| /* vi: set sw=4 ts=4: */ |
| /* |
| * wget - retrieve a file using HTTP |
| * |
| * Chip Rosenthal |
| * Covad Communications |
| * <chip@laserlink.net> |
| */ |
| |
| #include "internal.h" |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <ctype.h> |
| #include <string.h> |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <netdb.h> |
| |
| |
| void parse_url(char *url, char **uri_host, int *uri_port, char **uri_path); |
| FILE *open_socket(char *host, int port); |
| char *gethdr(char *buf, size_t bufsiz, FILE *fp, int *istrunc); |
| |
| |
| int wget_main(int argc, char **argv) |
| { |
| FILE *sfp; /* socket to web server */ |
| char *uri_host, *uri_path; /* parsed from command line url */ |
| int uri_port; |
| char *s, buf[512]; |
| int n; |
| |
| char *fname_out = NULL; /* where to direct output (-O) */ |
| int do_continue = 0; /* continue a prev transfer (-c) */ |
| long beg_range = 0L; /* range at which continue begins */ |
| int got_clen = 0; /* got content-length: from server */ |
| long clen = 1L; /* the content length */ |
| |
| /* |
| * Crack command line. |
| */ |
| while ((n = getopt(argc, argv, "cO:")) != EOF) { |
| switch (n) { |
| case 'c': |
| ++do_continue; |
| break; |
| case 'O': |
| fname_out = optarg; |
| break; |
| default: |
| usage(wget_usage); |
| } |
| } |
| if (do_continue && !fname_out) |
| fatalError("wget: cannot specify continue (-c) without a filename (-O)\n"); |
| if (argc - optind != 1) |
| usage(wget_usage); |
| /* |
| * Parse url into components. |
| */ |
| parse_url(argv[optind], &uri_host, &uri_port, &uri_path); |
| |
| /* |
| * Open socket to server. |
| */ |
| sfp = open_socket(uri_host, uri_port); |
| |
| /* |
| * Open the output stream. |
| */ |
| if (fname_out != NULL) { |
| /* Check if the file is supposed to go to stdout */ |
| if (!strcmp(fname_out, "-") == 0) { |
| /* Nope -- so open the output file */ |
| if (freopen(fname_out, (do_continue ? "a" : "w"), stdout) == NULL) |
| fatalError("wget: freopen(%s): %s\n", fname_out, strerror(errno)); |
| } |
| } |
| |
| /* |
| * Determine where to start transfer. |
| */ |
| if (do_continue) { |
| struct stat sbuf; |
| if (fstat(fileno(stdout), &sbuf) < 0) |
| fatalError("wget: fstat(): %s\n", strerror(errno)); |
| if (sbuf.st_size > 0) |
| beg_range = sbuf.st_size; |
| else |
| do_continue = 0; |
| } |
| |
| /* |
| * Send HTTP request. |
| */ |
| fprintf(sfp, "GET %s HTTP/1.1\r\nHost: %s\r\n", uri_path, uri_host); |
| if (do_continue) |
| fprintf(sfp, "Range: bytes=%ld-\r\n", beg_range); |
| fputs("Connection: close\r\n\r\n", sfp); |
| |
| /* |
| * Retrieve HTTP response line and check for "200" status code. |
| */ |
| if (fgets(buf, sizeof(buf), sfp) == NULL) |
| fatalError("wget: no response from server\n"); |
| for (s = buf ; *s != '\0' && !isspace(*s) ; ++s) |
| ; |
| for ( ; isspace(*s) ; ++s) |
| ; |
| switch (atoi(s)) { |
| case 200: |
| if (!do_continue) |
| break; |
| fatalError("wget: cannot continue - server does not properly support ranges\n"); |
| case 206: |
| if (do_continue) |
| break; |
| /*FALLTHRU*/ |
| default: |
| fatalError("wget: server returned error: %s", buf); |
| } |
| |
| /* |
| * Retrieve HTTP headers. |
| */ |
| while ((s = gethdr(buf, sizeof(buf), sfp, &n)) != NULL) { |
| if (strcmp(buf, "content-length") == 0) { |
| clen = atol(s); |
| got_clen = 1; |
| continue; |
| } |
| if (strcmp(buf, "transfer-encoding") == 0) { |
| fatalError("wget: i do not do transfer encodings, server wants to do: %s\n", s); |
| continue; |
| } |
| } |
| |
| /* |
| * Retrieve HTTP body. |
| */ |
| while (clen > 0 && (n = fread(buf, 1, sizeof(buf), sfp)) > 0) { |
| fwrite(buf, 1, n, stdout); |
| if (got_clen) |
| clen -= n; |
| } |
| if (n == 0 && ferror(sfp)) |
| fatalError("wget: network read error: %s", strerror(errno)); |
| |
| exit(0); |
| } |
| |
| |
| void parse_url(char *url, char **uri_host, int *uri_port, char **uri_path) |
| { |
| char *s, *h; |
| |
| *uri_port = 80; |
| |
| if (strncmp(url, "http://", 7) != 0) |
| fatalError("wget: not an http url: %s\n", url); |
| |
| /* pull the host portion to the front of the buffer */ |
| for (s = url, h = url+7 ; *h != '/' ; ++h) { |
| if (*h == '\0') |
| fatalError("wget: cannot parse url: %s\n", url); |
| if (*h == ':') { |
| *uri_port = atoi(h+1); |
| *h = '\0'; |
| } |
| *s++ = *h; |
| } |
| *s = '\0'; |
| *uri_host = url; |
| *uri_path = h; |
| } |
| |
| |
| FILE *open_socket(char *host, int port) |
| { |
| struct sockaddr_in sin; |
| struct hostent *hp; |
| int fd; |
| FILE *fp; |
| |
| memzero(&sin, sizeof(sin)); |
| sin.sin_family = AF_INET; |
| if ((hp = (struct hostent *) gethostbyname(host)) == NULL) |
| fatalError("wget: cannot resolve %s\n", host); |
| memcpy(&sin.sin_addr, hp->h_addr_list[0], hp->h_length); |
| sin.sin_port = htons(port); |
| |
| /* |
| * Get the server onto a stdio stream. |
| */ |
| if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) |
| fatalError("wget: socket(): %s\n", strerror(errno)); |
| if (connect(fd, (struct sockaddr *) &sin, sizeof(sin)) < 0) |
| fatalError("wget: connect(%s): %s\n", host, strerror(errno)); |
| if ((fp = fdopen(fd, "r+")) == NULL) |
| fatalError("wget: fdopen(): %s\n", strerror(errno)); |
| |
| return fp; |
| } |
| |
| |
| char *gethdr(char *buf, size_t bufsiz, FILE *fp, int *istrunc) |
| { |
| char *s, *hdrval; |
| int c; |
| |
| *istrunc = 0; |
| |
| /* retrieve header line */ |
| if (fgets(buf, bufsiz, fp) == NULL) |
| return NULL; |
| |
| /* see if we are at the end of the headers */ |
| for (s = buf ; *s == '\r' ; ++s) |
| ; |
| if (s[0] == '\n') |
| return NULL; |
| |
| /* convert the header name to lower case */ |
| for (s = buf ; isalnum(*s) || *s == '-' ; ++s) |
| *s = tolower(*s); |
| |
| /* verify we are at the end of the header name */ |
| if (*s != ':') |
| fatalError("wget: bad header line: %s\n", buf); |
| |
| /* locate the start of the header value */ |
| for (*s++ = '\0' ; *s == ' ' || *s == '\t' ; ++s) |
| ; |
| hdrval = s; |
| |
| /* locate the end of header */ |
| while (*s != '\0' && *s != '\r' && *s != '\n') |
| ++s; |
| |
| /* end of header found */ |
| if (*s != '\0') { |
| *s = '\0'; |
| return hdrval; |
| } |
| |
| /* Rat! The buffer isn't big enough to hold the entire header value. */ |
| while (c = getc(fp), c != EOF && c != '\n') |
| ; |
| *istrunc = 1; |
| return hdrval; |
| } |
| |
| /* |
| Local Variables: |
| c-file-style: "linux" |
| c-basic-offset: 4 |
| tab-width: 4 |
| End: |
| */ |