updated
This commit is contained in:
Daniel Stenberg
Родитель
fe4580eee1
Коммит
e9640b6831
293
docs/FAQ
293
docs/FAQ
|
|
@ -6,89 +6,50 @@
|
|||
|
||||
FAQ
|
||||
|
||||
1. Problems connecting to SSL servers.
|
||||
1. Install Related Problems
|
||||
1.1 configure doesn't find OpenSSL even when it is installed
|
||||
1.1.1. native linker doesn't find openssl
|
||||
1.1.2. only the libssl lib is missing
|
||||
1.2 Does curl work/build with other SSL libraries?
|
||||
1.3 Where can I find a copy of LIBEAY32.DLL?
|
||||
1.4 Does cURL support Socks (RFC 1928) ?
|
||||
|
||||
It took a very long time before I could sort out why curl had problems
|
||||
to connect to certain SSL servers when using SSLeay or OpenSSL v0.9+.
|
||||
The error sometimes showed up similar to:
|
||||
2. Usage problems
|
||||
2.1 curl: (1) SSL is disabled, https: not supported
|
||||
2.2 How do I tell curl to resume a transfer?
|
||||
2.3 Why doesn't my posting using -F work?
|
||||
2.4 How do I tell curl to run custom FTP commands?
|
||||
2.5 How can I disable the Pragma: nocache header?
|
||||
2.6 Does curl support javascript, ASP, XML, XHTML or HTML version Y?
|
||||
2.7 Can I use curl to delete/rename a file through FTP?
|
||||
|
||||
16570:error:1407D071:SSL routines:SSL2_READ:bad mac decode:s2_pkt.c:233:
|
||||
3. Running Problems
|
||||
3.1 Problems connecting to SSL servers.
|
||||
3.2 Why do I get problems when I use & in the URL?
|
||||
3.3 How can I use {, }, [ or ] to specify multiple URLs?
|
||||
3.4 Why do I get downloaded data even though the web page doesn't exist?
|
||||
3.5 Why do I get "HTTP/1.1 403 Forbidden" from a http server?
|
||||
3.6 Can you tell me what error code 142 means?
|
||||
|
||||
It turned out to be because many older SSL servers don't deal with SSLv3
|
||||
requests properly. To correct this problem, tell curl to select SSLv2 from
|
||||
the command line (-2/--sslv2).
|
||||
4. libcurl issues
|
||||
4.1 Is libcurl thread safe?
|
||||
|
||||
I have also seen examples where the remote server didn't like the SSLv2
|
||||
request and instead you had to force curl to use SSLv3 with -3/--sslv3.
|
||||
5. license issues
|
||||
5.1 I have a GPL program, can I use the libcurl library?
|
||||
5.2 I have a closed-source program, can I use the libcurl library?
|
||||
5.3 I have a program that uses LGPL libraries, can I use libcurl?
|
||||
5.4 Can I modify curl/libcurl for my program and keep the changes secret?
|
||||
5.5 Can you please change the curl/libcurl license to XXXX?
|
||||
|
||||
2. curl: (1) SSL is disabled, https: not supported
|
||||
|
||||
|
||||
If you get this output when trying to get anything from a https:// server,
|
||||
it means that the configure script couldn't find all libs and include files
|
||||
it requires for SSL to work. If the configure script fails to find them,
|
||||
curl is simply built without SSL support.
|
||||
1. Install Related Problems
|
||||
|
||||
To get the https:// support into a curl that was previously built but that
|
||||
reports that https:// is not supported, you should dig through the document
|
||||
and logs and check out why the configure script doesn't find the SSL libs
|
||||
and/or include files.
|
||||
|
||||
Also, check out the other paragraph in this FAQ labeled "configure doesn't
|
||||
find OpenSSL even when it is installed".
|
||||
|
||||
3. Does curl support resume?
|
||||
|
||||
Yes. Both ways on FTP, download ways on HTTP.
|
||||
|
||||
Try the -c and -C options.
|
||||
|
||||
4. Is libcurl thread safe?
|
||||
|
||||
As version seven is slowly marching in as the libcurl version to use, we
|
||||
have made a serious attempt to address all places in the code where we could
|
||||
forsee problems for multi-threaded programs. If your system has them, curl
|
||||
will attempt to use threadsafe functions instead of non-safe ones.
|
||||
|
||||
I am very interested in once and for all getting some kind of report or
|
||||
README file from those who have used libcurl in a threaded environment,
|
||||
since I haven't and I get this question more and more frequently!
|
||||
|
||||
5. Why doesn't my posting using -F work?
|
||||
|
||||
You can't simply use -F or -d at your choice. The web server that will
|
||||
receive your post assumes one of the formats. If the form you're trying to
|
||||
"fake" sets the type to 'multipart/form-data', than and only then you must
|
||||
use the -F type. In all the most common cases, you should use -d which then
|
||||
causes a posting with the type 'application/x-www-form-urlencoded'.
|
||||
|
||||
I have described this in some detail in the README.curl file, and if you
|
||||
don't understand it the first time, read it again before you post questions
|
||||
about this to the mailing list. I would also suggest that you read through
|
||||
the mailing list archives for old postings and questions regarding this.
|
||||
|
||||
6. Does curl support custom FTP commands?
|
||||
|
||||
Yes it does, you can tell curl to perform optional commands both before
|
||||
and/or after a file transfer. Study the -Q/--quote option.
|
||||
|
||||
Since curl is used for file transfers, you don't use curl to just perform
|
||||
ftp commands without transfering anything. Therefore you must always specify
|
||||
a URL to transfer to/from even when doing custom FTP commands.
|
||||
|
||||
7. Does curl work with other SSL libraries?
|
||||
|
||||
Curl has been written to use OpenSSL, although I doubt there would be much
|
||||
problems using a different library. I just don't know any other free one and
|
||||
that has limited my possibilities to develop against anything else.
|
||||
|
||||
If anyone does "port" curl to use a commercial SSL library, I am of course
|
||||
very interested in getting the patch!
|
||||
|
||||
8. configure doesn't find OpenSSL even when it is installed
|
||||
1.1. configure doesn't find OpenSSL even when it is installed
|
||||
|
||||
This may be because of several reasons.
|
||||
|
||||
8.1. native linker doesn't find openssl
|
||||
1.1.1. native linker doesn't find openssl
|
||||
|
||||
Platforms: Solaris (native cc compiler) and HPUX (native cc compiler)
|
||||
|
||||
|
|
@ -106,7 +67,7 @@ FAQ
|
|||
|
||||
Submitted by: Bob Allison <allisonb@users.sourceforge.net>
|
||||
|
||||
8.2. only the libssl lib is missing
|
||||
1.1.2. only the libssl lib is missing
|
||||
|
||||
If all include files and the libcrypto lib is present, with only the
|
||||
libssl being missing according to configure, this is mostly likely because
|
||||
|
|
@ -119,7 +80,120 @@ FAQ
|
|||
configure. Make sure that you remove the config.cache file before you
|
||||
rerun configure with the new flags.
|
||||
|
||||
9. Why do I get problems when I use & in the URL?
|
||||
1.2. Does curl work/build with other SSL libraries?
|
||||
|
||||
Curl has been written to use OpenSSL, although I doubt there would be much
|
||||
problems using a different library. I just don't know any other free one and
|
||||
that has limited my possibilities to develop against anything else.
|
||||
|
||||
If anyone does "port" curl to use a commercial SSL library, I am of course
|
||||
very interested in getting the patch!
|
||||
|
||||
1.3. Where can I find a copy of LIBEAY32.DLL?
|
||||
|
||||
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.
|
||||
|
||||
1.4. Does cURL support Socks (RFC 1928) ?
|
||||
|
||||
No. Nobody has wanted it that badly yet. I would appriciate patches that
|
||||
brings this functionality.
|
||||
|
||||
|
||||
|
||||
2. Usage problems
|
||||
|
||||
2.1. curl: (1) SSL is disabled, https: not supported
|
||||
|
||||
If you get this output when trying to get anything from a https:// server,
|
||||
it means that the configure script couldn't find all libs and include files
|
||||
it requires for SSL to work. If the configure script fails to find them,
|
||||
curl is simply built without SSL support.
|
||||
|
||||
To get the https:// support into a curl that was previously built but that
|
||||
reports that https:// is not supported, you should dig through the document
|
||||
and logs and check out why the configure script doesn't find the SSL libs
|
||||
and/or include files.
|
||||
|
||||
Also, check out the other paragraph in this FAQ labeled "configure doesn't
|
||||
find OpenSSL even when it is installed".
|
||||
|
||||
2.2. How do I tell curl to resume a transfer?
|
||||
|
||||
Curl supports resume both ways on FTP, download ways on HTTP.
|
||||
|
||||
Try the -c and -C options.
|
||||
|
||||
2.3. Why doesn't my posting using -F work?
|
||||
|
||||
You can't simply use -F or -d at your choice. The web server that will
|
||||
receive your post assumes one of the formats. If the form you're trying to
|
||||
"fake" sets the type to 'multipart/form-data', than and only then you must
|
||||
use the -F type. In all the most common cases, you should use -d which then
|
||||
causes a posting with the type 'application/x-www-form-urlencoded'.
|
||||
|
||||
I have described this in some detail in the README.curl file, and if you
|
||||
don't understand it the first time, read it again before you post questions
|
||||
about this to the mailing list. I would also suggest that you read through
|
||||
the mailing list archives for old postings and questions regarding this.
|
||||
|
||||
2.4. How do I tell curl to run custom FTP commands?
|
||||
|
||||
You can tell curl to perform optional commands both before and/or after a
|
||||
file transfer. Study the -Q/--quote option.
|
||||
|
||||
Since curl is used for file transfers, you don't use curl to just perform
|
||||
ftp commands without transfering anything. Therefore you must always specify
|
||||
a URL to transfer to/from even when doing custom FTP commands.
|
||||
|
||||
2.5. 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 safely
|
||||
disable that one. Use -H "Pragma:" to disable that specific header.
|
||||
|
||||
2.6. 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.
|
||||
|
||||
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.
|
||||
|
||||
2.7. Can I use curl to delete/rename a file through FTP?
|
||||
|
||||
Yes. You specify custom ftp commands with -Q/--quote.
|
||||
|
||||
One example would be to delete a file after you have downloaded it:
|
||||
|
||||
curl -O ftp://download.com/coolfile -Q '-DELE coolfile'
|
||||
|
||||
|
||||
3. Running Problems
|
||||
|
||||
3.1. Problems connecting to SSL servers.
|
||||
|
||||
It took a very long time before I could sort out why curl had problems
|
||||
to connect to certain SSL servers when using SSLeay or OpenSSL v0.9+.
|
||||
The error sometimes showed up similar to:
|
||||
|
||||
16570:error:1407D071:SSL routines:SSL2_READ:bad mac decode:s2_pkt.c:233:
|
||||
|
||||
It turned out to be because many older SSL servers don't deal with SSLv3
|
||||
requests properly. To correct this problem, tell curl to select SSLv2 from
|
||||
the command line (-2/--sslv2).
|
||||
|
||||
I have also seen examples where the remote server didn't like the SSLv2
|
||||
request and instead you had to force curl to use SSLv3 with -3/--sslv3.
|
||||
|
||||
3.2. 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
|
||||
|
|
@ -130,7 +204,7 @@ FAQ
|
|||
|
||||
curl 'http://www.altavista.com/cgi-bin/query?text=yes&q=curl'
|
||||
|
||||
10. How can I use {, }, [ or ] to specify multiple URLs?
|
||||
3.3. 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.
|
||||
|
|
@ -139,16 +213,7 @@ FAQ
|
|||
|
||||
curl '{curl,www}.haxx.se'
|
||||
|
||||
11. Where can I find a copy of LIBEAY32.DLL?
|
||||
|
||||
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.
|
||||
|
||||
12. Why do I get downloaded data even though the web page doesn't exist?
|
||||
3.4. 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
|
||||
|
|
@ -158,11 +223,11 @@ FAQ
|
|||
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?
|
||||
3.5. Why do I get "HTTP/1.1 403 Forbidden" from a http server?
|
||||
|
||||
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
|
||||
|
|
@ -171,21 +236,15 @@ FAQ
|
|||
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.
|
||||
|
||||
15. Can you tell me what error code 142 means?
|
||||
|
||||
3.6. 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.
|
||||
|
||||
16. How do I keep usernames and passwords secret in Curl command lines?
|
||||
3.7. How do I keep usernames and passwords secret in Curl command lines?
|
||||
|
||||
I see this problem as two parts:
|
||||
|
||||
|
|
@ -199,31 +258,21 @@ FAQ
|
|||
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.
|
||||
4. libcurl issues
|
||||
|
||||
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.
|
||||
4.1. Is libcurl thread safe?
|
||||
|
||||
18. Does cURL support Socks (RFC 1928) ?
|
||||
As version seven is slowly marching in as the libcurl version to use, we
|
||||
have made a serious attempt to address all places in the code where we could
|
||||
forsee problems for multi-threaded programs. If your system has them, curl
|
||||
will attempt to use threadsafe functions instead of non-safe ones.
|
||||
|
||||
No. Nobody has wanted it that badly yet. I would appriciate patches that
|
||||
brings this functionality.
|
||||
I am very interested in once and for all getting some kind of report or
|
||||
README file from those who have used libcurl in a threaded environment,
|
||||
since I haven't and I get this question more and more frequently!
|
||||
|
||||
19. Can I use curl to delete/rename a file through FTP?
|
||||
|
||||
Yes. You specify custom ftp commands with -Q/--quote.
|
||||
|
||||
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?
|
||||
5. license issues
|
||||
|
||||
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
|
||||
|
|
@ -231,27 +280,27 @@ FAQ
|
|||
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?
|
||||
5.1. 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?
|
||||
5.2. 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?
|
||||
5.3. 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?
|
||||
5.4. Can I modify curl/libcurl for my program and keep the changes secret?
|
||||
|
||||
No, you're not allowed to do that.
|
||||
|
||||
Can you please change the curl/libcurl license to XXXX?
|
||||
5.5. 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
|
||||
|
|
|
|||
37
docs/curl.1
37
docs/curl.1
|
|
@ -2,7 +2,7 @@
|
|||
.\" nroff -man curl.1
|
||||
.\" Written by Daniel Stenberg
|
||||
.\"
|
||||
.TH curl 1 "26 July 2000" "Curl 7.0" "Curl Manual"
|
||||
.TH curl 1 "1 August 2000" "Curl 7.0" "Curl Manual"
|
||||
.SH NAME
|
||||
curl \- get a URL with FTP, TELNET, LDAP, GOPHER, DICT, FILE, HTTP or
|
||||
HTTPS syntax.
|
||||
|
|
@ -150,13 +150,14 @@ name should've been. This goes for both @ and < constructs.
|
|||
.IP "-h/--help"
|
||||
Usage help.
|
||||
.IP "-H/--header <header>"
|
||||
(HTTP)
|
||||
Extra header to use when getting a web page. You may specify any number of
|
||||
extra headers. Note that if you should add a custom header that has the same
|
||||
name as one of the internal ones curl would use, your externally set header
|
||||
will be used instead of the internal one. This allows you to make even
|
||||
(HTTP) Extra header to use when getting a web page. You may specify any number
|
||||
of extra headers. Note that if you should add a custom header that has the
|
||||
same name as one of the internal ones curl would use, your externally set
|
||||
header will be used instead of the internal one. This allows you to make even
|
||||
trickier stuff than curl would normally do. You should not replace internally
|
||||
set headers without knowing perfectly well what you're doing.
|
||||
set headers without knowing perfectly well what you're doing. Replacing an
|
||||
internal header with one without content on the right side of the colon will
|
||||
prevent that header from appearing.
|
||||
.IP "-i/--include"
|
||||
(HTTP)
|
||||
Include the HTTP-header in the output. The HTTP-header includes things
|
||||
|
|
@ -181,16 +182,16 @@ Especially useful if you want to machine-parse the contents of an FTP
|
|||
directory since the normal directory view doesn't use a standard look
|
||||
or format.
|
||||
.IP "-L/--location"
|
||||
(HTTP/HTTPS)
|
||||
If the server reports that the requested page has a different location
|
||||
(indicated with the header line Location:) this flag will let curl
|
||||
attempt to reattempt the get on the new place. If used together with
|
||||
-i or -I, headers from all requested pages will be shown.
|
||||
(HTTP/HTTPS) If the server reports that the requested page has a different
|
||||
location (indicated with the header line Location:) this flag will let curl
|
||||
attempt to reattempt the get on the new place. If used together with -i or -I,
|
||||
headers from all requested pages will be shown. If this flag is used when
|
||||
making a HTTP POST, curl will automatically switch to GET after the initial
|
||||
POST has been done.
|
||||
.IP "-m/--max-time <seconds>"
|
||||
Maximum time in seconds that you allow the whole operation to take.
|
||||
This is useful for preventing your batch jobs from hanging for hours
|
||||
due to slow networks or links going down.
|
||||
This doesn't work properly in win32 systems.
|
||||
Maximum time in seconds that you allow the whole operation to take. This is
|
||||
useful for preventing your batch jobs from hanging for hours due to slow
|
||||
networks or links going down. This doesn't work fully in win32 systems.
|
||||
.IP "-M/--manual"
|
||||
Manual. Display the huge help text.
|
||||
.IP "-n/--netrc"
|
||||
|
|
@ -415,7 +416,9 @@ date, or one that has been modified before that time. The date expression can
|
|||
be all sorts of date strings or if it doesn't match any internal ones, it
|
||||
tries to get the time from a given file name instead! See the
|
||||
.BR "GNU date(1)"
|
||||
man page for date expression details.
|
||||
or
|
||||
.BR "curl_getdate(3)"
|
||||
man pages for date expression details.
|
||||
|
||||
Start the date expression with a dash (-) to make it request for a document
|
||||
that is older than the given date/time, default is a document that is newer
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче