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diff --git a/src/civetweb/docs/UserManual.md b/src/civetweb/docs/UserManual.md new file mode 100644 index 00000000..3acf4927 --- /dev/null +++ b/src/civetweb/docs/UserManual.md @@ -0,0 +1,814 @@ + +Overview +===== + +Civetweb is small and easy to use web server. +It may be embedded into C/C++ host applications or used as a stand-alone +server. See `Embedding.md` for information on embedding civetweb into +host applications. + +The stand-alone server is self-contained, and does not require any external +software to run. Some Windows users may need to install the +[Visual C++ Redistributable](http://www.microsoft.com/en-us/download/details.aspx?id=30679). + +Installation +---- + +On Windows, UNIX and Mac, the civetweb stand-alone executable may be started +from the command line. +Running `civetweb` in a terminal, optionally followed by configuration parameters +(`civetweb [OPTIONS]`) or a configuration file name (`civetweb [config_file_name]`), +starts the web server. + +For UNIX and Mac, civetweb does not detach from the terminal. +Pressing `Ctrl-C` keys will stop the server. + +On Windows, civetweb iconifies itself to the system tray icon when started. +Right-click on the icon pops up a menu, where it is possible to stop +civetweb, or configure it, or install it as Windows service. + +When started without options, the server exposes the local directory at +[http](http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol) port 8080. +Thus, the easiest way to share a folder on Windows is to copy `civetweb.exe` +to this folder, double-click the exe, and launch a browser at +[http://localhost:8080](http://localhost:8080). Note that 'localhost' should +be changed to a machine's name if a folder is accessed from other computer. + +When started, civetweb first searches for the configuration file. +If configuration file is specified explicitly in the command line, i.e. +`civetweb path_to_config_file`, then specified configuration file is used. +Otherwise, civetweb would search for file `civetweb.conf` in the same directory +the executable is located, and use it. This configuration file is optional. + +The configuration file is a sequence of lines, each line containing one +command line argument name and the corresponding value. +Empty lines, and lines beginning with `#`, are ignored. +Here is the example of `civetweb.conf` file: + + document_root c:\www + listening_ports 80,443s + ssl_certificate c:\civetweb\ssl_cert.pem + +When a configuration file is used, additional command line arguments may +override the configuration file settings. +All command line arguments must start with `-`. + +For example: The above `civetweb.conf` file is used, and civetweb started as +`civetweb -document_root D:\web`. Then the `D:\web` directory will be served +as document root, because command line options take priority over the +configuration file. The configuration options section below provides a good +overview of the Civetweb features. + +Note that configuration options on the command line must start with `-`, +but their names are the same as in the config file. All option names are +listed in the next section. Thus, the following two setups are equivalent: + + # Using command line arguments + $ civetweb -listening_ports 1234 -document_root /var/www + + # Using config file + $ cat civetweb.conf + listening_ports 1234 + document_root /var/www + $ civetweb + +Civetweb can also be used to modify `.htpasswd` passwords files: + + civetweb -A <htpasswd_file> <realm> <user> <passwd> + +Unlike other web servers, civetweb does not require CGI scripts to be located +in a special directory. CGI scripts can be anywhere. CGI (and SSI) files are +recognized by the file name pattern. Civetweb uses shell-like glob +patterns. Pattern match starts at the beginning of the string, so essentially +patterns are prefix patterns. Syntax is as follows: + + ** Matches everything + * Matches everything but slash character, '/' + ? Matches any character + $ Matches the end of the string + | Matches if pattern on the left side or the right side matches. + +All other characters in the pattern match themselves. Examples: + + **.cgi$ Any string that ends with .cgi + /foo Any string that begins with /foo + **a$|**b$ Any string that ends with a or b + +# Configuration Options + +Below is a list of configuration options understood by Civetweb. +Every option is followed by it's default value. If a default value is not +present, then the default is empty. + +### cgi\_pattern `**.cgi$|**.pl$|**.php$` +All files that match `cgi_pattern` are treated as CGI files. Default pattern +allows CGI files be anywhere. To restrict CGIs to a certain directory, +use `/path/to/cgi-bin/**.cgi` as pattern. Note that the full file path is +matched against the pattern, not the URI. + +### cgi\_environment +Extra environment variables to be passed to the CGI script in +addition to standard ones. The list must be comma-separated list +of name=value pairs, like this: `VARIABLE1=VALUE1,VARIABLE2=VALUE2`. + +### put\_delete\_auth\_file +Passwords file for PUT and DELETE requests. Without password file, it will not +be possible to, PUT new files to the server or DELETE existing ones. PUT and +DELETE requests might still be handled by Lua scripts and CGI paged. + +### cgi\_interpreter +Path to an executable to use as CGI interpreter for __all__ CGI scripts +regardless of the script file extension. If this option is not set (which is +the default), Civetweb looks at first line of a CGI script, +[shebang line](http://en.wikipedia.org/wiki/Shebang_(Unix\)), for an +interpreter (not only on Linux and Mac but also for Windows). + +For example, if both PHP and Perl CGIs are used, then +`#!/path/to/php-cgi.exe` and `#!/path/to/perl.exe` must be first lines of the +respective CGI scripts. Note that paths should be either full file paths, +or file paths relative to the current working directory of the civetweb +server. If civetweb is started by mouse double-click on Windows, the current +working directory is the directory where the civetweb executable is located. + +If all CGIs use the same interpreter, for example they are all PHP, it is +more efficient to set `cgi_interpreter` to the path to `php-cgi.exe`. +The shebang line in the CGI scripts can be omitted in this case. +Note that PHP scripts must use `php-cgi.exe` as executable, not `php.exe`. + +### protect\_uri +Comma separated list of URI=PATH pairs, specifying that given +URIs must be protected with password files specified by PATH. +All Paths must be full file paths. + +### authentication\_domain `mydomain.com` +Authorization realm used for HTTP digest authentication. This domain is +used in the encoding of the `.htpasswd` authorization files as well. +Changing the domain retroactively will render the existing passwords useless. + +### enable\_auth\_domain\_check `yes` +When using absolute URLs, verify the host is identical to the authentication\_domain. If enabled, requests to absolute URLs will only be processed +if they are directed to the domain. If disabled, absolute URLs to any host +will be accepted. + +### ssi\_pattern `**.shtml$|**.shtm$` +All files that match `ssi_pattern` are treated as Server Side Includes (SSI). + +SSI is a simple interpreted server-side scripting language which is most +commonly used to include the contents of another file into a web page. +It can be useful when it is desirable to include a common piece +of code throughout a website, for example, headers and footers. + +In order for a webpage to recognize an SSI-enabled HTML file, the filename +should end with a special extension, by default the extension should be +either `.shtml` or `.shtm`. These extentions may be changed using the +`ssi_pattern` option. + +Unknown SSI directives are silently ignored by civetweb. Currently, two SSI +directives are supported, `<!--#include ...>` and +`<!--#exec "command">`. Note that the `<!--#include ...>` directive supports +three path specifications: + + <!--#include virtual="path"> Path is relative to web server root + <!--#include abspath="path"> Path is absolute or relative to + web server working dir + <!--#include file="path">, Path is relative to current document + <!--#include "path"> + +The `include` directive may be used to include the contents of a file or the +result of running a CGI script. The `exec` directive is used to execute a +command on a server, and show the output that would have been printed to +stdout (the terminal window) otherwise. Example: + + <!--#exec "ls -l" --> + +For more information on Server Side Includes, take a look at the Wikipedia: +[Server Side Includes](http://en.wikipedia.org/wiki/Server_Side_Includes) + +### throttle +Limit download speed for clients. `throttle` is a comma-separated +list of key=value pairs, where key could be: + + * limit speed for all connections + x.x.x.x/mask limit speed for specified subnet + uri_prefix_pattern limit speed for given URIs + +The value is a floating-point number of bytes per second, optionally +followed by a `k` or `m` character, meaning kilobytes and +megabytes respectively. A limit of 0 means unlimited rate. The +last matching rule wins. Examples: + + *=1k,10.0.0.0/8=0 limit all accesses to 1 kilobyte per second, + but give connections the from 10.0.0.0/8 subnet + unlimited speed + + /downloads/=5k limit accesses to all URIs in `/downloads/` to + 5 kilobytes per second. All other accesses are unlimited + +### access\_log\_file +Path to a file for access logs. Either full path, or relative to the current +working directory. If absent (default), then accesses are not logged. + +### enable\_directory\_listing `yes` +Enable directory listing, either `yes` or `no`. + +### error\_log\_file +Path to a file for error logs. Either full path, or relative to the current +working directory. If absent (default), then errors are not logged. + +### global\_auth\_file +Path to a global passwords file, either full path or relative to the current +working directory. If set, per-directory `.htpasswd` files are ignored, +and all requests are authorized against that file. + +The file has to include the realm set through `authentication_domain` and the +password in digest format: + + user:realm:digest + test:test.com:ce0220efc2dd2fad6185e1f1af5a4327 + +Password files may be generated using `civetweb -A` as explained above, or +online tools e.g. [this generator](http://www.askapache.com/online-tools/htpasswd-generator). + +### index\_files `index.xhtml,index.html,index.htm,index.cgi,index.shtml,index.php` +Comma-separated list of files to be treated as directory index files. +If more than one matching file is present in a directory, the one listed to the left +is used as a directory index. + +In case built-in Lua support has been enabled, `index.lp,index.lsp,index.lua` +are additional default index files, ordered before `index.cgi`. + +### enable\_keep\_alive `no` +Enable connection keep alive, either `yes` or `no`. + +Allows clients to reuse TCP connection for subsequent HTTP requests, +which improves performance. +For this to work when using request handlers it is important to add the +correct Content-Length HTTP header for each request. If this is forgotten the +client will time out. + +Note: If you set keep\_alive to `yes`, you should set keep\_alive\_timeout\_ms +to some value > 0 (e.g. 500). If you set keep\_alive to `no`, you should set +keep\_alive\_timeout\_ms to 0. Currently, this is done as a default value, +but this configuration is redundant. In a future version, the keep\_alive +configuration option might be removed and automatically set to `yes` if +a timeout > 0 is set. + +### access\_control\_list +An Access Control List (ACL) allows restrictions to be put on the list of IP +addresses which have access to the web server. In the case of the Civetweb +web server, the ACL is a comma separated list of IP subnets, where each +subnet is pre-pended by either a `-` or a `+` sign. A plus sign means allow, +where a minus sign means deny. If a subnet mask is omitted, such as `-1.2.3.4`, +this means to deny only that single IP address. + +Subnet masks may vary from 0 to 32, inclusive. The default setting is to allow +all accesses. On each request the full list is traversed, and +the last match wins. Examples: + + -0.0.0.0/0,+192.168/16 deny all accesses, only allow 192.168/16 subnet + +To learn more about subnet masks, see the +[Wikipedia page on Subnetwork](http://en.wikipedia.org/wiki/Subnetwork). + +### extra\_mime\_types +Extra mime types, in tha form `extension1=type1,exten-sion2=type2,...`. +See the [Wikipedia page on Internet media types](http://en.wikipedia.org/wiki/Internet_media_type). +Extension must include a leading dot. Example: +`.cpp=plain/text,.java=plain/text` + +### listening\_ports `8080` +Comma-separated list of ports to listen on. If the port is SSL, a +letter `s` must be appended, for example, `80,443s` will open +port 80 and port 443, and connections on port 443 will be SSL-ed. +For non-SSL ports, it is allowed to append letter `r`, meaning 'redirect'. +Redirect ports will redirect all their traffic to the first configured +SSL port. For example, if `listening_ports` is `80r,443s`, then all +HTTP traffic coming at port 80 will be redirected to HTTPS port 443. + +It is possible to specify an IP address to bind to. In this case, +an IP address and a colon must be pre-pended to the port number. +For example, to bind to a loopback interface on port 80 and to +all interfaces on HTTPS port 443, use `127.0.0.1:80,443s`. + +If the server is built with IPv6 support, `[::]:8080` can be used to +listen to IPv6 connections to port 8080. IPv6 addresses of network +interfaces can be specified as well, +e.g. `[::1]:8080` for the IPv6 loopback interface. + +[::]:80 will bind to port 80 IPv6 only. In order to use port 80 for +all interfaces, both IPv4 and IPv6, use either the configuration +`80,[::]:80` (create one socket for IPv4 and one for IPv6 only), +or `+80` (create one socket for both, IPv4 and IPv6). +The `+`-notation to use IPv4 and IPv6 will only work in no network +interface is specified. Depending on your operating system version +and IPv6 network environment, some configurations might not work +as expected, so you have to test to find the configuration most +suitable for your needs. In case `+80` does not work for your +environment, you need to use `80,[::]:80`. + +It is possible to use network interface addresses (e.g., `192.0.2.3:80`, +`[2001:0db8::1234]:80`). To get a list of available network interface +addresses, use `ipconfig` (in a `cmd` window in Windows) or `ifconfig` +(in a Linux shell). +Alternatively, you could use the hostname for an interface. Check the +hosts file of your operating system for a proper hostname +(for Windows, usually found in C:\Windows\System32\drivers\etc\, +for most Linux distributions: /etc/hosts). E.g., to bind the IPv6 +local host, you could use `ip6-localhost:80`. This translates to +`[::1]:80`. Beside the hosts file, there are several other name +resolution services. Using your hostname might bind you to the +localhost or an external interface. You could also try `hostname.local`, +if the proper network services are installed (Zeroconf, mDNS, Bonjour, +Avahi). When using a hostname, you need to test in your particular network +environment - in some cases, you might need to resort to a fixed IP address. + +### document\_root `.` +A directory to serve. By default, the current working directory is served. +The current directory is commonly referenced as dot (`.`). +It is recommended to use an absolute path for document\_root, in order to +avoid accidentally serving the wrong directory. + +### ssl\_certificate +Path to the SSL certificate file. This option is only required when at least +one of the `listening\_ports` is SSL. The file must be in PEM format, +and it must have both, private key and certificate, see for example +[ssl_cert.pem](https://github.com/civetweb/civetweb/blob/master/resources/ssl_cert.pem) +A description how to create a certificate can be found in doc/OpenSSL.md + +### num\_threads `50` +Number of worker threads. Civetweb handles each incoming connection in a +separate thread. Therefore, the value of this option is effectively the number +of concurrent HTTP connections Civetweb can handle. + +### run\_as\_user +Switch to given user credentials after startup. Usually, this option is +required when civetweb needs to bind on privileged ports on UNIX. To do +that, civetweb needs to be started as root. From a security point of view, +running as root is not advisable, therefore this option can be used to drop +privileges. Example: + + civetweb -listening_ports 80 -run_as_user webserver + +### url\_rewrite\_patterns +Comma-separated list of URL rewrites in the form of +`uri_pattern=file_or_directory_path`. When Civetweb receives any request, +it constructs the file name to show by combining `document_root` and the URI. +However, if the rewrite option is used and `uri_pattern` matches the +requested URI, then `document_root` is ignored. Instead, +`file_or_directory_path` is used, which should be a full path name or +a path relative to the web server's current working directory. Note that +`uri_pattern`, as all civetweb patterns, is a prefix pattern. + +This makes it possible to serve many directories outside from `document_root`, +redirect all requests to scripts, and do other tricky things. For example, +to redirect all accesses to `.doc` files to a special script, do: + + civetweb -url_rewrite_patterns **.doc$=/path/to/cgi-bin/handle_doc.cgi + +Or, to imitate support for user home directories, do: + + civetweb -url_rewrite_patterns /~joe/=/home/joe/,/~bill=/home/bill/ + +### hide\_files\_patterns +A pattern for the files to hide. Files that match the pattern will not +show up in directory listing and return `404 Not Found` if requested. Pattern +must be for a file name only, not including directory names. Example: + + civetweb -hide_files_patterns secret.txt|**.hide + +Note: hide\_file\_patterns uses the pattern described above. If you want to +hide all files with a certain extension, make sure to use **.extension +(not just *.extension). + +### request\_timeout\_ms `30000` +Timeout for network read and network write operations, in milliseconds. +If a client intends to keep long-running connection, either increase this +value or (better) use keep-alive messages. + +### keep\_alive\_timeout\_ms `500` or `0` +Idle timeout between two requests in one keep-alive connection. +If keep alive is enabled, multiple requests using the same connection +are possible. This reduces the overhead for opening and closing connections +when loading several resources from one server, but it also blocks one port +and one thread at the server during the lifetime of this connection. +Unfortunately, browsers do not close the keep-alive connection after loading +all resources required to show a website. +The server closes a keep-alive connection, if there is no additional request +from the client during this timeout. + +Note: if enable\_keep\_alive is set to `no` the value of +keep\_alive\_timeout\_ms should be set to `0`, if enable\_keep\_alive is set +to `yes`, the value of keep\_alive\_timeout\_ms must be >0. +Currently keep\_alive\_timeout\_ms is ignored if enable\_keep\_alive is no, +but future versions my drop the enable\_keep\_alive configuration value and +automatically use keep-alive if keep\_alive\_timeout\_ms is not 0. + +### linger\_timeout\_ms +Set TCP socket linger timeout before closing sockets (SO\_LINGER option). +The configured value is a timeout in milliseconds. Setting the value to 0 +will yield in abortive close (if the socket is closed from the server side). +Setting the value to -1 will turn off linger. +If the value is not set (or set to -2), CivetWeb will not set the linger +option at all. + +Note: For consistency with other timeouts, the value is configured in +milliseconds. However, the TCP socket layer usually only offers a timeout in +seconds, so the value should be an integer multiple of 1000. + +### lua\_preload\_file +This configuration option can be used to specify a Lua script file, which +is executed before the actual web page script (Lua script, Lua server page +or Lua websocket). It can be used to modify the Lua environment of all web +page scripts, e.g., by loading additional libraries or defining functions +required by all scripts. +It may be used to achieve backward compatibility by defining obsolete +functions as well. + +### lua\_script\_pattern `"**.lua$` +A pattern for files that are interpreted as Lua scripts by the server. +In contrast to Lua server pages, Lua scripts use plain Lua syntax. +An example can be found in the test directory. + +### lua\_server\_page\_pattern `**.lp$|**.lsp$` +Files matching this pattern are treated as Lua server pages. +In contrast to Lua scripts, the content of a Lua server pages is delivered +directly to the client. Lua script parts are delimited from the standard +content by including them between <? and ?> tags. +An example can be found in the test directory. + +### lua\_background\_script +Experimental feature, and subject to change. +Run a Lua script in the background, independent from any connection. +The script is started before network access to the server is available. +It can be used to prepare the document root (e.g., update files, compress +files, ...), check for external resources, remove old log files, etc. + +The Lua state remains open until the server is stopped. +In the future, some callback functions will be available to notify the +script on changes of the server state. See example lua script : +[background.lua](https://github.com/civetweb/civetweb/blob/master/test/background.lua). + +Additional functions available in background script : +sleep, root path, script name, isterminated + +### lua\_background\_script\_params `param1=1,param2=2` +Can add dynamic parameters to background script. +Parameters mapped to global 'mg' table 'params' field. + +### websocket\_root +In case civetweb is built with Lua and websocket support, Lua scripts may +be used for websockets as well. Since websockets use a different URL scheme +(ws, wss) than other http pages (http, https), the Lua scripts used for +websockets may also be served from a different directory. By default, +the document_root is used as websocket_root as well. + + +### access\_control\_allow\_origin `*` +Access-Control-Allow-Origin header field, used for cross-origin resource +sharing (CORS). +See the [Wikipedia page on CORS](http://en.wikipedia.org/wiki/Cross-origin_resource_sharing). + + +### access\_control\_allow\_methods `*` +Access-Control-Allow-Methods header field, used for cross-origin resource +sharing (CORS) pre-flight requests. +See the [Wikipedia page on CORS](http://en.wikipedia.org/wiki/Cross-origin_resource_sharing). + +If set to an empty string, pre-flights will not be supported directly by the server, +but scripts may still support pre-flights by handling the OPTIONS method properly. +If set to "*", the pre-flight will allow whatever method has been requested. +If set to a comma separated list of valid HTTP methods, the pre-flight will return +exactly this list as allowed method. +If set in any other way, the result is unspecified. + + +### access\_control\_allow\_headers `*` +Access-Control-Allow-Headers header field, used for cross-origin resource +sharing (CORS) pre-flight requests. +See the [Wikipedia page on CORS](http://en.wikipedia.org/wiki/Cross-origin_resource_sharing). + +If set to an empty string, pre-flights will not allow additional headers. +If set to "*", the pre-flight will allow whatever headers have been requested. +If set to a comma separated list of valid HTTP headers, the pre-flight will return +exactly this list as allowed headers. +If set in any other way, the result is unspecified. + + +### error\_pages +This option may be used to specify a directory for user defined error pages. +The error pages may be specified for an individual http status code (e.g., +404 - page requested by the client not found), a group of http status codes +(e.g., 4xx - all client errors) or all errors. The corresponding error pages +must be called error404.ext, error4xx.ext or error.ext, whereas the file +extention may be one of the extentions specified for the index_files option. +See the [Wikipedia page on HTTP status codes](http://en.wikipedia.org/wiki/HTTP_status_code). + +### tcp\_nodelay `0` +Enable TCP_NODELAY socket option on client connections. + +If set the socket option will disable Nagle's algorithm on the connection +which means that packets will be sent as soon as possible instead of waiting +for a full buffer or timeout to occur. + + 0 Keep the default: Nagel's algorithm enabled + 1 Disable Nagel's algorithm for all sockets + +### static\_file\_max\_age `3600` +Set the maximum time (in seconds) a cache may store a static files. + +This option will set the `Cache-Control: max-age` value for static files. +Dynamically generated content, i.e., content created by a script or callback, +must send cache control headers by themselfes. + +A value >0 corresponds to a maximum allowed caching time in seconds. +This value should not exceed one year (RFC 2616, Section 14.21). +A value of 0 will send "do not cache" headers for all static files. +For values <0 and values >31622400, the behavior is undefined. + +### strict\_transport\_security\_max\_age + +Set the `Strict-Transport-Security` header, and set the `max-age` value. +This instructs web browsers to interact with the server only using HTTPS, +never by HTTP. If set, it will be sent for every request handled directly +by the server, except scripts (CGI, Lua, ..) and callbacks. They must +send HTTP headers on their own. + +The time is specified in seconds. If this configuration is not set, +or set to -1, no `Strict-Transport-Security` header will be sent. +For values <-1 and values >31622400, the behavior is undefined. + +### decode\_url `yes` +URL encoded request strings are decoded in the server, unless it is disabled +by setting this option to `no`. + +### ssl\_verify\_peer `no` +Enable client's certificate verification by the server. + +### ssl\_ca\_path +Name of a directory containing trusted CA certificates. Each file in the +directory must contain only a single CA certificate. The files must be named +by the subject name’s hash and an extension of “.0”. If there is more than one +certificate with the same subject name they should have extensions ".0", ".1", +".2" and so on respectively. + +### ssl\_ca\_file +Path to a .pem file containing trusted certificates. The file may contain +more than one certificate. + +### ssl\_verify\_depth `9` +Sets maximum depth of certificate chain. If client's certificate chain is longer +than the depth set here connection is refused. + +### ssl\_default\_verify\_paths `yes` +Loads default trusted certificates locations set at openssl compile time. + +### ssl\_cipher\_list +List of ciphers to present to the client. Entries should be separated by +colons, commas or spaces. + + ALL All available ciphers + ALL:!eNULL All ciphers excluding NULL ciphers + AES128:!MD5 AES 128 with digests other than MD5 + +See [this entry](https://www.openssl.org/docs/manmaster/apps/ciphers.html) in +OpenSSL documentation for full list of options and additional examples. + +### ssl\_protocol\_version `0` +Sets the minimal accepted version of SSL/TLS protocol according to the table: + +Protocols | Value +------------ | ------------- +SSL2+SSL3+TLS1.0+TLS1.1+TLS1.2 | 0 +SSL3+TLS1.0+TLS1.1+TLS1.2 | 1 +TLS1.0+TLS1.1+TLS1.2 | 2 +TLS1.1+TLS1.2 | 3 +TLS1.2 | 4 + +### ssl\_short\_trust `no` +Enables the use of short lived certificates. This will allow for the certificates +and keys specified in `ssl_certificate`, `ssl_ca_file` and `ssl_ca_path` to be +exchanged and reloaded while the server is running. + +In an automated environment it is advised to first write the new pem file to +a different filename and then to rename it to the configured pem file name to +increase performance while swapping the certificate. + +Disk IO performance can be improved when keeping the certificates and keys stored +on a tmpfs (linux) on a system with very high throughput. + +### allow\_sendfile\_call `yes` +This option can be used to enable or disable the use of the Linux `sendfile` system call. It is only available for Linux systems and only affecting HTTP (not HTTPS) connections if `throttle` is not enabled. While using the `sendfile` call will lead to a performance boost for HTTP connections, this call may be broken for some file systems and some operating system versions. + +### case\_sensitive `no` +This option can be uset to enable case URLs for Windows servers. It is only available for Windows systems. Windows file systems are not case sensitive, but they still store the file name including case. If this option is set to `yes`, the comparison for URIs and Windows file names will be case sensitive. + +### allow\_index\_script\_resource `no` +Index scripts (like `index.cgi` or `index.lua`) may have script handled resources. + +It this feature is activated, that /some/path/file.ext might be handled by: + 1. /some/path/file.ext (with PATH\_INFO='/', if ext = cgi) + 2. /some/path/index.lua with mg.request\_info.path\_info='/file.ext' + 3. /some/path/index.cgi with PATH\_INFO='/file.ext' + 4. /some/path/index.php with PATH\_INFO='/file.ext' + 5. /some/index.lua with mg.request\_info.path\_info=='/path/file.ext' + 6. /some/index.cgi with PATH\_INFO='/path/file.ext' + 7. /some/index.php with PATH\_INFO='/path/file.ext' + 8. /index.lua with mg.request\_info.path\_info=='/some/path/file.ext' + 9. /index.cgi with PATH\_INFO='/some/path/file.ext' + 10. /index.php with PATH\_INFO='/some/path/file.ext' + +Note: This example is valid, if the default configuration values for `index_files`, `cgi_pattern` and `lua_script_pattern` are used, and the server is built with CGI and Lua support enabled. + +If this feature is not activated, only the first file (/some/path/file.cgi) will be accepted. + +Note: This parameter affects only index scripts. A path like /here/script.cgi/handle/this.ext will call /here/script.cgi with PATH\_INFO='/handle/this.ext', no matter if this option is set to `yes` or `no`. + +This feature can be used to completely hide the script extension from the URL. + +### additional\_header +Send additional HTTP response header line for every request. +The full header line including key and value must be specified, excluding the carriage return line feed. + +Example (used as command line option): +`-additional_header "X-Frame-Options: SAMEORIGIN"` + +This option can be specified multiple times. All specified header lines will be sent. + +# Lua Scripts and Lua Server Pages +Pre-built Windows and Mac civetweb binaries have built-in Lua scripting +support as well as support for Lua Server Pages. + +Lua scripts (default extension: *.lua) use plain Lua syntax. +The body of the script file is not sent directly to the client, +the Lua script must send header and content of the web page by calling +the function mg.write(text). + +Lua Server Pages (default extensions: *.lsp, *.lp) are html pages containing +script elements similar to PHP, using the Lua programming language instead of +PHP. Lua script elements must be enclosed in `<? ?>` blocks, and can appear +anywhere on the page. Furthermore, Lua Server Pages offer the opportunity to +insert the content of a variable by enclosing the Lua variable name in +`<?= ?>` blocks, similar to PHP. +For example, to print the current weekday name and the URI of the current +page, one can write: + + <p> + <span>Today is:</span> + <? mg.write(os.date("%A")) ?> + </p> + <p> + URI is <?=mg.request_info.uri?> + </p> + +Lua is known for it's speed and small size. Civetweb currently uses Lua +version 5.2.4. The documentation for it can be found in the +[Lua 5.2 reference manual](http://www.lua.org/manual/5.2/). + + +Note that this example uses function `mg.write()`, which sends data to the +web client. Using `mg.write()` is the way to generate web content from inside +Lua code. In addition to `mg.write()`, all standard Lua library functions +are accessible from the Lua code (please check the reference manual for +details). Lua functions working on files (e.g., `io.open`) use a path +relative to the working path of the civetweb process. The web server content +is located in the path `mg.document_root`. +Information on the request is available in the `mg.request_info` +object, like the request method, all HTTP headers, etcetera. + +[page2.lua](https://github.com/civetweb/civetweb/blob/master/test/page2.lua) +is an example for a plain Lua script. + +[page2.lp](https://github.com/civetweb/civetweb/blob/master/test/page2.lp) +is an example for a Lua Server Page. + +Both examples show the content of the `mg.request_info` object as the page +content. Please refer to `struct mg_request_info` definition in +[civetweb.h](https://github.com/civetweb/civetweb/blob/master/include/civetweb.h) +to see additional information on the elements of the `mg.request_info` object. + +Civetweb also provides access to the [SQlite3 database](http://www.sqlite.org/) +through the [LuaSQLite3 interface](http://lua.sqlite.org/index.cgi/doc/tip/doc/lsqlite3.wiki) +in Lua. Examples are given in +[page.lua](https://github.com/civetweb/civetweb/blob/master/test/page.lua) and +[page.lp](https://github.com/civetweb/civetweb/blob/master/test/page.lp). + + +Civetweb exports the following functions to Lua: + +mg (table): + + mg.read() -- reads a chunk from POST data, returns it as a string + mg.write(str) -- writes string to the client + mg.include(filename, [pathtype]) -- include another Lua Page file (Lua Pages only) + -- pathtype can be "abs", "rel"/"file" or "virt[ual]" + -- like defined for SSI #include + mg.redirect(uri) -- internal redirect to a given URI + mg.onerror(msg) -- error handler, can be overridden + mg.version -- a string that holds Civetweb version + mg.document_root -- a string that holds the document root directory + mg.auth_domain -- a string that holds the HTTP authentication domain + mg.get_var(str, varname) -- extract variable from (query) string + mg.get_cookie(str, cookie) -- extract cookie from a string + mg.get_mime_type(filename) -- get MIME type of a file + mg.get_info(infotype) -- get server status information + mg.send_file(filename) -- send a file, including MIME type + mg.url_encode(str) -- URL encode a string + mg.url_decode(str, [form]) -- URL decode a string. If form=true, replace + by space. + mg.base64_encode(str) -- BASE64 encode a string + mg.base64_decode(str) -- BASE64 decode a string + mg.md5(str) -- return the MD5 hash of a string + mg.keep_alive(bool) -- allow/forbid to use http keep-alive for this request + mg.request_info -- a table with the following request information + .remote_addr -- IP address of the client as string + .remote_port -- remote port number + .server_port -- server port number + .request_method -- HTTP method (e.g.: GET, POST) + .http_version -- HTTP protocol version (e.g.: 1.1) + .uri -- resource name + .query_string -- query string if present, nil otherwise + .script_name -- name of the Lua script + .https -- true if accessed by https://, false otherwise + .remote_user -- user name if authenticated, nil otherwise + +connect (function): + + -- Connect to the remote TCP server. This function is an implementation + -- of simple socket interface. It returns a socket object with three + -- methods: send, recv, close, which are synchronous (blocking). + -- connect() throws an exception on connection error. + connect(host, port, use_ssl) + + -- Example of using connect() interface: + local host = 'code.google.com' -- IP address or domain name + local ok, sock = pcall(connect, host, 80, 1) + if ok then + sock:send('GET /p/civetweb/ HTTP/1.0\r\n' .. + 'Host: ' .. host .. '\r\n\r\n') + local reply = sock:recv() + sock:close() + -- reply now contains the web page https://code.google.com/p/civetweb + end + + +All filename arguments are either absolute or relative to the civetweb working +directory (not the document root or the Lua script/page file). + +**IMPORTANT: Civetweb does not send HTTP headers for Lua pages. Therefore, +every Lua Page must begin with a HTTP reply line and headers**, like this: + + <? mg.write('HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n') ?> + <html><body> + ... the rest of the web page ... + +To serve a Lua Page, civetweb creates a Lua context. That context is used for +all Lua blocks within the page. That means, all Lua blocks on the same page +share the same context. If one block defines a variable, for example, that +variable is visible in all block that follow. + +## Websockets for Lua +Civetweb offers support for websockets in Lua as well. In contrast to plain +Lua scripts and Lua server pages, Lua websocket scripts are shared by all clients. + +Lua websocket scripts must define a few functions: + open(arg) -- callback to accept or reject a connection + ready(arg) -- called after a connection has been established + data(arg) -- called when the server receives data from the client + close(arg) -- called when a websocket connection is closed +All function are called with one argument of type table with at least one field +"client" to identify the client. When "open" is called, the argument table additionally +contains the "request_info" table as defined above. For the "data" handler, an +additional field "data" is available. The functions "open", "ready" and "data" +must return true in order to keep the connetion open. + +Lua websocket pages do support single shot (timeout) and interval timers. + +An example is shown in +[websocket.lua](https://github.com/civetweb/civetweb/blob/master/test/websocket.lua). + + +# Common Problems +- PHP doesn't work - getting empty page, or 'File not found' error. The + reason for that is wrong paths to the interpreter. Remember that with PHP, + the correct interpreter is `php-cgi.exe` (`php-cgi` on UNIX). + Solution: specify the full path to the PHP interpreter, e.g.: + `civetweb -cgi_interpreter /full/path/to/php-cgi` + +- `php-cgi` is unavailable, for example on Mac OS X. As long as the `php` binary is installed, you can run CGI programs in command line mode (see the example below). Note that in this mode, `$_GET` and friends will be unavailable, and you'll have to parse the query string manually using [parse_str](http://php.net/manual/en/function.parse-str.php) and the `QUERY_STRING` environmental variable. + + #!/usr/bin/php + <?php + echo "Content-Type: text/html\r\n\r\n"; + echo "Hello World!\n"; + ?> + +- Civetweb fails to start. If Civetweb exits immediately when started, this + usually indicates a syntax error in the configuration file + (named `civetweb.conf` by default) or the command-line arguments. + Syntax checking is omitted from Civetweb to keep its size low. However, + the Manual should be of help. Note: the syntax changes from time to time, + so updating the config file might be necessary after executable update. + +- Embedding with OpenSSL on Windows might fail because of calling convention. + To force Civetweb to use `__stdcall` convention, add `/Gz` compilation + flag in Visual Studio compiler. + |