1.\"- 2.\" Copyright (c) 1998-2004 Dag-Erling Co�dan Sm�rgrav 3.\" Copyright (c) 2010 Joerg Sonnenberger <joerg@NetBSD.org> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD: fetch.3,v 1.64 2007/12/18 11:03:26 des Exp $ 28.\" $NetBSD: fetch.3,v 1.5 2024/02/02 22:19:05 christos Exp $ 29.\" 30.Dd December 22, 2023 31.Dt FETCH 3 32.Os 33.Sh NAME 34.Nm fetchMakeURL , 35.Nm fetchParseURL , 36.Nm fetchCopyURL , 37.Nm fetchFreeURL , 38.Nm fetchXGetURL , 39.Nm fetchGetURL , 40.Nm fetchPutURL , 41.Nm fetchStatURL , 42.Nm fetchListURL , 43.Nm fetchXGet , 44.Nm fetchGet , 45.Nm fetchPut , 46.Nm fetchStat , 47.Nm fetchList , 48.Nm fetchXGetFile , 49.Nm fetchGetFile , 50.Nm fetchPutFile , 51.Nm fetchStatFile , 52.Nm fetchListFile , 53.Nm fetchXGetHTTP , 54.Nm fetchGetHTTP , 55.Nm fetchPutHTTP , 56.Nm fetchStatHTTP , 57.Nm fetchListHTTP , 58.Nm fetchXGetFTP , 59.Nm fetchGetFTP , 60.Nm fetchPutFTP , 61.Nm fetchStatFTP , 62.Nm fetchListFTP 63.Nm fetchInitURLList , 64.Nm fetchFreeURLList , 65.Nm fetchUnquotePath , 66.Nm fetchUnquoteFilename , 67.Nm fetchStringifyURL , 68.Nm fetchConnectionCacheInit , 69.Nm fetchConnectionCacheClose , 70.Nm fetch 71.Nd file transfer functions 72.Sh LIBRARY 73.Lb libfetch 74.Sh SYNOPSIS 75.In stdio.h 76.In fetch.h 77.Ft struct url * 78.Fn fetchMakeURL "const char *scheme" "const char *host" "int port" "const char *doc" "const char *user" "const char *pwd" 79.Ft struct url * 80.Fn fetchParseURL "const char *URL" 81.Ft struct url * 82.Fn fetchCopyURL "const struct url *u" 83.Ft void 84.Fn fetchFreeURL "struct url *u" 85.Ft fetchIO * 86.Fn fetchXGetURL "const char *URL" "struct url_stat *us" "const char *flags" 87.Ft fetchIO * 88.Fn fetchGetURL "const char *URL" "const char *flags" 89.Ft fetchIO * 90.Fn fetchPutURL "const char *URL" "const char *flags" 91.Ft int 92.Fn fetchStatURL "const char *URL" "struct url_stat *us" "const char *flags" 93.Ft int 94.Fn fetchListURL "struct url_list *list" "const char *URL" "const char *pattern" "const char *flags" 95.Ft fetchIO * 96.Fn fetchXGet "struct url *u" "struct url_stat *us" "const char *flags" 97.Ft fetchIO * 98.Fn fetchGet "struct url *u" "const char *flags" 99.Ft fetchIO * 100.Fn fetchPut "struct url *u" "const char *flags" 101.Ft int 102.Fn fetchStat "struct url *u" "struct url_stat *us" "const char *flags" 103.Ft int 104.Fn fetchList "struct url_list *list" "struct url *u" "const char *pattern" "const char *flags" 105.Ft fetchIO * 106.Fn fetchXGetFile "struct url *u" "struct url_stat *us" "const char *flags" 107.Ft fetchIO * 108.Fn fetchGetFile "struct url *u" "const char *flags" 109.Ft fetchIO * 110.Fn fetchPutFile "struct url *u" "const char *flags" 111.Ft int 112.Fn fetchStatFile "struct url *u" "struct url_stat *us" "const char *flags" 113.Ft int 114.Fn fetchListFile "struct url_list *list" "struct url *u" "const char *pattern" "const char *flags" 115.Ft fetchIO * 116.Fn fetchXGetHTTP "struct url *u" "struct url_stat *us" "const char *flags" 117.Ft fetchIO * 118.Fn fetchGetHTTP "struct url *u" "const char *flags" 119.Ft fetchIO * 120.Fn fetchPutHTTP "struct url *u" "const char *flags" 121.Ft int 122.Fn fetchStatHTTP "struct url *u" "struct url_stat *us" "const char *flags" 123.Ft int 124.Fn fetchListHTTP "struct url_list *list" "struct url *u" "const char *pattern" "const char *flags" 125.Ft fetchIO * 126.Fn fetchXGetFTP "struct url *u" "struct url_stat *us" "const char *flags" 127.Ft fetchIO * 128.Fn fetchGetFTP "struct url *u" "const char *flags" 129.Ft fetchIO * 130.Fn fetchPutFTP "struct url *u" "const char *flags" 131.Ft int 132.Fn fetchStatFTP "struct url *u" "struct url_stat *us" "const char *flags" 133.Ft int 134.Fn fetchListFTP "struct url_list *list" "struct url *u" "const char *pattern" "const char *flags" 135.Ft void 136.Fn fetchInitURLList "struct url_list *ul" 137.Ft int 138.Fn fetchAppendURLList "struct url_list *dst" "const struct url_list *src" 139.Ft void 140.Fn fetchFreeURLList "struct url_list *ul" 141.Ft char * 142.Fn fetchUnquotePath "struct url *u" 143.Ft char * 144.Fn fetchUnquoteFilename "struct url *u" 145.Ft char * 146.Fn fetchStringifyURL "const struct url *u" 147.Ft void 148.Fn fetchConnectionCacheInit "int global" "int per_host" 149.Ft void 150.Fn fetchConnectionCacheClose "void" 151.Sh DESCRIPTION 152These functions implement a high-level library for retrieving and 153uploading files using Uniform Resource Locators (URLs). 154.Pp 155.Fn fetchParseURL 156takes a URL in the form of a null-terminated string and splits it into 157its components function according to the Common Internet Scheme Syntax 158detailed in RFC 1738. 159A regular expression which produces this syntax is: 160.Bd -literal -offset indent 161\*[Lt]scheme\*[Gt]:(//(\*[Lt]user\*[Gt](:\*[Lt]pwd\*[Gt])?@)?\*[Lt]host\*[Gt](:\*[Lt]port\*[Gt])?)?/(\*[Lt]doc\*[Gt])? 162.Ed 163.Pp 164If the URL does not seem to begin with a scheme name, it is assumed to be a local path. 165Only absolute path names are accepted. 166.Pp 167Note that some components of the URL are not necessarily relevant to 168all URL schemes. 169For instance, the file scheme only needs the 170.Aq scheme 171and 172.Aq doc 173components. 174.Fn fetchParseURL 175quotes any unsafe character in the URL automatically. 176This is not done by 177.Fn fetchMakeURL . 178.Fn fetchCopyURL 179copies an existing 180.Vt url 181structure. 182.Pp 183.Fn fetchMakeURL , 184.Fn fetchParseURL , 185and 186.Fn fetchCopyURL 187return a pointer to a 188.Vt url 189structure, which is defined as follows in 190.In fetch.h : 191.Bd -literal 192#define URL_SCHEMELEN 16 193#define URL_USERLEN 256 194#define URL_PWDLEN 256 195#define URL_HOSTLEN 255 196 197struct url { 198 char scheme[URL_SCHEMELEN + 1]; 199 char user[URL_USERLEN + 1]; 200 char pwd[URL_PWDLEN + 1]; 201 char host[URL_HOSTLEN + 1]; 202 int port; 203 char *doc; 204 off_t offset; 205 size_t length; 206 time_t last_modified; 207}; 208.Ed 209.Pp 210The pointer returned by 211.Fn fetchMakeURL , 212.Fn fetchCopyURL , 213and 214.Fn fetchParseURL 215should be freed using 216.Fn fetchFreeURL . 217The size of 218.Vt struct URL 219is not part of the ABI. 220.Pp 221.Fn fetchXGetURL , 222.Fn fetchGetURL , 223and 224.Fn fetchPutURL 225constitute the recommended interface to the 226.Nm fetch 227library. 228They examine the URL passed to them to determine the transfer 229method, and call the appropriate lower-level functions to perform the 230actual transfer. 231.Fn fetchXGetURL 232also returns the remote document's metadata in the 233.Vt url_stat 234structure pointed to by the 235.Fa us 236argument. 237.Pp 238The 239.Fa flags 240argument is a string of characters which specify transfer options. 241The 242meaning of the individual flags is scheme-dependent, and is detailed 243in the appropriate section below. 244.Pp 245.Fn fetchStatURL 246attempts to obtain the requested document's metadata and fill in the 247structure pointed to by its second argument. 248The 249.Vt url_stat 250structure is defined as follows in 251.In fetch.h : 252.Bd -literal 253struct url_stat { 254 off_t size; 255 time_t atime; 256 time_t mtime; 257}; 258.Ed 259.Pp 260If the size could not be obtained from the server, the 261.Fa size 262field is set to \-1. 263If the modification time could not be obtained from the server, the 264.Fa mtime 265field is set to the epoch. 266If the access time could not be obtained from the server, the 267.Fa atime 268field is set to the modification time. 269.Pp 270.Fn fetchListURL 271attempts to list the contents of the directory pointed to by the URL provided. 272The pattern can be a simple glob-like expression as hint. 273Callers should not depend on the server to filter names. 274If successful, it appends the list of entries to the 275.Vt url_list 276structure. 277The 278.Vt url_list 279structure is defined as follows in 280.In fetch.h : 281.Bd -literal 282struct url_list { 283 size_t length; 284 size_t alloc_size; 285 struct url *urls; 286}; 287.Ed 288.Pp 289The list should be initialized by calling 290.Fn fetchInitURLList 291and the entries be freed by calling 292.Fn fetchFreeURLList . 293The function 294.Fn fetchAppendURLList 295can be used to append one URL lists to another. 296If the 297.Ql c 298(cache result) flag is specified, the library is allowed to internally 299cache the result. 300.Pp 301.Fn fetchStringifyURL 302returns the URL as string. 303.Fn fetchUnquotePath 304returns the path name part of the URL with any quoting undone. 305Query arguments and fragment identifiers are not included. 306.Fn fetchUnquoteFilename 307returns the last component of the path name as returned by 308.Fn fetchUnquotePath . 309.Fn fetchStringifyURL , 310.Fn fetchUnquotePath , 311and 312.Fn fetchUnquoteFilename 313return a string that should be deallocated with 314.Fn free 315after use. 316.Pp 317.Fn fetchConnectionCacheInit 318enables the connection cache. 319The first argument specifies the global limit on cached connections. 320The second argument specifies the host limit. 321Entries are considered to specify the same host, if the host name 322from the URL is identical, indepent of the address or address family. 323.Fn fetchConnectionCacheClose 324flushed the connection cache and closes all cached connections. 325.Pp 326.Fn fetchXGet , 327.Fn fetchGet , 328.Fn fetchPut , 329and 330.Fn fetchStat 331are similar to 332.Fn fetchXGetURL , 333.Fn fetchGetURL , 334.Fn fetchPutURL , 335and 336.Fn fetchStatURL , 337except that they expect a pre-parsed URL in the form of a pointer to 338a 339.Vt struct url 340rather than a string. 341.Pp 342All of the 343.Fn fetchXGetXXX , 344.Fn fetchGetXXX , 345and 346.Fn fetchPutXXX 347functions return a pointer to a stream which can be used to read or 348write data from or to the requested document, respectively. 349Note that 350although the implementation details of the individual access methods 351vary, it can generally be assumed that a stream returned by one of the 352.Fn fetchXGetXXX 353or 354.Fn fetchGetXXX 355functions is read-only, and that a stream returned by one of the 356.Fn fetchPutXXX 357functions is write-only. 358.Sh PROTOCOL INDEPENDENT FLAGS 359If the 360.Ql i 361(if-modified-since) flag is specified, the library will try to fetch 362the content only if it is newer than 363.Va last_modified . 364For HTTP an 365.Li If-Modified-Since 366HTTP header is sent. 367For FTP a 368.Li MTDM 369command is sent first and compared locally. 370For FILE the source file is compared. 371.Sh FILE SCHEME 372.Fn fetchXGetFile , 373.Fn fetchGetFile , 374and 375.Fn fetchPutFile 376provide access to documents which are files in a locally mounted file 377system. 378Only the 379.Aq document 380component of the URL is used. 381.Pp 382.Fn fetchXGetFile 383and 384.Fn fetchGetFile 385do not accept any flags. 386.Pp 387.Fn fetchPutFile 388accepts the 389.Ql a 390(append to file) flag. 391If that flag is specified, the data written to 392the stream returned by 393.Fn fetchPutFile 394will be appended to the previous contents of the file, instead of 395replacing them. 396.Sh FTP SCHEME 397.Fn fetchXGetFTP , 398.Fn fetchGetFTP , 399and 400.Fn fetchPutFTP 401implement the FTP protocol as described in RFC 959. 402.Pp 403By default 404.Nm libfetch 405will attempt to use passive mode first and only fallback to active mode 406if the server reports a syntax error. 407If the 408.Ql a 409(active) flag is specified, a passive connection is not tried and active mode 410is used directly. 411.Pp 412If the 413.Ql l 414(low) flag is specified, data sockets will be allocated in the low (or 415default) port range instead of the high port range (see 416.Xr ip 4 ) . 417.Pp 418If the 419.Ql d 420(direct) flag is specified, 421.Fn fetchXGetFTP , 422.Fn fetchGetFTP , 423and 424.Fn fetchPutFTP 425will use a direct connection even if a proxy server is defined. 426.Pp 427If no user name or password is given, the 428.Nm fetch 429library will attempt an anonymous login, with user name "anonymous" 430and password "anonymous@\*[Lt]hostname\*[Gt]". 431.Sh HTTP SCHEME 432The 433.Fn fetchXGetHTTP , 434.Fn fetchGetHTTP , 435and 436.Fn fetchPutHTTP 437functions implement the HTTP/1.1 protocol. 438With a little luck, there is 439even a chance that they comply with RFC 2616 and RFC 2617. 440.Pp 441If the 442.Ql d 443(direct) flag is specified, 444.Fn fetchXGetHTTP , 445.Fn fetchGetHTTP , 446and 447.Fn fetchPutHTTP 448will use a direct connection even if a proxy server is defined. 449.Pp 450Since there seems to be no good way of implementing the HTTP PUT 451method in a manner consistent with the rest of the 452.Nm fetch 453library, 454.Fn fetchPutHTTP 455is currently unimplemented. 456.Sh AUTHENTICATION 457Apart from setting the appropriate environment variables and 458specifying the user name and password in the URL or the 459.Vt struct url , 460the calling program has the option of defining an authentication 461function with the following prototype: 462.Pp 463.Ft int 464.Fn myAuthMethod "struct url *u" 465.Pp 466The callback function should fill in the 467.Fa user 468and 469.Fa pwd 470fields in the provided 471.Vt struct url 472and return 0 on success, or any other value to indicate failure. 473.Pp 474To register the authentication callback, simply set 475.Va fetchAuthMethod 476to point at it. 477The callback will be used whenever a site requires authentication and 478the appropriate environment variables are not set. 479.Pp 480This interface is experimental and may be subject to change. 481.Sh RETURN VALUES 482.Fn fetchParseURL 483returns a pointer to a 484.Vt struct url 485containing the individual components of the URL. 486If it is 487unable to allocate memory, or the URL is syntactically incorrect, 488.Fn fetchParseURL 489returns a 490.Dv NULL 491pointer. 492.Pp 493The 494.Fn fetchStat 495functions return 0 on success and \-1 on failure. 496.Pp 497All other functions return a stream pointer which may be used to 498access the requested document, or 499.Dv NULL 500if an error occurred. 501.Pp 502The following error codes are defined in 503.In fetch.h : 504.Bl -tag -width 18n 505.It Bq Er FETCH_ABORT 506Operation aborted 507.It Bq Er FETCH_AUTH 508Authentication failed 509.It Bq Er FETCH_DOWN 510Service unavailable 511.It Bq Er FETCH_EXISTS 512File exists 513.It Bq Er FETCH_FULL 514File system full 515.It Bq Er FETCH_INFO 516Informational response 517.It Bq Er FETCH_MEMORY 518Insufficient memory 519.It Bq Er FETCH_MOVED 520File has moved 521.It Bq Er FETCH_NETWORK 522Network error 523.It Bq Er FETCH_OK 524No error 525.It Bq Er FETCH_PROTO 526Protocol error 527.It Bq Er FETCH_RESOLV 528Resolver error 529.It Bq Er FETCH_SERVER 530Server error 531.It Bq Er FETCH_TEMP 532Temporary error 533.It Bq Er FETCH_TIMEOUT 534Operation timed out 535.It Bq Er FETCH_UNAVAIL 536File is not available 537.It Bq Er FETCH_UNKNOWN 538Unknown error 539.It Bq Er FETCH_URL 540Invalid URL 541.El 542.Pp 543The accompanying error message includes a protocol-specific error code 544and message, e.g.\& "File is not available (404 Not Found)" 545.Sh ENVIRONMENT 546.Bl -tag -width ".Ev FETCH_BIND_ADDRESS" 547.It Ev FETCH_BIND_ADDRESS 548Specifies a host name or IP address to which sockets used for outgoing 549connections will be bound. 550.It Ev FTP_LOGIN 551Default FTP login if none was provided in the URL. 552.It Ev FTP_PASSIVE_MODE 553If set to anything but 554.Ql no , 555forces the FTP code to use passive mode. 556.It Ev FTP_PASSWORD 557Default FTP password if the remote server requests one and none was 558provided in the URL. 559.It Ev FTP_PROXY 560URL of the proxy to use for FTP requests. 561The document part is ignored. 562FTP and HTTP proxies are supported; if no scheme is specified, FTP is 563assumed. 564If the proxy is an FTP proxy, 565.Nm libfetch 566will send 567.Ql user@host 568as user name to the proxy, where 569.Ql user 570is the real user name, and 571.Ql host 572is the name of the FTP server. 573.Pp 574If this variable is set to an empty string, no proxy will be used for 575FTP requests, even if the 576.Ev HTTP_PROXY 577variable is set. 578.It Ev ftp_proxy 579Same as 580.Ev FTP_PROXY , 581for compatibility. 582.It Ev HTTP_AUTH 583Specifies HTTP authorization parameters as a colon-separated list of 584items. 585The first and second item are the authorization scheme and realm 586respectively; further items are scheme-dependent. 587Currently, only basic authorization is supported. 588.Pp 589Basic authorization requires two parameters: the user name and 590password, in that order. 591.Pp 592This variable is only used if the server requires authorization and 593no user name or password was specified in the URL. 594.It Ev HTTP_PROXY 595URL of the proxy to use for HTTP requests. 596The document part is ignored. 597Only HTTP proxies are supported for HTTP requests. 598If no port number is specified, the default is 3128. 599.Pp 600Note that this proxy will also be used for FTP documents, unless the 601.Ev FTP_PROXY 602variable is set. 603.It Ev http_proxy 604Same as 605.Ev HTTP_PROXY , 606for compatibility. 607.It Ev HTTP_PROXY_AUTH 608Specifies authorization parameters for the HTTP proxy in the same 609format as the 610.Ev HTTP_AUTH 611variable. 612.Pp 613This variable is used if and only if connected to an HTTP proxy, and 614is ignored if a user and/or a password were specified in the proxy 615URL. 616.It Ev HTTP_REFERER 617Specifies the referrer URL to use for HTTP requests. 618If set to 619.Dq auto , 620the document URL will be used as referrer URL. 621.It Ev HTTP_USER_AGENT 622Specifies the User-Agent string to use for HTTP requests. 623This can be useful when working with HTTP origin or proxy servers that 624differentiate between user agents. 625.It Ev NETRC 626Specifies a file to use instead of 627.Pa ~/.netrc 628to look up login names and passwords for FTP sites. 629See 630.Xr ftp 1 631for a description of the file format. 632This feature is experimental. 633.It Ev NO_PROXY 634Either a single asterisk, which disables the use of proxies 635altogether, or a comma- or whitespace-separated list of hosts for 636which proxies should not be used. 637.It Ev no_proxy 638Same as 639.Ev NO_PROXY , 640for compatibility. 641.It Ev SSL_NO_VERIFY_PEER 642If defined, 643.Nm 644will skip validating certificates when fetching HTTPS URLs. 645.El 646.Sh EXAMPLES 647To access a proxy server on 648.Pa proxy.example.com 649port 8080, set the 650.Ev HTTP_PROXY 651environment variable in a manner similar to this: 652.Pp 653.Dl HTTP_PROXY=http://proxy.example.com:8080 654.Pp 655If the proxy server requires authentication, there are 656two options available for passing the authentication data. 657The first method is by using the proxy URL: 658.Pp 659.Dl HTTP_PROXY=http://\*[Lt]user\*[Gt]:\*[Lt]pwd\*[Gt]@proxy.example.com:8080 660.Pp 661The second method is by using the 662.Ev HTTP_PROXY_AUTH 663environment variable: 664.Bd -literal -offset indent 665HTTP_PROXY=http://proxy.example.com:8080 666HTTP_PROXY_AUTH=basic:*:\*[Lt]user\*[Gt]:\*[Lt]pwd\*[Gt] 667.Ed 668.Pp 669To disable the use of a proxy for an HTTP server running on the local 670host, define 671.Ev NO_PROXY 672as follows: 673.Bd -literal -offset indent 674NO_PROXY=localhost,127.0.0.1 675.Ed 676.Sh SEE ALSO 677.\" .Xr fetch 1 , 678.\" .Xr ftpio 3 , 679.Xr ftp 1 , 680.Xr ip 4 681.Rs 682.%A J. Postel 683.%A J. K. Reynolds 684.%D October 1985 685.%B File Transfer Protocol 686.%O RFC 959 687.Re 688.Rs 689.%A P. Deutsch 690.%A A. Emtage 691.%A A. Marine 692.%D May 1994 693.%T How to Use Anonymous FTP 694.%O RFC 1635 695.Re 696.Rs 697.%A T. Berners-Lee 698.%A L. Masinter 699.%A M. McCahill 700.%D December 1994 701.%T Uniform Resource Locators (URL) 702.%O RFC 1738 703.Re 704.Rs 705.%A R. Fielding 706.%A J. Gettys 707.%A J. Mogul 708.%A H. Frystyk 709.%A L. Masinter 710.%A P. Leach 711.%A T. Berners-Lee 712.%D January 1999 713.%B Hypertext Transfer Protocol -- HTTP/1.1 714.%O RFC 2616 715.Re 716.Rs 717.%A J. Franks 718.%A P. Hallam-Baker 719.%A J. Hostetler 720.%A S. Lawrence 721.%A P. Leach 722.%A A. Luotonen 723.%A L. Stewart 724.%D June 1999 725.%B HTTP Authentication: Basic and Digest Access Authentication 726.%O RFC 2617 727.Re 728.Sh HISTORY 729The 730.Nm fetch 731library first appeared in 732.Fx 3.0 . 733.Sh AUTHORS 734.An -nosplit 735The 736.Nm fetch 737library was mostly written by 738.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org 739with numerous suggestions from 740.An Jordan K. Hubbard Aq Mt jkh@FreeBSD.org , 741.An Eugene Skepner Aq Mt eu@qub.com 742and other 743.Fx 744developers. 745It replaces the older 746.Nm ftpio 747library written by 748.An Poul-Henning Kamp Aq Mt phk@FreeBSD.org 749and 750.An Jordan K. Hubbard Aq Mt jkh@FreeBSD.org . 751.Pp 752This manual page was written by 753.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org . 754.Sh BUGS 755Some parts of the library are not yet implemented. 756The most notable 757examples of this are 758.Fn fetchPutHTTP 759and FTP proxy support. 760.Pp 761There is no way to select a proxy at run-time other than setting the 762.Ev HTTP_PROXY 763or 764.Ev FTP_PROXY 765environment variables as appropriate. 766.Pp 767.Nm libfetch 768does not understand or obey 305 (Use Proxy) replies. 769.Pp 770Error numbers are unique only within a certain context; the error 771codes used for FTP and HTTP overlap, as do those used for resolver and 772system errors. 773For instance, error code 202 means "Command not 774implemented, superfluous at this site" in an FTP context and 775"Accepted" in an HTTP context. 776.Pp 777.Fn fetchStatFTP 778does not check that the result of an MDTM command is a valid date. 779.Pp 780The man page is incomplete, poorly written and produces badly 781formatted text. 782.Pp 783The error reporting mechanism is unsatisfactory. 784.Pp 785Some parts of the code are not fully reentrant. 786