Update to 7.40.1

[platform/upstream/curl.git] / docs / FAQ

diff --git a/docs/FAQ b/docs/FAQ
index 0850bd4..043b7bb 100644 (file)
--- a/docs/FAQ
+++ b/docs/FAQ
@@ -80,6 +80,7 @@ FAQ
   4.17 Non-functional connect timeouts on Windows
   4.18 file:// URLs containing drive letters (Windows, NetWare)
   4.19 Why doesn't cURL return an error when the network cable is unplugged?
   4.17 Non-functional connect timeouts on Windows
   4.18 file:// URLs containing drive letters (Windows, NetWare)
   4.19 Why doesn't cURL return an error when the network cable is unplugged?

+  4.20 curl doesn't return error for HTTP non-200 responses!

 
  5. libcurl Issues
   5.1 Is libcurl thread-safe?
 
  5. libcurl Issues
   5.1 Is libcurl thread-safe?


@@ -133,14 +134,14 @@ FAQ
 
     A free and easy-to-use client-side URL transfer library, supporting DICT,
     FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3,
 
     A free and easy-to-use client-side URL transfer library, supporting DICT,
     FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3,

-    POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, TELNET and TFTP.
+    POP3S, RTMP, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP.

 
     libcurl supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading,
 
     libcurl supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading,

-    kerberos, HTTP form based upload, proxies, cookies, user+password
+    Kerberos, SPNEGO, HTTP form based upload, proxies, cookies, user+password

     authentication, file transfer resume, http proxy tunneling and more!
 
     libcurl is highly portable, it builds and works identically on numerous
     authentication, file transfer resume, http proxy tunneling and more!
 
     libcurl is highly portable, it builds and works identically on numerous

-    platforms, including Solaris, NetBSD, FreeBSD, OpenBSD, Darwin, HPUX,
+    platforms, including Solaris, NetBSD, FreeBSD, OpenBSD, Darwin, HP-UX,

     IRIX, AIX, Tru64, Linux, UnixWare, HURD, Windows, Amiga, OS/2, BeOS, Mac
     OS X, Ultrix, QNX, OpenVMS, RISC OS, Novell NetWare, DOS, Symbian, OSF,
     Android, Minix, IBM TPF and more...
     IRIX, AIX, Tru64, Linux, UnixWare, HURD, Windows, Amiga, OS/2, BeOS, Mac
     OS X, Ultrix, QNX, OpenVMS, RISC OS, Novell NetWare, DOS, Symbian, OSF,
     Android, Minix, IBM TPF and more...


@@ -155,7 +156,10 @@ FAQ
     Since curl uses libcurl, curl supports the same wide range of common
     Internet protocols that libcurl does.
 
     Since curl uses libcurl, curl supports the same wide range of common
     Internet protocols that libcurl does.
 

-  We pronounce curl and cURL with an initial k sound: [kurl].
+  We pronounce curl with an initial k sound. It rhymes with words like girl
+  and earl. This is a short WAV file to help you:
+
+     http://media.merriam-webster.com/soundc11/c/curl0001.wav

 
   There are numerous sub-projects and related projects that also use the word
   curl in the project names in various combinations, but you should take
 
   There are numerous sub-projects and related projects that also use the word
   curl in the project names in various combinations, but you should take


@@ -238,10 +242,10 @@ FAQ
   1.6 What do you get for making curl?
 
   Project cURL is entirely free and open. No person gets paid for developing
   1.6 What do you get for making curl?
 
   Project cURL is entirely free and open. No person gets paid for developing

-  (lib)curl on full or even part time. We do this voluntarily on our spare
-  time. Occasionally companies pay individual developers to work on curl, but
-  that's up to each company and developer. It is not controlled by nor
-  supervised in any way by the project.
+  curl on full time. We do this voluntarily, mostly on spare time.
+  Occasionally companies pay individual developers to work on curl, but that's
+  up to each company and developer. It is not controlled by nor supervised in
+  any way by the project.

 
   We still get help from companies. Haxx provides web site, bandwidth, mailing
   lists etc, sourceforge.net hosts project services we take advantage from,
 
   We still get help from companies. Haxx provides web site, bandwidth, mailing
   lists etc, sourceforge.net hosts project services we take advantage from,


@@ -423,7 +427,7 @@ FAQ
 
   curl can be built to use one of the following SSL alternatives: OpenSSL,
   GnuTLS, yassl, NSS, PolarSSL, axTLS, Secure Transport (native iOS/OS X),
 
   curl can be built to use one of the following SSL alternatives: OpenSSL,
   GnuTLS, yassl, NSS, PolarSSL, axTLS, Secure Transport (native iOS/OS X),

-  WinSSL (native Windows) or qssl (native IBM i). They all have their pros
+  WinSSL (native Windows) or GSKit (native IBM i). They all have their pros

   and cons, and we try to maintain a comparison of them here:
   http://curl.haxx.se/docs/ssl-compared.html
 
   and cons, and we try to maintain a comparison of them here:
   http://curl.haxx.se/docs/ssl-compared.html
 


@@ -1086,7 +1090,31 @@ FAQ
   immediately if its lone network connection goes down.  That can be achieved
   by having the application monitor the network connection on its own using an
   OS-specific mechanism, then signalling libcurl to abort (see also item 5.13).
   immediately if its lone network connection goes down.  That can be achieved
   by having the application monitor the network connection on its own using an
   OS-specific mechanism, then signalling libcurl to abort (see also item 5.13).

-  
+
+  4.20 curl doesn't return error for HTTP non-200 responses!
+
+  Correct. Unless you use -f (--fail).
+
+  When doing HTTP transfers, curl will perform exactly what you're asking it
+  to do and if successful it will not return an error. You can use curl to
+  test your web server's "file not found" page (that gets 404 back), you can
+  use it to check your authentication protected web pages (that get a 401
+  back) and so on.
+
+  The specific HTTP response code does not constitute a problem or error for
+  curl. It simply sends and delivers HTTP as you asked and if that worked,
+  everything is fine and dandy. The response code is generally providing more
+  higher level error information that curl doesn't care about. The error was
+  not in the HTTP transfer.
+
+  If you want your command line to treat error codes in the 400 and up range
+  as errors and thus return a non-zero value and possibly show an error
+  message, curl has a dedicated option for that: -f (CURLOPT_FAILONERROR in
+  libcurl speak).
+
+  You can also use the -w option and the variable %{response_code} to extract
+  the exact response code that was return in the response.
+

 
 5. libcurl Issues
 
 
 5. libcurl Issues
 


@@ -1246,7 +1274,7 @@ FAQ
   you want to change name resolver function you must rebuild libcurl and tell
   it to use a different function.
 
   you want to change name resolver function you must rebuild libcurl and tell
   it to use a different function.
 

-  - The non-ipv6 resolver that can use one out of four host name resolve calls
+  - The non-IPv6 resolver that can use one out of four host name resolve calls

     (depending on what your system supports):
 
       A - gethostbyname()
     (depending on what your system supports):
 
       A - gethostbyname()


@@ -1254,15 +1282,15 @@ FAQ
       C - gethostbyname_r() with 5 arguments
       D - gethostbyname_r() with 6 arguments
 
       C - gethostbyname_r() with 5 arguments
       D - gethostbyname_r() with 6 arguments
 

-  - The ipv6-resolver that uses getaddrinfo()
+  - The IPv6-resolver that uses getaddrinfo()

 
   - The c-ares based name resolver that uses the c-ares library for resolves.
     Using this offers asynchronous name resolves.
 
   - The threaded resolver (default option on Windows). It uses:
 
 
   - The c-ares based name resolver that uses the c-ares library for resolves.
     Using this offers asynchronous name resolves.
 
   - The threaded resolver (default option on Windows). It uses:
 

-      A - gethostbyname() on plain ipv4 hosts
-      B - getaddrinfo() on ipv6-enabled hosts
+      A - gethostbyname() on plain IPv4 hosts
+      B - getaddrinfo() on IPv6 enabled hosts

 
   Also note that libcurl never resolves or reverse-lookups addresses given as
   pure numbers, such as 127.0.0.1 or ::1.
 
   Also note that libcurl never resolves or reverse-lookups addresses given as
   pure numbers, such as 127.0.0.1 or ::1.