%s

/* redirect - simple redirection CGI program ** ** Copyright © 1995 by Jef Poskanzer . ** All rights reserved. ** ** Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions ** are met: ** 1. Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** 2. Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in the ** documentation and/or other materials provided with the distribution. ** ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ** ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF ** SUCH DAMAGE. */ /* Three steps to set up a redirection: ** 1. Make sure your web server is set up to allow CGI programs. ** 2. Make a symbolic link from the file you want to redirect, ** pointing at this program in the CGI bin directory. ** 3. Add an entry to the file ".redirects" in the directory where your ** http server runs CGI programs. For most servers, this is the ** directory where the given CGI program lives. The format of the ** file is a bunch of lines with a filename, whitespace, and the new ** URL. For example: /test/oldfile.html http://www.acme.com/test/newfile.html ** The easiest way to figure out precisely what filename to put into ** .redirects is to set up the symlink and then click on it. You'll get ** back a "404 Not Found" page which includes the filename as received by ** the redirect program, and that's what you want to use. ** ** Note: this is designed for thttpd (http://www.acme.com/software/thttpd/) ** and using it with other web servers may require some hacking. A possible ** gotcha is with the symbolic link from the old file pointing at this ** script - servers other than thttpd may not allow that link to be run ** as a CGI program, because they don't check the link to see that it ** points into the allowed CGI directory. ** ** Note two: It would be really cool to have this program look for ** the .redirects file in the same directory as the file being redirected, ** instead of in the binaries directory. Unfortunately, this appears ** to be impossible with the information CGI gives, plus the non-standardized ** but widespread practice of running CGI programs in the directory where ** the binary lives. Perhaps CGI 1.2 will address this. */ #include #include #include #include #include "config.h" static char* argv0; static void internal_error( char* reason ) { char* title = "500 Internal Error"; (void) printf( "\ Status: %s\n\ Content-type: text/html\n\ \n\ %s\n\

%s

\n\ Something unusual went wrong during a redirection request:\n\

\n\ %s\n\

\n\ \n", title, title, title, reason ); } static void not_found( char* script_name ) { char* title = "404 Not Found"; (void) printf( "\ Status: %s\n\ Content-type: text/html\n\ \n\ %s\n\

%s

\n\ The requested filename, %s, is set up to be redirected to another URL;\n\ however, the new URL has not yet been specified.\n\ \n", title, title, title, script_name ); } static void moved( char* script_name, char* url ) { char* title = "Moved"; (void) printf( "\ Location: %s\n\ Content-type: text/html\n\ \n\ %s\n\

%s

\n\ The requested filename, %s, has moved to a new URL:\n\ %s.\n\ \n", url, title, title, script_name, url, url ); } int main( int argc, char** argv ) { char* script_name; char* path_info; char* cp; FILE* fp; char *star; char buf[5000], file[5000], url[5000]; argv0 = argv[0]; /* Get the name that we were run as, which is the filename being ** redirected. */ script_name = getenv( "SCRIPT_NAME" ); if ( script_name == (char*) 0 ) { internal_error( "Couldn't get SCRIPT_NAME environment variable." ); exit( 1 ); } /* Append the PATH_INFO, if any. This allows redirection of whole ** directories. */ path_info = getenv( "PATH_INFO" ); if ( path_info != (char*) 0 ) { cp = (char*) malloc( strlen( script_name ) + strlen( path_info ) + 1 ); if ( cp == (char*) 0 ) { internal_error( "Out of memory." ); exit( 1 ); } (void) sprintf( cp, "%s%s", script_name, path_info ); script_name = cp; } /* Open the redirects file. */ fp = fopen( ".redirects", "r" ); if ( fp == (FILE*) 0 ) { internal_error( "Couldn't open .redirects file." ); exit( 1 ); } /* Search the file for a matching entry. */ while ( fgets( buf, sizeof(buf), fp ) != (char*) 0 ) { /* Remove comments. */ cp = strchr( buf, '#' ); if ( cp != (char*) 0 ) *cp = '\0'; /* Skip leading whitespace. */ cp = buf; cp += strspn( cp, " \t" ); /* Check for blank line. */ if ( *cp != '\0' ) { /* Parse line. */ if ( sscanf( cp, "%[^ \t\n] %[^ \t\n]", file, url ) == 2 ) { /* Check for wildcard match. */ star = strchr( file, '*' ); if ( star != (char*) 0 ) { /* Check for leading match. */ if ( strncmp( file, script_name, star - file ) == 0 ) { /* Got it; put together the full name. */ strcat( url, script_name + ( star - file ) ); /* XXX Whack the script_name, too? */ moved( script_name, url ); exit( 0 ); } } /* Check for exact match. */ if ( strcmp( file, script_name ) == 0 ) { /* Got it. */ moved( script_name, url ); exit( 0 ); } } } } /* No match found. */ not_found( script_name ); exit( 1 ); }