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@@ -121,106 +121,139 @@ FAQ 9. Why do I get problems when I use & in the URL? - In general unix shells, the & letter is treated special and when used it - runs the specified command in the background. To safely send the & as a - part of a URL, you should qoute the entire URL by using single (') or - double (") quotes around it. + In general unix shells, the & letter is treated special and when used it + runs the specified command in the background. To safely send the & as a part + of a URL, you should qoute the entire URL by using single (') or double (") + quotes around it. - An example that would invoke a remote CGI that uses &-letters could be: + An example that would invoke a remote CGI that uses &-letters could be: curl 'http://www.altavista.com/cgi-bin/query?text=yes&q=curl' 10. How can I use {, }, [ or ] to specify multiple URLs? - Because those letters have a special meaning to the shell, and to be used - in a URL specified to curl you must quote them. + Because those letters have a special meaning to the shell, and to be used in + a URL specified to curl you must quote them. - An example that downloads two URLs (sequentially) would do: + An example that downloads two URLs (sequentially) would do: curl '{curl,www}.haxx.se' 11. Where can I find a copy of LIBEAY32.DLL? - That is an OpenSSL binary built for Windows. + That is an OpenSSL binary built for Windows. - Curl uses OpenSSL to do the SSL stuff. The LIBEAY32.DLL is what curl needs - on a windows machine to do https://. Check out the curl web page to find - accurate and up-to-date pointers to recent OpenSSL DDLs and other binary - packages. + Curl uses OpenSSL to do the SSL stuff. The LIBEAY32.DLL is what curl needs + on a windows machine to do https://. Check out the curl web page to find + accurate and up-to-date pointers to recent OpenSSL DDLs and other binary + packages. 12. Why do I get downloaded data even though the web page doesn't exist? - Curl asks remote servers for the page you specify. If the page doesn't - exist at the server, the HTTP protocol defines how the server should - respond and that means that headers and a "page" will be returned. That's - simply how HTTP works. + Curl asks remote servers for the page you specify. If the page doesn't exist + at the server, the HTTP protocol defines how the server should respond and + that means that headers and a "page" will be returned. That's simply how + HTTP works. - By using the --fail option you can tell curl explicitly to not get any data - if the HTTP return code doesn't say success. + By using the --fail option you can tell curl explicitly to not get any data + if the HTTP return code doesn't say success. 13. Why do I get "HTTP/1.1 403 Forbidden" from a http server? - RFC2616 clearly explains this return code: + RFC2616 clearly explains this return code: - 10.4.4 403 Forbidden + 10.4.4 403 Forbidden - The server understood the request, but is refusing to fulfill it. - Authorization will not help and the request SHOULD NOT be repeated. - If the request method was not HEAD and the server wishes to make - public why the request has not been fulfilled, it SHOULD describe the - reason for the refusal in the entity. If the server does not wish to - make this information available to the client, the status code 404 - (Not Found) can be used instead. + The server understood the request, but is refusing to fulfill it. + Authorization will not help and the request SHOULD NOT be repeated. If the + request method was not HEAD and the server wishes to make public why the + request has not been fulfilled, it SHOULD describe the reason for the + refusal in the entity. If the server does not wish to make this information + available to the client, the status code 404 (Not Found) can be used + instead. 14. How can I disable the Pragma: nocache header? - You can change all internally generated headers by adding a replacement - with the -H/--header option. By adding a header with empty contents you - safelt disables the headers. Use -H "Pragma:" to disable that specific - header. + You can change all internally generated headers by adding a replacement with + the -H/--header option. By adding a header with empty contents you safelt + disables the headers. Use -H "Pragma:" to disable that specific header. 15. Can you tell me what error code 142 means? - All error codes that are larger than the highest documented error code - means that curl has existed due to a timeout. There is currentl no nice way - for curl to abort from such a condition and that's why it gets this - undocumented error. This is planned to change in a future release. + All error codes that are larger than the highest documented error code means + that curl has existed due to a timeout. There is currentl no nice way for + curl to abort from such a condition and that's why it gets this undocumented + error. This is planned to change in a future release. 16. How do I keep usernames and passwords secret in Curl command lines? - I see this problem as two parts: + I see this problem as two parts: - The first part is to avoid having clear-text passwords in the command line - so that they don't appear in 'ps' outputs and similar. That is easily - avoided by using the "-K" option that tells curl to read parameters from a - file or stdin to which you can pass the secret info. + The first part is to avoid having clear-text passwords in the command line + so that they don't appear in 'ps' outputs and similar. That is easily + avoided by using the "-K" option tho tell curl to read parameters from a + file or stdin to which you can pass the secret info. - To keep the passwords in your account secret from the rest of the world is - not a task that curl addresses. You could of course encrypt them somehow to - at least hide them from being read by human eyes, but that is not what - anyone would call security. + To keep the passwords in your account secret from the rest of the world is + not a task that curl addresses. You could of course encrypt them somehow to + at least hide them from being read by human eyes, but that is not what + anyone would call security. 17. Does curl support javascript, ASP, XML, XHTML or HTML version Y? - To curl, all contents are alike. It doesn't matter how the page was - generated. It may be ASP, PHP, perl, shell-script, SSI or plain - HTML-files. There's no difference to curl and it doesn't even know what - kind of language that generated the page. + To curl, all contents are alike. It doesn't matter how the page was + generated. It may be ASP, PHP, perl, shell-script, SSI or plain + HTML-files. There's no difference to curl and it doesn't even know what kind + of language that generated the page. - Javascript is slightly different since that is code embedded in the HTML - that is sent for the client to interpret and curl has no javascript - interpreter. + Javascript is slightly different since that is code embedded in the HTML + that is sent for the client to interpret and curl has no javascript + interpreter. 18. Does cURL support Socks (RFC 1928) ? - No. Nobody has wanted it that badly yet. I would appriciate patches that - brings this functionality. + No. Nobody has wanted it that badly yet. I would appriciate patches that + brings this functionality. 19. Can I use curl to delete/rename a file through FTP? - Yes. You specify custom ftp commands with -Q/--quote. + Yes. You specify custom ftp commands with -Q/--quote. - One example would be to delete a file after you have downloaded it: + One example would be to delete a file after you have downloaded it: curl -O ftp://download.com/coolfile -Q '-DELE coolfile' +20. Can I use curl/libcurl in my program licensed under XXX? + + Curl and libcurl are released under the MPL, the Mozilla Public License. To + get a really good answer to this or other licensing questions, you should + study the MPL license and the license you are about to use and check for + clashes yourself. This is a brief summary for a few cases for which we get + questions: + + I have a GPL program, can I use the libcurl library? + + No. GPL'd software requires all parts of the final executable to be + licensed under GPL. + + I have a closed-source program, can I use the libcurl library? + + Yes, libcurl does not put any restrictions on the program that uses the + library. If you end up doing changes to the library, only those changes + must be made available, not the ones to your program. + + I have a program that uses LGPL libraries, can I use libcurl? + + Yes you can. LGPL libraries don't spread to other libraries the same way + GPL ones do. + + Can I modify curl/libcurl for my own program and keep the changes secret? + + No, you're not allowed to do that. + + Can you please change the curl/libcurl license to XXXX? + + No. We carefully picked this license years ago and a large amount of + people have contributed with source code knowing that this is the license + we use. This license puts the restrictions we want on curl/libcurl and it + does not spread to other programs or libraries. |