH<hashname>i<init>jk<keys>K<keyname>lL<language>nN<function name>oprs<size>S<switches>tTvZ<class name>].
(type ../src/gperf -h for help)
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