1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
-a Generate ANSI standard C output code, i.e., function prototypes.
-b Generate code for Linear Search.
-B Generate code for Binary Search.
-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.
-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.''
-F Provided expression will be used to assign default values in keyword
table, i.e., the fill value. Default is "".
-g Make generated routines use ``inline'' to remove function overhead.
-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 message.
-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.
-I Generate comparison code using case insensitive string comparison, e.g.,
strncasecmp or strcasecmp.
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.
-J Skips '#include <string.h>' part in the output.
-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.
-m Avoids the warning about identical hash values. This is valid
only if the -D option is enabled.
-M Skips class definition in the output. This is valid only in C++ mode.
-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.
-O Optimize the generated lookup function by assuming that all input
keywords are members of the keyset from the keyfile.
-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 and exits with a value of 0
-V Exits silently with a value of 0.
-Z Allow user to specify name of generated C++ class. Default
name is `Perfect_Hash.'
Usage: ../src/gperf [-abBcCdDef[num]gGhH<hashname>i<init>IjJk<keys>K<keyname>lL<language>mMnN<function name>oOprs<size>S<switches>tTvVZ<class name>].
(type ../src/gperf -h for help)
|
