X-Git-Url: http://sjero.net/git/?p=wget;a=blobdiff_plain;f=doc%2Fwget.texi;h=9b964fde258c3ff92ec4a19d433aed23b0f77ccd;hp=7419c0d1a59eb7bd1eedfa80a79a3cc987e6f4d7;hb=2c41d783c62f1252701b8cb5a8adbcf8efbf0275;hpb=3afb9c659a145f1f153fc203e3a68b8a4e938585 diff --git a/doc/wget.texi b/doc/wget.texi index 7419c0d1..9b964fde 100644 --- a/doc/wget.texi +++ b/doc/wget.texi @@ -701,6 +701,26 @@ seconds per file. Note that this option is turned on by default in the global @file{wgetrc} file. +@cindex wait, random +@cindex random wait +@itemx --random-wait +Some web sites may perform log analysis to identify retrieval programs +such as Wget by looking for statistically significant similarities in +the time between requests. This option causes the time between requests +to vary between 0 and 2 * @var{wait} seconds, where @var{wait} was +specified using the @samp{-w} or @samp{--wait} options, in order to mask +Wget's presence from such analysis. + +A recent article in a publication devoted to development on a popular +consumer platform provided code to perform this analysis on the fly. +Its author suggested blocking at the class C address level to ensure +automated retrieval programs were blocked despite changing DHCP-supplied +addresses. + +The @samp{--random-wait} option was inspired by this ill-advised +recommendation to block many unrelated users from a web site due to the +actions of one. + @cindex proxy @item -Y on/off @itemx --proxy=on/off @@ -2168,6 +2188,10 @@ Wait @var{n} seconds between retrievals---the same as @samp{-w}. Wait up to @var{n} seconds between retries of failed retrievals only---the same as @samp{--waitretry}. Note that this is turned on by default in the global @file{wgetrc}. + +@item randomwait = on/off +Turn random between-request wait times on or off. The same as +@samp{--random-wait}. @end table @node Sample Wgetrc, , Wgetrc Commands, Startup File