Implementation notes: This is a true OS/400 ILE implementation, not a PASE implementation (for PASE, use AIX implementation). The biggest problem with OS/400 is EBCDIC. Libcurl implements an internal conversion mechanism, but it has been designed for computers that have a single native character set. OS/400 default native character set varies depending on the country for which it has been localized. And more, a job may dynamically alter its "native" character set. Several characters that do not have fixed code in EBCDIC variants are used in libcurl strings. As a consequence, using the existing conversion mechanism would have lead in a localized binary library - not portable across countries. For this reason, and because libcurl was originally designed for ASCII based operating systems, the current OS/400 implementation uses ASCII as internal character set. This has been accomplished using the QADRT library and include files, a C and system procedures ASCII wrapper library. See IBM QADRT description for more information. This then results in libcurl being an ASCII library: any function string argument is taken/returned in ASCII and a C/C++ calling program built around QADRT may use libcurl functions as on any other platform. QADRT does not define ASCII wrappers for all C/system procedures: the OS/400 configuration header file and an additional module (os400sys.c) define some more of them, that are used by libcurl and that QADRT left out. To support all the different variants of EBCDIC, non-standard wrapper procedures have been added to libcurl on OS/400: they provide an additional CCSID (numeric Coded Character Set ID specific to OS/400) parameter for each string argument. Callback procedures arguments giving access to strings are NOT converted, so text gathered this way is (probably !) ASCII. Another OS/400 problem comes from the fact that the last fixed argument of a vararg procedure may not be of type char, unsigned char, short or unsigned short. Enums that are internally implemented by the C compiler as one of these types are also forbidden. Libcurl uses enums as vararg procedure tagfields... Happily, there is a pragma forcing enums to type "int". The original libcurl header files are thus altered during build process to use this pragma, in order to force libcurl enums of being type int (the pragma disposition in use before inclusion is restored before resuming the including unit compilation). Non-standard EBCDIC wrapper prototypes are defined in an additional header file: ccsidcurl.h. These should be self-explanatory to an OS/400-aware designer. CCSID 0 can be used to select the current job's CCSID. Wrapper procedures with variable arguments are described below: _ curl_easy_setopt_ccsid() Variable arguments are a string pointer and a CCSID (unsigned int) for options: CURLOPT_ABSTRACT_UNIX_SOCKET CURLOPT_ACCEPT_ENCODING CURLOPT_ALTSVC CURLOPT_AWS_SIGV4 CURLOPT_CAINFO CURLOPT_CAPATH CURLOPT_COOKIE CURLOPT_COOKIEFILE CURLOPT_COOKIEJAR CURLOPT_COOKIELIST CURLOPT_CRLFILE CURLOPT_CUSTOMREQUEST CURLOPT_DEFAULT_PROTOCOL CURLOPT_DNS_INTERFACE CURLOPT_DNS_LOCAL_IP4 CURLOPT_DNS_LOCAL_IP6 CURLOPT_DNS_SERVERS CURLOPT_DOH_URL CURLOPT_EGDSOCKET CURLOPT_FTPPORT CURLOPT_FTP_ACCOUNT CURLOPT_FTP_ALTERNATIVE_TO_USER CURLOPT_HAPROXY_CLIENT_IP CURLOPT_HSTS CURLOPT_INTERFACE CURLOPT_ISSUERCERT CURLOPT_KEYPASSWD CURLOPT_KRBLEVEL CURLOPT_LOGIN_OPTIONS CURLOPT_MAIL_AUTH CURLOPT_MAIL_FROM CURLOPT_NETRC_FILE CURLOPT_NOPROXY CURLOPT_PASSWORD CURLOPT_PINNEDPUBLICKEY CURLOPT_PRE_PROXY CURLOPT_PROTOCOLS_STR CURLOPT_PROXY CURLOPT_PROXYPASSWORD CURLOPT_PROXYUSERNAME CURLOPT_PROXYUSERPWD CURLOPT_PROXY_CAINFO CURLOPT_PROXY_CAPATH CURLOPT_PROXY_CRLFILE CURLOPT_PROXY_ISSUERCERT CURLOPT_PROXY_KEYPASSWD CURLOPT_PROXY_PINNEDPUBLICKEY CURLOPT_PROXY_SERVICE_NAME CURLOPT_PROXY_SSLCERT CURLOPT_PROXY_SSLCERTTYPE CURLOPT_PROXY_SSLKEY CURLOPT_PROXY_SSLKEYTYPE CURLOPT_PROXY_SSL_CIPHER_LIST CURLOPT_PROXY_TLS13_CIPHERS CURLOPT_PROXY_TLSAUTH_PASSWORD CURLOPT_PROXY_TLSAUTH_TYPE CURLOPT_PROXY_TLSAUTH_USERNAME CURLOPT_RANDOM_FILE CURLOPT_RANGE CURLOPT_REDIR_PROTOCOLS_STR CURLOPT_REFERER CURLOPT_REQUEST_TARGET CURLOPT_RTSP_SESSION_ID CURLOPT_RTSP_STREAM_URI CURLOPT_RTSP_TRANSPORT CURLOPT_SASL_AUTHZID CURLOPT_SERVICE_NAME CURLOPT_SOCKS5_GSSAPI_SERVICE CURLOPT_SSH_HOST_PUBLIC_KEY_MD5 CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 CURLOPT_SSH_KNOWNHOSTS CURLOPT_SSH_PRIVATE_KEYFILE CURLOPT_SSH_PUBLIC_KEYFILE CURLOPT_SSLCERT CURLOPT_SSLCERTTYPE CURLOPT_SSLENGINE CURLOPT_SSLKEY CURLOPT_SSLKEYTYPE CURLOPT_SSL_CIPHER_LIST CURLOPT_SSL_EC_CURVES CURLOPT_TLS13_CIPHERS CURLOPT_TLSAUTH_PASSWORD CURLOPT_TLSAUTH_TYPE CURLOPT_TLSAUTH_USERNAME CURLOPT_UNIX_SOCKET_PATH CURLOPT_URL CURLOPT_USERAGENT CURLOPT_USERNAME CURLOPT_USERPWD CURLOPT_XOAUTH2_BEARER All blob options are also supported. In all other cases, it ignores the ccsid parameter and behaves as curl_easy_setopt(). Note that CURLOPT_ERRORBUFFER is not in the list above, since it gives the address of an (empty) character buffer, not the address of a string. CURLOPT_POSTFIELDS stores the address of static binary data (of type void *) and thus is not converted. If CURLOPT_COPYPOSTFIELDS is issued after CURLOPT_POSTFIELDSIZE != -1, the data size is adjusted according to the CCSID conversion result length. _ curl_formadd_ccsid() In the variable argument list, string pointers should be followed by a (long) CCSID for the following options: CURLFORM_BUFFER CURLFORM_CONTENTTYPE CURLFORM_COPYCONTENTS CURLFORM_COPYNAME CURLFORM_FILE CURLFORM_FILECONTENT CURLFORM_FILENAME CURLFORM_PTRNAME If taken from an argument array, an additional array entry must follow each entry containing one of the above option. This additional entry holds the CCSID in its value field, and the option field is meaningless. It is not possible to have a string pointer and its CCSID across a function parameter/array boundary. Please note that CURLFORM_PTRCONTENTS and CURLFORM_BUFFERPTR are considered unconvertible strings and thus are NOT followed by a CCSID. _ curl_easy_getinfo_ccsid() The following options are followed by a 'char * *' and a CCSID. Unlike curl_easy_getinfo(), the value returned in the pointer should be released with curl_free() after use: CURLINFO_CONTENT_TYPE CURLINFO_EFFECTIVE_URL CURLINFO_FTP_ENTRY_PATH CURLINFO_LOCAL_IP CURLINFO_PRIMARY_IP CURLINFO_REDIRECT_URL CURLINFO_REFERER CURLINFO_RTSP_SESSION_ID CURLINFO_SCHEME Likewise, the following options are followed by a struct curl_slist * * and a CCSID. CURLINFO_COOKIELIST CURLINFO_SSL_ENGINES Lists returned should be released with curl_slist_free_all() after use. Option CURLINFO_CERTINFO is followed by a struct curl_certinfo * * and a CCSID. Returned structures should be freed with curl_certinfo_free_all() after use. Other options are processed like in curl_easy_getinfo(). _ curl_easy_strerror_ccsid(), curl_multi_strerror_ccsid(), curl_share_strerror_ccsid() and curl_url_strerror_ccsid() work as their non-ccsid version and return a string encoded in the additional ccsid parameter. These strings belong to libcurl and may not be freed by the caller. A subsequent call to the same procedure in the same thread invalidates the previous result. _ curl_pushheader_bynum_cssid() and curl_pushheader_byname_ccsid() Although the prototypes are self-explanatory, the returned string pointer should be released with curl_free() after use, as opposite to the non-ccsid versions of these procedures. Please note that HTTP2 is not (yet) implemented on OS/400, thus these functions will always return NULL. _ curl_easy_option_by_name_ccsid() returns a pointer to an untranslated option metadata structure. As each curl_easyoption structure holds the option name in ASCII, the curl_easy_option_get_name_ccsid() function allows getting it in any supported ccsid. However the caller should release the returned pointer with curl_free() after use. _ curl_easy_header_ccsid() works as its non-CCSID counterpart but requires an additional ccsid parameter specifying the name parameter encoding. The output hout parameter is kept in libcurl's encoding and should not be altered. _ curl_from_ccsid() and curl_to_ccsid() are string encoding conversion functions between ASCII (latin1) and the given CCSID. The first parameter is the source string, the second is the CCSID and the returned value is a pointer to the dynamically allocated string. These functions do not impact on Curl's behavior and are only provided for user convenience. After use, returned values must be released with curl_free(). Standard compilation environment does support neither autotools nor make; in fact, very few common utilities are available. As a consequence, the config-os400.h has been coded manually and the compilation scripts are a set of shell scripts stored in subdirectory packages/OS400. The test environment is currently not supported on OS/400. Protocols currently implemented on OS/400: _ DICT _ FILE _ FTP _ FTPS _ FTP with secure transmission _ GOPHER _ HTTP _ HTTPS _ IMAP _ IMAPS _ IMAP with secure transmission _ LDAP _ POP3 _ POP3S _ POP3 with secure transmission _ RTSP _ SCP if libssh2 is enabled _ SFTP if libssh2 is enabled _ SMTP _ SMTPS _ SMTP with secure transmission _ TELNET _ TFTP Compiling on OS/400: These instructions targets people who knows about OS/400, compiling, IFS and archive extraction. Do not ask questions about these subjects if you're not familiar with. _ As a prerequisite, QADRT development environment must be installed. For more information on downloading and installing the QADRT development kit, please see https://www.ibm.com/support/pages/node/6258183 _ If data compression has to be supported, ZLIB development environment must be installed. _ Likewise, if SCP and SFTP protocols have to be compiled in, LIBSSH2 developent environment must be installed. _ Install the curl source directory in IFS. Do NOT install it in the installation target directory (which defaults to /curl). _ Enter Qshell (QSH, not PASE) _ Change current directory to the curl installation directory _ Change current directory to ./packages/OS400 - If you want to change the default configuration parameters like debug info generation, optimization level, listing option, target library, ZLIB/LIBSSH2 availability and location, etc., copy file config400.default to config400.override and edit the latter. Do not edit the original default file as it might be overwritten by a subsequent source installation. _ Copy any file in the current directory to makelog (i.e.: cp initscript.sh makelog): this is intended to create the makelog file with an ASCII CCSID! _ Enter the command "sh makefile.sh > makelog 2>&1" _ Examine the makelog file to check for compilation errors. CZM0383 warnings on C or system standard API come from QADRT inlining and can safely be ignored. Without configuration parameters override, this will produce the following OS/400 objects: _ Library CURL. All other objects will be stored in this library. _ Modules for all libcurl units. _ Binding directory CURL_A, to be used at calling program link time for statically binding the modules (specify BNDSRVPGM(QADRTTS QGLDCLNT QGLDBRDR) when creating a program using CURL_A). _ Service program CURL., where is extracted from the lib/Makefile.am VERSION variable. To be used at calling program run-time when this program has dynamically bound curl at link time. _ Binding directory CURL. To be used to dynamically bind libcurl when linking a calling program. - CLI tool bound program CURL. - CLI command CURL. _ Source file H. It contains all the include members needed to compile a C/C++ module using libcurl, and an ILE/RPG /copy member for support in this language. _ Standard C/C++ libcurl include members in file H. _ CCSIDCURL member in file H. This defines the non-standard EBCDIC wrappers for C and C++. _ CURL.INC member in file H. This defines everything needed by an ILE/RPG program using libcurl. _ IFS directory /curl/include/curl containing the C header files for IFS source C/C++ compilation and curl.inc.rpgle for IFS source ILE/RPG compilation. - IFS link /curl/bin/curl to CLI tool program. Special programming consideration: QADRT being used, the following points must be considered: _ If static binding is used, service program QADRTTS must be linked too. _ The EBCDIC CCSID used by QADRT is 37 by default, NOT THE JOB'S CCSID. If another EBCDIC CCSID is required, it must be set via a locale through a call to setlocale_a (QADRT's setlocale() ASCII wrapper) with category LC_ALL or LC_CTYPE, or by setting environment variable QADRT_ENV_LOCALE to the locale object path before executing the program. _ Do not use original source include files unless you know what you are doing. Use the installed members instead (in /QSYS.LIB/CURL.LIB/H.FILE and /curl/include/curl). ILE/RPG support: Since most of the ILE OS/400 programmers use ILE/RPG exclusively, a definition /INCLUDE member is provided for this language. To include all libcurl definitions in an ILE/RPG module, line h bnddir('CURL/CURL') must figure in the program header, and line d/include curl/h,curl.inc in the global data section of the module's source code. No vararg procedure support exists in ILE/RPG: for this reason, the following considerations apply: _ Procedures curl_easy_setopt_long(), curl_easy_setopt_object(), curl_easy_setopt_function(), curl_easy_setopt_offset() and curl_easy_setopt_blob() are all alias prototypes to curl_easy_setopt(), but with different parameter lists. _ Procedures curl_easy_getinfo_string(), curl_easy_getinfo_long(), curl_easy_getinfo_double(), curl_easy_getinfo_slist(), curl_easy_getinfo_ptr(), curl_easy_getinfo_socket() and curl_easy_getinfo_off_t() are all alias prototypes to curl_easy_getinfo(), but with different parameter lists. _ Procedures curl_multi_setopt_long(), curl_multi_setopt_object(), curl_multi_setopt_function() and curl_multi_setopt_offset() are all alias prototypes to curl_multi_setopt(), but with different parameter lists. _ Procedures curl_share_setopt_int(), curl_share_setopt_ptr() and curl_share_setopt_proc() are all alias prototypes to curl_share_setopt, but with different parameter lists. _ Procedure curl_easy_setopt_blob_ccsid() is an alias of curl_easy_setopt_ccsid() supporting blob encoding conversion. _ The prototype of procedure curl_formadd() allows specifying a pointer option and the CURLFORM_END option. This makes possible to use an option array without any additional definition. If some specific incompatible argument list is used in the ILE/RPG program, the latter must define a specialised alias. The same applies to curl_formadd_ccsid() too. _ Since V7R4M0, procedure overloading is used to emulate limited "vararg-like" definitions of curl_easy_setopt(), curl_multi_setopt(), curl_share_setopt() and curl_easy_getinfo(). Blob and CCSID alternatives are NOT included in overloading. Since RPG cannot cast a long to a pointer, procedure curl_form_long_value() is provided for that purpose: this allows storing a long value in the curl_forms array. Please note the form API is deprecated and the MIME API should be used instead. CLI tool: The build system provides it as a bound program, an IFS link to it and a simple CL command. The latter however is not able to provide a different parameter for each option since there are too many of those; instead, parameters are entered in a single field subject to quoting and escaping, in the same form as expected by the standard CLI program. Care must be taken about the program output encoding: by default, it is sent to the standard output and is thus subject to transcoding. It is therefore recommended to use option "--output" to redirect output to a specific IFS file. Similar problems may occur about the standard input encoding.