utils.compress
Lua function

utils.compress

Summary

Compress a string

Prototype

s = utils.compress (s [, method] )


Description

Compresses string s and returns the compressed form. Note that it may contain nulls (bytes with a zero value).

The optional argument 'method' indicates the level of compression you want.


  • 0 = no compression
  • 1 = best speed
    ....
  • 9 = best compression


The default, if omitted, is 6.

eg.


comp = utils.compress ("this is a fine thing")


For short strings the compressed data may be longer than the uncompressed data because of a 12-byte "compression information" header that is prepended to the compressed data. For longer text (such as the section above about the Lua sandbox), the compression ratio is about 50%.

See Also ...

Topics

DOC_lua_base Lua base functions
DOC_lua_bc Lua bc (big number) functions
DOC_lua_bit Lua bit manipulation functions
DOC_lua_coroutines Lua coroutine functions
DOC_lua_debug Lua debug functions
DOC_lua_io Lua io functions
DOC_lua_math Lua math functions
DOC_lua_os Lua os functions
DOC_lua_package Lua package functions
DOC_lua_rex Lua PCRE regular expression functions
DOC_lua Lua script extensions
DOC_lua_string Lua string functions
DOC_lua_tables Lua table functions
DOC_lua_utils Lua utilities
DOC_scripting Scripting

Lua functions

LUA_utils.base64decode utils.base64decode (Decode a string which was base-64 encoded)
LUA_utils.base64encode utils.base64encode (Encode a string with base-64 encoding)
LUA_utils.choose utils.choose (Display a combo box with choices in it)
LUA_utils.decompress utils.decompress (Decompress a string)
LUA_utils.editbox utils.editbox (Display a large message box and get free-format reply)
LUA_utils.edit_distance utils.edit_distance (Returns the Levenshtein Edit Distance between two words)
LUA_utils.filepicker utils.filepicker (Invokes the Windows standard "file picker" dialog box)
LUA_utils.fromhex utils.fromhex (Convert a string from hex)
LUA_utils.functionlist utils.functionlist (Returns a table of MUSHclient world function names)
LUA_utils.hash utils.hash (Hash a string, returning the hex codes)
LUA_utils.info utils.info (Information about directories)
LUA_utils.inputbox utils.inputbox (Display a message box and get free-format reply)
LUA_utils.listbox utils.listbox (Display a dialog box with choices in it in a single selection list box)
LUA_utils.md5 utils.md5 (Hash a string using the 128-bit MD5 algorithm)
LUA_utils.metaphone utils.metaphone (Returns metaphones (sound-alike codes) for the supplied word)
LUA_utils.msgbox utils.msgbox (Display a message box and get a response)
LUA_utils.multilistbox utils.multilistbox (Display a dialog box with choices in it in a multiple selection list box)
LUA_utils.readdir utils.readdir (Read a disk directory into a table)
LUA_utils.sha256 utils.sha256 (Hash a string using a 256-bit hash)
LUA_utils.spellcheckdialog utils.spellcheckdialog (Spell-checker dialog)
LUA_utils.split utils.split (Split a delimited string into a table)
LUA_utils.tohex utils.tohex (Convert a string into hex)
LUA_utils.utf8decode utils.utf8decode (Encodes a series of Unicode codes into a UTF-8 string)
LUA_utils.utf8encode utils.utf8encode (Encodes a series of Unicode codes into a UTF-8 string)
LUA_utils.utf8valid utils.utf8valid (Checks if a UTF-8 string is valid)
LUA_utils.xmlread utils.xmlread (Parses an XML string into a nested table)

(Help topic: lua=utils.compress)

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