1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632
|
/* The MIT License
Copyright (c) 2008 by Genome Research Ltd (GRL).
2010 by Attractive Chaos <attractor@live.co.uk>
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
/* Probably I will not do socket programming in the next few years and
therefore I decide to heavily annotate this file, for Linux and
Windows as well. -ac */
#include <time.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#ifndef _WIN32
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#endif
#include "knetfile.h"
/* In winsock.h, the type of a socket is SOCKET, which is: "typedef
* u_int SOCKET". An invalid SOCKET is: "(SOCKET)(~0)", or signed
* integer -1. In knetfile.c, I use "int" for socket type
* throughout. This should be improved to avoid confusion.
*
* In Linux/Mac, recv() and read() do almost the same thing. You can see
* in the header file that netread() is simply an alias of read(). In
* Windows, however, they are different and using recv() is mandatory.
*/
/* This function tests if the file handler is ready for reading (or
* writing if is_read==0). */
static int socket_wait(int fd, int is_read)
{
fd_set fds, *fdr = 0, *fdw = 0;
struct timeval tv;
int ret;
tv.tv_sec = 5; tv.tv_usec = 0; // 5 seconds time out
FD_ZERO(&fds);
FD_SET(fd, &fds);
if (is_read) fdr = &fds;
else fdw = &fds;
ret = select(fd+1, fdr, fdw, 0, &tv);
#ifndef _WIN32
if (ret == -1) perror("select");
#else
if (ret == 0)
fprintf(stderr, "select time-out\n");
else if (ret == SOCKET_ERROR)
fprintf(stderr, "select: %d\n", WSAGetLastError());
#endif
return ret;
}
#ifndef _WIN32
/* This function does not work with Windows due to the lack of
* getaddrinfo() in winsock. It is addapted from an example in "Beej's
* Guide to Network Programming" (http://beej.us/guide/bgnet/). */
static int socket_connect(const char *host, const char *port)
{
#define __err_connect(func) do { perror(func); freeaddrinfo(res); return -1; } while (0)
int on = 1, fd;
struct linger lng = { 0, 0 };
struct addrinfo hints, *res = 0;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
/* In Unix/Mac, getaddrinfo() is the most convenient way to get
* server information. */
if (getaddrinfo(host, port, &hints, &res) != 0) __err_connect("getaddrinfo");
if ((fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) __err_connect("socket");
/* The following two setsockopt() are used by ftplib
* (http://nbpfaus.net/~pfau/ftplib/). I am not sure if they
* necessary. */
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) __err_connect("setsockopt");
if (setsockopt(fd, SOL_SOCKET, SO_LINGER, &lng, sizeof(lng)) == -1) __err_connect("setsockopt");
if (connect(fd, res->ai_addr, res->ai_addrlen) != 0) __err_connect("connect");
freeaddrinfo(res);
return fd;
}
#else
/* MinGW's printf has problem with "%lld" */
char *int64tostr(char *buf, int64_t x)
{
int cnt;
int i = 0;
do {
buf[i++] = '0' + x % 10;
x /= 10;
} while (x);
buf[i] = 0;
for (cnt = i, i = 0; i < cnt/2; ++i) {
int c = buf[i]; buf[i] = buf[cnt-i-1]; buf[cnt-i-1] = c;
}
return buf;
}
int64_t strtoint64(const char *buf)
{
int64_t x;
for (x = 0; *buf != '\0'; ++buf)
x = x * 10 + ((int64_t) *buf - 48);
return x;
}
/* In windows, the first thing is to establish the TCP connection. */
int knet_win32_init()
{
WSADATA wsaData;
return WSAStartup(MAKEWORD(2, 2), &wsaData);
}
void knet_win32_destroy()
{
WSACleanup();
}
/* A slightly modfied version of the following function also works on
* Mac (and presummably Linux). However, this function is not stable on
* my Mac. It sometimes works fine but sometimes does not. Therefore for
* non-Windows OS, I do not use this one. */
static SOCKET socket_connect(const char *host, const char *port)
{
#define __err_connect(func) \
do { \
fprintf(stderr, "%s: %d\n", func, WSAGetLastError()); \
return -1; \
} while (0)
int on = 1;
SOCKET fd;
struct linger lng = { 0, 0 };
struct sockaddr_in server;
struct hostent *hp = 0;
// open socket
if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET) __err_connect("socket");
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char*)&on, sizeof(on)) == -1) __err_connect("setsockopt");
if (setsockopt(fd, SOL_SOCKET, SO_LINGER, (char*)&lng, sizeof(lng)) == -1) __err_connect("setsockopt");
// get host info
if (isalpha(host[0])) hp = gethostbyname(host);
else {
struct in_addr addr;
addr.s_addr = inet_addr(host);
hp = gethostbyaddr((char*)&addr, 4, AF_INET);
}
if (hp == 0) __err_connect("gethost");
// connect
server.sin_addr.s_addr = *((unsigned long*)hp->h_addr);
server.sin_family= AF_INET;
server.sin_port = htons(atoi(port));
if (connect(fd, (struct sockaddr*)&server, sizeof(server)) != 0) __err_connect("connect");
// freehostent(hp); // strangely in MSDN, hp is NOT freed (memory leak?!)
return fd;
}
#endif
static off_t my_netread(int fd, void *buf, off_t len)
{
off_t rest = len, curr, l = 0;
/* recv() and read() may not read the required length of data with
* one call. They have to be called repeatedly. */
while (rest) {
if (socket_wait(fd, 1) <= 0) break; // socket is not ready for reading
curr = netread(fd, buf + l, rest);
/* According to the glibc manual, section 13.2, a zero returned
* value indicates end-of-file (EOF), which should mean that
* read() will not return zero if EOF has not been met but data
* are not immediately available. */
if (curr == 0) break;
l += curr; rest -= curr;
}
return l;
}
/*************************
* FTP specific routines *
*************************/
static int kftp_get_response(knetFile *ftp)
{
#ifndef _WIN32
unsigned char c;
#else
char c;
#endif
int n = 0;
char *p;
if (socket_wait(ftp->ctrl_fd, 1) <= 0) return 0;
while (netread(ftp->ctrl_fd, &c, 1)) { // FIXME: this is *VERY BAD* for unbuffered I/O
//fputc(c, stderr);
if (n >= ftp->max_response) {
ftp->max_response = ftp->max_response? ftp->max_response<<1 : 256;
ftp->response = realloc(ftp->response, ftp->max_response);
}
ftp->response[n++] = c;
if (c == '\n') {
if (n >= 4 && isdigit(ftp->response[0]) && isdigit(ftp->response[1]) && isdigit(ftp->response[2])
&& ftp->response[3] != '-') break;
n = 0;
continue;
}
}
if (n < 2) return -1;
ftp->response[n-2] = 0;
return strtol(ftp->response, &p, 0);
}
static int kftp_send_cmd(knetFile *ftp, const char *cmd, int is_get)
{
if (socket_wait(ftp->ctrl_fd, 0) <= 0) return -1; // socket is not ready for writing
netwrite(ftp->ctrl_fd, cmd, strlen(cmd));
return is_get? kftp_get_response(ftp) : 0;
}
static int kftp_pasv_prep(knetFile *ftp)
{
char *p;
int v[6];
kftp_send_cmd(ftp, "PASV\r\n", 1);
for (p = ftp->response; *p && *p != '('; ++p);
if (*p != '(') return -1;
++p;
sscanf(p, "%d,%d,%d,%d,%d,%d", &v[0], &v[1], &v[2], &v[3], &v[4], &v[5]);
memcpy(ftp->pasv_ip, v, 4 * sizeof(int));
ftp->pasv_port = (v[4]<<8&0xff00) + v[5];
return 0;
}
static int kftp_pasv_connect(knetFile *ftp)
{
char host[80], port[10];
if (ftp->pasv_port == 0) {
fprintf(stderr, "[kftp_pasv_connect] kftp_pasv_prep() is not called before hand.\n");
return -1;
}
sprintf(host, "%d.%d.%d.%d", ftp->pasv_ip[0], ftp->pasv_ip[1], ftp->pasv_ip[2], ftp->pasv_ip[3]);
sprintf(port, "%d", ftp->pasv_port);
ftp->fd = socket_connect(host, port);
if (ftp->fd == -1) return -1;
return 0;
}
int kftp_connect(knetFile *ftp)
{
ftp->ctrl_fd = socket_connect(ftp->host, ftp->port);
if (ftp->ctrl_fd == -1) return -1;
kftp_get_response(ftp);
kftp_send_cmd(ftp, "USER anonymous\r\n", 1);
kftp_send_cmd(ftp, "PASS kftp@\r\n", 1);
kftp_send_cmd(ftp, "TYPE I\r\n", 1);
return 0;
}
int kftp_reconnect(knetFile *ftp)
{
if (ftp->ctrl_fd != -1) {
netclose(ftp->ctrl_fd);
ftp->ctrl_fd = -1;
}
netclose(ftp->fd);
ftp->fd = -1;
return kftp_connect(ftp);
}
// initialize ->type, ->host, ->retr and ->size
knetFile *kftp_parse_url(const char *fn, const char *mode)
{
knetFile *fp;
char *p;
int l;
if (strstr(fn, "ftp://") != fn) return 0;
for (p = (char*)fn + 6; *p && *p != '/'; ++p);
if (*p != '/') return 0;
l = p - fn - 6;
fp = calloc(1, sizeof(knetFile));
fp->type = KNF_TYPE_FTP;
fp->fd = -1;
/* the Linux/Mac version of socket_connect() also recognizes a port
* like "ftp", but the Windows version does not. */
fp->port = strdup("21");
fp->host = calloc(l + 1, 1);
if (strchr(mode, 'c')) fp->no_reconnect = 1;
strncpy(fp->host, fn + 6, l);
fp->retr = calloc(strlen(p) + 8, 1);
sprintf(fp->retr, "RETR %s\r\n", p);
fp->size_cmd = calloc(strlen(p) + 8, 1);
sprintf(fp->size_cmd, "SIZE %s\r\n", p);
fp->seek_offset = 0;
return fp;
}
// place ->fd at offset off
int kftp_connect_file(knetFile *fp)
{
int ret;
long long file_size;
if (fp->fd != -1) {
netclose(fp->fd);
if (fp->no_reconnect) kftp_get_response(fp);
}
kftp_pasv_prep(fp);
kftp_send_cmd(fp, fp->size_cmd, 1);
#ifndef _WIN32
if ( sscanf(fp->response,"%*d %lld", &file_size) != 1 )
{
fprintf(stderr,"[kftp_connect_file] %s\n", fp->response);
return -1;
}
#else
const char *p = fp->response;
while (*p != ' ') ++p;
while (*p < '0' || *p > '9') ++p;
file_size = strtoint64(p);
#endif
fp->file_size = file_size;
if (fp->offset>=0) {
char tmp[32];
#ifndef _WIN32
sprintf(tmp, "REST %lld\r\n", (long long)fp->offset);
#else
strcpy(tmp, "REST ");
int64tostr(tmp + 5, fp->offset);
strcat(tmp, "\r\n");
#endif
kftp_send_cmd(fp, tmp, 1);
}
kftp_send_cmd(fp, fp->retr, 0);
kftp_pasv_connect(fp);
ret = kftp_get_response(fp);
if (ret != 150) {
fprintf(stderr, "[kftp_connect_file] %s\n", fp->response);
netclose(fp->fd);
fp->fd = -1;
return -1;
}
fp->is_ready = 1;
return 0;
}
/**************************
* HTTP specific routines *
**************************/
knetFile *khttp_parse_url(const char *fn, const char *mode)
{
knetFile *fp;
char *p, *proxy, *q;
int l;
if (strstr(fn, "http://") != fn) return 0;
// set ->http_host
for (p = (char*)fn + 7; *p && *p != '/'; ++p);
l = p - fn - 7;
fp = calloc(1, sizeof(knetFile));
fp->http_host = calloc(l + 1, 1);
strncpy(fp->http_host, fn + 7, l);
fp->http_host[l] = 0;
for (q = fp->http_host; *q && *q != ':'; ++q);
if (*q == ':') *q++ = 0;
// get http_proxy
proxy = getenv("http_proxy");
// set ->host, ->port and ->path
if (proxy == 0) {
fp->host = strdup(fp->http_host); // when there is no proxy, server name is identical to http_host name.
fp->port = strdup(*q? q : "80");
fp->path = strdup(*p? p : "/");
} else {
fp->host = (strstr(proxy, "http://") == proxy)? strdup(proxy + 7) : strdup(proxy);
for (q = fp->host; *q && *q != ':'; ++q);
if (*q == ':') *q++ = 0;
fp->port = strdup(*q? q : "80");
fp->path = strdup(fn);
}
fp->type = KNF_TYPE_HTTP;
fp->ctrl_fd = fp->fd = -1;
fp->seek_offset = 0;
return fp;
}
int khttp_connect_file(knetFile *fp)
{
int ret, l = 0;
char *buf, *p;
if (fp->fd != -1) netclose(fp->fd);
fp->fd = socket_connect(fp->host, fp->port);
buf = calloc(0x10000, 1); // FIXME: I am lazy... But in principle, 64KB should be large enough.
l += sprintf(buf + l, "GET %s HTTP/1.0\r\nHost: %s\r\n", fp->path, fp->http_host);
l += sprintf(buf + l, "Range: bytes=%lld-\r\n", (long long)fp->offset);
l += sprintf(buf + l, "\r\n");
netwrite(fp->fd, buf, l);
l = 0;
while (netread(fp->fd, buf + l, 1)) { // read HTTP header; FIXME: bad efficiency
if (buf[l] == '\n' && l >= 3)
if (strncmp(buf + l - 3, "\r\n\r\n", 4) == 0) break;
++l;
}
buf[l] = 0;
if (l < 14) { // prematured header
netclose(fp->fd);
fp->fd = -1;
return -1;
}
ret = strtol(buf + 8, &p, 0); // HTTP return code
if (ret == 200 && fp->offset>0) { // 200 (complete result); then skip beginning of the file
off_t rest = fp->offset;
while (rest) {
off_t l = rest < 0x10000? rest : 0x10000;
rest -= my_netread(fp->fd, buf, l);
}
} else if (ret != 206 && ret != 200) {
free(buf);
fprintf(stderr, "[khttp_connect_file] fail to open file (HTTP code: %d).\n", ret);
netclose(fp->fd);
fp->fd = -1;
return -1;
}
free(buf);
fp->is_ready = 1;
return 0;
}
/********************
* Generic routines *
********************/
knetFile *knet_open(const char *fn, const char *mode)
{
knetFile *fp = 0;
if (mode[0] != 'r') {
fprintf(stderr, "[kftp_open] only mode \"r\" is supported.\n");
return 0;
}
if (strstr(fn, "ftp://") == fn) {
fp = kftp_parse_url(fn, mode);
if (fp == 0) return 0;
if (kftp_connect(fp) == -1) {
knet_close(fp);
return 0;
}
kftp_connect_file(fp);
} else if (strstr(fn, "http://") == fn) {
fp = khttp_parse_url(fn, mode);
if (fp == 0) return 0;
khttp_connect_file(fp);
} else { // local file
#ifdef _WIN32
/* In windows, O_BINARY is necessary. In Linux/Mac, O_BINARY may
* be undefined on some systems, although it is defined on my
* Mac and the Linux I have tested on. */
int fd = open(fn, O_RDONLY | O_BINARY);
#else
int fd = open(fn, O_RDONLY);
#endif
if (fd == -1) {
perror("open");
return 0;
}
fp = (knetFile*)calloc(1, sizeof(knetFile));
fp->type = KNF_TYPE_LOCAL;
fp->fd = fd;
fp->ctrl_fd = -1;
}
if (fp && fp->fd == -1) {
knet_close(fp);
return 0;
}
return fp;
}
knetFile *knet_dopen(int fd, const char *mode)
{
knetFile *fp = (knetFile*)calloc(1, sizeof(knetFile));
fp->type = KNF_TYPE_LOCAL;
fp->fd = fd;
return fp;
}
off_t knet_read(knetFile *fp, void *buf, off_t len)
{
off_t l = 0;
if (fp->fd == -1) return 0;
if (fp->type == KNF_TYPE_FTP) {
if (fp->is_ready == 0) {
if (!fp->no_reconnect) kftp_reconnect(fp);
kftp_connect_file(fp);
}
} else if (fp->type == KNF_TYPE_HTTP) {
if (fp->is_ready == 0)
khttp_connect_file(fp);
}
if (fp->type == KNF_TYPE_LOCAL) { // on Windows, the following block is necessary; not on UNIX
off_t rest = len, curr;
while (rest) {
do {
curr = read(fp->fd, buf + l, rest);
} while (curr < 0 && EINTR == errno);
if (curr < 0) return -1;
if (curr == 0) break;
l += curr; rest -= curr;
}
} else l = my_netread(fp->fd, buf, len);
fp->offset += l;
return l;
}
off_t knet_seek(knetFile *fp, int64_t off, int whence)
{
if (whence == SEEK_SET && off == fp->offset) return 0;
if (fp->type == KNF_TYPE_LOCAL) {
/* Be aware that lseek() returns the offset after seeking,
* while fseek() returns zero on success. */
off_t offset = lseek(fp->fd, off, whence);
if (offset == -1) {
// Be silent, it is OK for knet_seek to fail when the file is streamed
// fprintf(stderr,"[knet_seek] %s\n", strerror(errno));
return -1;
}
fp->offset = offset;
return 0;
}
else if (fp->type == KNF_TYPE_FTP)
{
if (whence==SEEK_CUR)
fp->offset += off;
else if (whence==SEEK_SET)
fp->offset = off;
else if ( whence==SEEK_END)
fp->offset = fp->file_size+off;
fp->is_ready = 0;
return 0;
}
else if (fp->type == KNF_TYPE_HTTP)
{
if (whence == SEEK_END) { // FIXME: can we allow SEEK_END in future?
fprintf(stderr, "[knet_seek] SEEK_END is not supported for HTTP. Offset is unchanged.\n");
errno = ESPIPE;
return -1;
}
if (whence==SEEK_CUR)
fp->offset += off;
else if (whence==SEEK_SET)
fp->offset = off;
fp->is_ready = 0;
return 0;
}
errno = EINVAL;
fprintf(stderr,"[knet_seek] %s\n", strerror(errno));
return -1;
}
int knet_close(knetFile *fp)
{
if (fp == 0) return 0;
if (fp->ctrl_fd != -1) netclose(fp->ctrl_fd); // FTP specific
if (fp->fd != -1) {
/* On Linux/Mac, netclose() is an alias of close(), but on
* Windows, it is an alias of closesocket(). */
if (fp->type == KNF_TYPE_LOCAL) close(fp->fd);
else netclose(fp->fd);
}
free(fp->host); free(fp->port);
free(fp->response); free(fp->retr); // FTP specific
free(fp->path); free(fp->http_host); // HTTP specific
free(fp);
return 0;
}
#ifdef KNETFILE_MAIN
int main(void)
{
char *buf;
knetFile *fp;
int type = 4, l;
#ifdef _WIN32
knet_win32_init();
#endif
buf = calloc(0x100000, 1);
if (type == 0) {
fp = knet_open("knetfile.c", "r");
knet_seek(fp, 1000, SEEK_SET);
} else if (type == 1) { // NCBI FTP, large file
fp = knet_open("ftp://ftp.ncbi.nih.gov/1000genomes/ftp/data/NA12878/alignment/NA12878.chrom6.SLX.SRP000032.2009_06.bam", "r");
knet_seek(fp, 2500000000ll, SEEK_SET);
l = knet_read(fp, buf, 255);
} else if (type == 2) {
fp = knet_open("ftp://ftp.sanger.ac.uk/pub4/treefam/tmp/index.shtml", "r");
knet_seek(fp, 1000, SEEK_SET);
} else if (type == 3) {
fp = knet_open("http://www.sanger.ac.uk/Users/lh3/index.shtml", "r");
knet_seek(fp, 1000, SEEK_SET);
} else if (type == 4) {
fp = knet_open("http://www.sanger.ac.uk/Users/lh3/ex1.bam", "r");
knet_read(fp, buf, 10000);
knet_seek(fp, 20000, SEEK_SET);
knet_seek(fp, 10000, SEEK_SET);
l = knet_read(fp, buf+10000, 10000000) + 10000;
}
if (type != 4 && type != 1) {
knet_read(fp, buf, 255);
buf[255] = 0;
printf("%s\n", buf);
} else write(fileno(stdout), buf, l);
knet_close(fp);
free(buf);
return 0;
}
#endif
|