1 LYNX NAME lynx - a general purpose distributed information browser for the World Wide Web 2 SYNOPSIS Lynx [options] [path or URL] use "lynx -help" to display a complete list of current options. 2 DESCRIPTION Lynx is a fully-featured World Wide Web (WWW) client for users running cursor-addressable, character-cell display devices (e.g., vt100 terminals, vt100 emulators running on PCs or Macs, or any other "curses-oriented" display). It will display hypertext markup language (HTML) documents con- taining links to files residing on the local system, as well as files residing on remote systems running Gopher, HTTP, FTP, WAIS, and NNTP servers. Current versions of Lynx run on Unix, VMS, Windows95/NT, 386DOS and OS/2 EMX. Lynx can be used to access information on the World Wide Web, or to build information systems intended primarily for local access. For example, Lynx has been used to build several Campus Wide Information Systems (CWIS). In addition, Lynx can be used to build systems isolated within a single LAN. 2 OPTIONS At start up, Lynx will load any local file or remote URL specified at the command line. For help with URLs, press "?" or "h" while running Lynx. Then follow the link titled, "Help on URLs." - If the argument is only '-', then Lynx expects to receive arguments from stdin. This is to allow for the potentially very long command line that can be associated with the -get_data or -post_data arguments (see below). Encase it in double-quotes ("-"). -accept_all_cookies accept all cookies. -anonymous used to specify the anonymous account. -assume_charset=MIMEname charset for documents that don't specify it. -assume_local_charset=MIMEname charset assumed for local files. -assume_unrec_charset=MIMEname use this instead of unrecognized charsets. -auth=ID:PASSWD set authorization ID and password for protected documents at startup. Be sure to protect any script files which use this switch. -base prepend a request URL comment and BASE tag to text/html outputs for -source dumps. -blink forces high intensity bg colors for color mode, if available and supported by the terminal. Lynx needs to be compiled with the slang library for this flag. -book use the bookmark page as the startfile. The default or command line startfile is still set for the Main screen command, and will be used if the bookmark page is unavailable or blank. -buried_news toggles scanning of news articles for buried references, and converts them to news links. Not recommended because email addresses enclosed in angle brackets will be converted to false news links, and uuencoded messages can be trashed. -cache=NUMBER set the NUMBER of documents cached in memory. The default is 10. -case enable case-sensitive string searching. -cfg=FILENAME specifies a Lynx configuration file other than the default lynx.cfg. -child exit on left-arrow in startfile, and disable save to disk. -color forces color mode on, if available. Default color control sequences which work for many terminal types are assumed if the terminal capability description does not specify how to handle color. Lynx needs to be compiled with the slang library for this flag. A saved show_color=always setting found in a .lynxrc file at startup has the same effect. A saved show_color=always found in .lynxrc on startup is overridden by this flag. -cookies toggles handling of Set-Cookie headers. -cookie_file=FILENAME specifies a file to use to store cookies. -crawl with -traversal, output each page to a file. with -dump, format output as with -traversal, but to stdout. -debug_partial incremental display stages with MessageSecs delay -display=DISPLAY set the display variable for X rexec-ed programs. -dump dumps the formatted output of the default document or one specified on the command line to standard out. This can be used in the following way: lynx -dump http://www.crl.com/~subir/lynx.html -editor=EDITOR enable edit mode using the specified EDITOR. (vi, ed, emacs, etc.) -emacskeys enable emacs-like key movement. -enable_scrollback toggles compatibility with comm programs' scrollback keys (may be incompatible with some curses packages). -error_file=FILE define a file where Lynx will report HTTP access codes. -exec enable local program execution (normally not configured). -fileversions include all versions of files in local VMS directory listings. -force_html forces the first document to be interpreted as HTML. -force_secure toggles forcing of the secure flag for SSL cookies. -forms_options toggles the style of options (menu or forms). -from toggles transmissions of From headers. -ftp disable ftp access. -get_data send form data from stdin using GET method and dump results. -head send a HEAD request for the mime headers. -help print the Lynx command syntax usage message. -hiddenlinks=[option] control the display of hidden links. + merge hidden links show up as bracketed numbers and are numbered together with other links in the sequence of their occurrence in the document. + listonly hidden links are shown only on L)ist screens and listings generated by -dump or from the P)rint menu, but appear separately at the end of those lists. This is the default behavior. + ignore hidden links do not appear even in listings. -historical toggles use of '>' or '-->' as a terminator for comments. -homepage=URL set homepage separate from start page. -image_links toggles inclusion of links for all images. -index=URL set the default index file to the specified URL. -ismap toggles inclusion of ISMAP links when client-side MAPs are present. -link=NUMBER starting count for lnk#.dat files produced by -crawl. -localhost disable URLs that point to remote hosts. -locexec enable local program execution from local files only (if Lynx was compiled with local execution enabled). -mime_header prints the MIME header of a fetched document along with its source. -minimal toggles minimal versus valid comment parsing. -newschunksize=NUMBER number of articles in chunked news listings. -newsmaxchunk=NUMBER maximum news articles in listings before chunking. -nobrowse disable directory browsing. -nocc disable Cc: prompts for self copies of mailings. Note that this does not disable any CCs which are incorporated within a mailto URL or form ACTION. -nocolor force color mode off, overriding terminal capabilities and any -color flags, COLORTERM variable, and saved .lynxrc settings. -noexec disable local program execution. (DEFAULT) -nofilereferer disable transmissions of Referer headers for file URLs. -nolist disable the link list feature in dumps. -nolog disable mailing of error messages to document owners. -nopause disable forced pauses for statusline messages. -noprint disable print functions. -noredir prevents automatic redirection and prints a message with a link to the new URL. -noreferer disable transmissions of Referer headers. -nosocks disable SOCKS proxy usage by a SOCKSified Lynx. -nostatus disable the retrieval status messages. -number_links force numbering of links. -partial display partial pages while downloading. -pauth=ID:PASSWD set authorization ID and password for a protected proxy server at startup. Be sure to protect any script files which use this switch. -popup toggles handling of single-choice SELECT options via popup windows or as lists of radio buttons. -post_data send form data from stdin using POST method and dump results. -preparsed show HTML source preparsed and reformatted when used with -source or in source view. -print enable print functions. (default) -pseudo_inlines toggles pseudo-ALTs for inlines with no ALT string. -raw toggles default setting of 8-bit character translations or CJK mode for the startup character set. -realm restricts access to URLs in the starting realm. -reload flushes the cache on a proxy server (only the first document affected). -restrictions=[option][,,option]... allows a list of services to be disabled selectively. The following list is printed if no options are specified. all - restricts all options. bookmark - disallow changing the location of the bookmark file. bookmark_exec - disallow execution links via the bookmark file. change_exec_perms - disallow changing the eXecute permission on files (but still allow it for directories) when local file management is enabled. default - same as command line option -anonymous. Disables default services for anonymous users. Currently set to all restricted except for: inside_telnet, outside_telnet, inside_news, inside_ftp, outside_ftp, inside_rlogin, outside_rlogin, jump, mail and goto. Defaults are setable within userdefs.h. dired_support - disallow local file management. disk_save - disallow saving to disk in the download and print menus. download - disallow downloaders in the download menu. editor - disallow editing. exec - disable execution scripts. exec_frozen - disallow the user from changing the local execution option. file_url - disallow using G)oto, served links or bookmarks for file: URLs. goto - disable the 'g' (goto) command. inside_ftp - disallow ftps for people coming from inside your domain (utmp required for selectivity). inside_news - disallow USENET news posting for people coming from inside our domain (utmp required for selectivity). inside_rlogin - disallow rlogins for people coming from inside your domain (utmp required for selectivity). inside_telnet - disallow telnets for people coming from inside your domain (utmp required for selectivity). jump - disable the 'j' (jump) command. multibook - disallow multiple bookmark files. mail - disallow mail. news_post - disallow USENET News posting. options_save - disallow saving options in .lynxrc. outside_ftp - disallow ftps for people coming from outside your domain (utmp required for selectivity). outside_news - disallow USENET news posting for people coming from outside your domain (utmp required for selectivity). outside_rlogin - disallow rlogins for people coming from outside your domain (utmp required for selectivity). outside_telnet - disallow telnets for people coming from outside your domain (utmp required for selectivity). print - disallow most print options. shell - disallow shell escapes and lynxexec or lynxprog G)oto's. suspend - disallow Unix Control-Z suspends with escape to shell. telnet_port - disallow specifying a port in telnet G)oto's. useragent - disallow modifications of the User-Agent header. -resubmit_posts toggles forced resubmissions (no-cache) of forms with method POST when the documents they returned are sought with the PREV_DOC command or from the History List. -rlogin disable recognition of rlogin commands. -selective require .www_browsable files to browse directories. -show_cursor If enabled the cursor will not be hidden in the right hand corner but will instead be positioned at the start of the currently selected link. Show cursor is the default for systems without FANCY_CURSES capabilities. The default configuration can be changed in userdefs.h or lynx.cfg. The command line switch toggles the default. -soft_dquotes toggles emulation of the old Netscape and Mosaic bug which treated '>' as a co-terminator for double-quotes and tags. -source works the same as dump but outputs HTML source instead of formatted text. -stack_dump disable SIGINT cleanup handler -startfile_ok allow non-http startfile and homepage with -validate. -tagsoup initialize parser, using Tag Soup DTD rather than SortaSGML. -telnet disable recognition of telnet commands. -term=TERM tell Lynx what terminal type to assume its talking to. (This may be useful for remote execution, when, for example, Lynx connects to a remote TCP/IP port that starts a script that, in turn, starts another Lynx process.) -tlog toggles use of a Lynx Trace Log for the current session. -trace turns on WWW trace mode. -traversal traverse all http links derived from startfile. When used with -crawl, each link that begins with the same string as startfile is output to a file, intended for indexing. See CRAWL.announce for more information. -underscore toggles use of _underline_ format in dumps. -use_mouse turn on xterm mouse support. Clicking the left mouse button on a link traverses it. Clicking the right mouse button pops back. Click in the first line of a page to scroll up. Click in the last line of a page to scroll down. Lynx must be compiled with ncurses or slang to support this feature. -useragent=Name set alternate Lynx User-Agent header. -validate accept only http URLs (for validation). Complete security restrictions also are implemented. -verbose taggles [LINK], [IMAGE] and [INLINE] comments with filenames of these images. -version print version information. -vikeys enable vi-like key movement. -width=NUMBER number of columns for formatting of dumps, default is 80. 2 COMMANDS o Use Up arrow and Down arrow to scroll through hypertext links. o Right arrow or Return will follow a highlighted hypertext link. o Left Arrow will retreat from a link. o Type "H" or "?" for online help and descriptions of key-stroke commands. o Type "K" for a complete list of the current key-stroke command mappings. 2 ENVIRONMENT In addition to various "standard" environment variables such as HOME, PATH, USER, DISPLAY, TMPDIR, etc, Lynx uti- lizes several Lynx-specific environment variables, if they exist. Others may be created or modified by Lynx to pass data to an external program, or for other reasons. These are listed separately below. See also the sections on SIMULATED CGI SUPPORT and NATIVE LANGUAGE SUPPORT, below. Note: Not all environment variables apply to all types of platforms supported by Lynx, though most do. Feedback on platform dependencies is solicited. Environment Variables Used By Lynx: COLORTERM If set, color capability for the ter- minal is forced on at startup time. The actual value assigned to the vari- able is ignored. This variable is only meaningful if Lynx was built using the slang screen-handling library. LYNX_CFG This variable, if set, will override the default location and name of the global configuration file (normally, lynx.cfg) that was defined by the LYNX_CFG_FILE constant in the userdefs.h file, during installation. See the userdefs.h file for more information. LYNX_LSS This variable, if set, specifies the location of the default Lynx character style sheet file. [Currently only meaningful if Lynx was built using experimental color style support.] LYNX_SAVE_SPACE This variable, if set, will override the default path prefix for files saved to disk that is defined in the lynx.cfg SAVE_SPACE: statement. See the lynx.cfg file for more informa- tion. LYNX_TEMP_SPACE This variable, if set, will override the default path prefix for temporary files that was defined during instal- lation, as well as any value that may be assigned to the TMPDIR variable. MAIL This variable specifies the default inbox Lynx will check for new mail, if such checking is enabled in the lynx.cfg file. NEWS_ORGANIZATION This variable, if set, provides the string used in the Organization: header of USENET news postings. It will override the setting of the ORGA- NIZATION environment variable, if it is also set (and, on UNIX, the con- tents of an /etc/organization file, if present). NNTPSERVER If set, this variable specifies the default NNTP server that will be used for USENET news reading and posting with Lynx, via news: URL's. ORGANIZATION This variable, if set, provides the string used in the Organization: header of USENET news postings. On UNIX, it will override the contents of an /etc/organization file, if present. PROTOCOL_proxy Lynx supports the use of proxy servers that can act as firewall gateways and caching servers. They are preferable to the older gateway servers (see WWW_access_GATEWAY, below). Each pro- tocol used by Lynx, (http, ftp, gopher, etc), can be mapped separately by setting environment variables of the form PROTOCOL_proxy (literally: http_proxy, ftp_proxy, gopher_proxy, etc), to "http://some.server.dom:port/". See Lynx Users Guide for additional details and examples. WWW_access_GATEWAY Lynx still supports use of gateway servers, with the servers specified via "WWW_access_GATEWAY" variables (where "access" is lower case and can be "http", "ftp", "gopher" or "wais"), however most gateway servers have been discontinued. Note that you do not include a terminal '/' for gateways, but do for proxies specified by PROTO- COL_proxy environment variables. See Lynx Users Guide for details. WWW_HOME This variable, if set, will override the default startup URL specified in any of the Lynx configuration files. Environment Variables Set or Modified By Lynx: LYNX_PRINT_DATE This variable is set by the Lynx p(rint) function, to the Date: string seen in the document's "Information about" page (= cmd), if any. It is created for use by an external pro- gram, as defined in a lynx.cfg PRINTER: definition statement. If the field does not exist for the document, the variable is set to a null string under UNIX, or "No Date" under VMS. LYNX_PRINT_LASTMOD This variable is set by the Lynx p(rint) function, to the Last Mod: string seen in the document's "Infor- mation about" page (= cmd), if any. It is created for use by an external program, as defined in a lynx.cfg PRINTER: definition statement. If the field does not exist for the document, the variable is set to a null string under UNIX, or "No LastMod" under VMS. LYNX_PRINT_TITLE This variable is set by the Lynx p(rint) function, to the Linkname: string seen in the document's "Infor- mation about" page (= cmd), if any. It is created for use by an external program, as defined in a lynx.cfg PRINTER: definition statement. If the field does not exist for the document, the variable is set to a null string under UNIX, or "No Title" under VMS. LYNX_PRINT_URL This variable is set by the Lynx p(rint) function, to the URL: string seen in the document's "Information about" page (= cmd), if any. It is created for use by an external pro- gram, as defined in a lynx.cfg PRINTER: definition statement. If the field does not exist for the document, the variable is set to a null string under UNIX, or "No URL" under VMS. LYNX_VERSION This variable is always set by Lynx, and may be used by an external program to determine if it was invoked by Lynx. See also the comments in the distribution's sample mailcap file, for notes on usage in such a file. TERM Normally, this variable is used by Lynx to determine the terminal type being used to invoke Lynx. If, how- ever, it is unset at startup time (or has the value "unknown"), or if the -term command-line option is used (see OPTIONS section above), Lynx will set or modify its value to the user speci- fied terminal type (for the Lynx exe- cution environment). Note: If set/modified by Lynx, the values of the LINES and/or COLUMNS environment variables may also be changed. 2 SIMULATED CGI SUPPORT If built with the cgi-links option enabled, Lynx allows access to a cgi script directly without the need for an http daemon. When executing such "lynxcgi scripts" (if enabled), the following variables may be set for simulating a CGI envi- ronment: CONTENT_LENGTH CONTENT_TYPE DOCUMENT_ROOT HTTP_ACCEPT_CHARSET HTTP_ACCEPT_LANGUAGE HTTP_USER_AGENT PATH_INFO PATH_TRANSLATED QUERY_STRING REMOTE_ADDR REMOTE_HOST REQUEST_METHOD SERVER_SOFTWARE Other environment variables are not inherited by the script, unless they are provided via a LYNXCGI_ENVIRONMENT statement in the configuration file. See the lynx.cfg file, and the (draft) CGI 1.1 Specification for the definition and usage of these variables. The CGI Specification, and other associated documentation, should be consulted for general information on CGI script programming. 2 NATIVE LANGUAGE SUPPORT If configured and installed with Native Language Support, Lynx will display status and other messages in your local language. See the file ABOUT_NLS in the source distribu- tion, or at your local GNU site, for more information about internationalization. The following environment variables may be used to alter default settings: LANG This variable, if set, will override the default message language. It is an ISO 639 two-letter code identifying the language. Language codes are NOT the same as the country codes given in ISO 3166. LANGUAGE This variable, if set, will override the default message language. This is a GNU extension that has higher prior- ity for setting the message catalog than LANG or LC_ALL. LC_ALL and LC_MESSAGES These variables, if set, specify the notion of native language formatting style. They are POSIXly correct. LINGUAS This variable, if set prior to config- uration, limits the installed lan- guages to specific values. It is a space-separated list of two-letter codes. Currently, it is hard-coded to a wish list. NLSPATH This variable, if set, is used as the path prefix for message catalogs. 2 NOTES This is the Lynx v2.8.1 Release If you wish to contribute to the further development of Lynx, subscribe to our mailing list. Send email to with "subscribe lynx-dev" as the only line in the body of your message. Send bug reports, comments, suggestions to after subscribing. Unsubscribe by sending email to with "unsubscribe lynx-dev" as the only line in the body of your message. Do not send the unsubscribe message to the lynx-dev list, itself. 2 SEE ALSO catgets(3), curses(3), environ(7), execve(2), ftp(1), gettext(GNU), localeconv(3), ncurses(3), setlocale(3), slang(?), termcap(5), terminfo(5), wget(GNU) Note that man page availability and section numbering is somewhat platform dependent, and may vary from the above references. A section shown as (GNU), is intended to denote that the topic may be available via an info page, instead of a man page (ie, try "info subject", rather than "man subject"). A section shown as (?) denotes that documentation on the topic exists, but is not part of an established documenta- tion retrieval system (see the distribution files associ- ated with the topic, or contact your System Administrator for further information). 2 ACKNOWLEDGMENTS Lynx has incorporated code from a variety of sources along the way. The earliest versions of Lynx included code from Earl Fogel of Computing Services at the University of Saskatchewan, who implemented HYPERREZ in the Unix environment. HYPERREZ was developed by Niel Larson of Think.com and served as the model for the early versions of Lynx. Those versions also incorporated libraries from the Unix Gopher clients developed at the University of Minnesota, and the later versions of Lynx rely on the WWW client library code developed by Tim Berners-Lee and the WWW community. Also a special thanks to Foteos Macrides who ported much of Lynx to VMS and did or organized most of its development since the departures of Lou Montulli and Garrett Blythe from the University of Kansas in the summer of 1994 through the release of v2.7.2, and to everyone on the net who has contributed to Lynx's development either directly (through patches, comments or bug reports) or indirectly (through inspiration and development of other systems). 2 AUTHORS Lou Montulli, Garrett Blythe, Craig Lavender, Michael Grobe, Charles Rezac Academic Computing Services University of Kansas Lawrence, Kansas 66047 Foteos Macrides Worcester Foundation for Biomedical Research Shrewsbury, Massachusetts 01545