/* wwwcli.c */
/* This source is to be compiled by UNIX gcc. */
/*	wwwcli URL    : Directly from server
	wwwcli URL -h : Don't output header
	wwwcli URL -c : "Content-Type:" header
        wwwcli URL -H : "HEAD" method
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <fcntl.h>
#define WWW_PORT 80
#define PROG_DNS "nslookup"
/* "/export/home1/johnkoji/bin/dns" */
/* "/usr/sbin/nslookup" */
#define HEADER_TYPE "Content-Type:"

void Err_Exit( char *x )
{
	fputs("client- ", stderr ) ;
	perror( x ) ;
	exit(1) ;
}
void Err( char *x )
{
	fputs("client- ", stderr ) ;
	perror( x ) ;
}
/* From "130.54.54.194" IP address string, set 4-byte sin_addr */
int set_ip_addr( u_char *sin_addr, char *ip_text )
{
	u_int i, n_ip[4] ;

	if( sscanf( ip_text,"%u.%u.%u.%u", n_ip, n_ip+1, n_ip+2, n_ip+3 )!= 4 )
		return -1 ;
	for( i=0 ; i<4 ; i++ )
		sin_addr[i] = n_ip[i] & 0xff ;
	return 0 ;  /* OK */
}
/* From "www.kyoto-u.ac.jp" domain name address string, get IP address
	by 'nslookup' command and set 4-byte sin_addr */
int nslookup( u_char *sin_addr, char *dn_text )
{
	u_int i, n_ip[4] ;
	char line_buf[128] ;
	FILE *fp ;

#ifdef DNS_TMP_FILE
        char tmp_fn[24] ;

	sprintf( tmp_fn,"/tmp/nslookup%04x.tmp", getpid() ) ;
	sprintf( line_buf,"%s \"%s.\" > %s", PROG_DNS, dn_text, tmp_fn ) ;
        if( system( line_buf )!= 0 )
		return -1 ;
	if( (fp = fopen( tmp_fn,"rt"))== NULL )
		return -2 ;
#else
        sprintf( line_buf,"%s \"%s.\"", PROG_DNS, dn_text ) ;

        if( (fp = popen( line_buf,"r"))== NULL )
                return -1 ;
#endif
	while( fgets( line_buf, 128, fp )!= NULL )
	{	if( strncmp( line_buf,"Name:", 5 )== 0 &&
		  fgets( line_buf, 128, fp )!= NULL &&
		  ( strncmp( line_buf,"Address:", 8 )== 0 || strncmp( line_buf,"Addresses:", 10 )== 0 )&&
		  sscanf(line_buf,"%*s %u.%u.%u.%u",n_ip,n_ip+1,n_ip+2,n_ip+3)==4 )
		{	for( i=0 ; i<4 ; i++ )
				sin_addr[i] = n_ip[i] & 0xff ;
#ifdef DNS_TMP_FILE
			fclose( fp ) ;
			remove( tmp_fn ) ;
#else
                        pclose( fp ) ;
#endif
			return 0 ;  /* OK */
		}
	}
#ifdef DNS_TMP_FILE
	fclose( fp ) ;
	remove( tmp_fn ) ;
#else
        pclose( fp ) ;
#endif
	return -3 ;
}
FILE *open_http( char *url, char *mode, struct sockaddr_in *remote_s )
{
	int i, socket_id, serv_port=WWW_PORT ;
#if defined(GETHOSTBYNAME)
	struct hostent *shost ;
#endif
	char hostname[128], send_message[1024] ;
	char *filename, *file_mode ;
	u_char *cp ;
	FILE *fp ;

/* Get hostname/filename/port No. from URL */
	if( strncmp( url,"http://",7 )== 0 )
		cp = url+7 ;
	else
		cp = url ;
	i = strcspn( cp,"/" ) ;
	strncpy( hostname, cp, i ) ;
	if( (filename = strchr( cp,'/'))==NULL )
	{	fprintf( stderr,"URL Error:\n%s\n", url ) ;
		return NULL ;
	}
	hostname[i] ='\0' ;
	if( (cp = strrchr( hostname,':'))!= NULL && sscanf( cp+1,"%u", &i )==1 )
	{	serv_port = i ;
		*cp = '\0' ;
	}
/* Create a socket */
	if( (socket_id = socket(PF_INET, SOCK_STREAM, 0)) <0 )
	{	Err("socket");
		return NULL ;
	}
	bzero( (char *)remote_s, sizeof( struct sockaddr_in ) ) ;
	remote_s->sin_family = PF_INET ;
	remote_s->sin_port = htons( serv_port ) ;
/* Set IP address */
	cp = (char *)&(remote_s->sin_addr) ;
	if( set_ip_addr( cp, hostname )!= 0 && nslookup( cp, hostname )!= 0 )
	{	fprintf( stderr,"Unknown host: %s\n", hostname ) ;
		return NULL ;
	}
	if( connect( socket_id, remote_s, sizeof( struct sockaddr_in ) ) != 0 )
	{	Err("connect") ;
		return NULL ;
	}
/* HTTP command */
        if( (file_mode = strdup( mode ))== NULL ){
            Err("strdup") ;
            return NULL ;
        }
        if( (cp = strchr( file_mode,'H'))!= NULL ){
            sprintf( send_message,"HEAD %s HTTP/1.0\nUser-Agent: WWW Client(UNIX)\n\n", filename ) ;
            *cp = '\0' ;
        }else{
	    sprintf( send_message,"GET %s HTTP/1.0\nUser-Agent: WWW Client(UNIX)\n\n", filename ) ;
        }
	send( socket_id, send_message, strlen(send_message), 0 );
	if( (fp = fdopen( socket_id, file_mode ))== NULL )
	{	Err("fdopen") ;
                free( file_mode ) ;
		return NULL;
	}
        free( file_mode ) ;
	return fp ;
}
#define C_BUF_SIZE 512
int main( int argc, char **argv )
{
	char c_buf[C_BUF_SIZE] ;
	char *url, *file_mode = "rb" ;
	int i, mode = 255 ;
	FILE *fp ;
	struct sockaddr_in socket_name ;

	if( argc == 1 )
	{	fprintf( stderr,"Usage: \"%s URL\"\n", argv[0] ) ;
		exit(1) ;
	}
	url = argv[1] ;
	if( url[0] == '/')   /* PATH_INFO */
		url ++ ;
	if( argc > 2 )
	{	if( strchr( argv[2],'c')!= NULL ){ /* "Content-Type:" only */
			mode = 1 ;
		}else if( strchr( argv[2],'h')!= NULL ){ /* No header */
			mode = 0 ;
                }else if( strchr( argv[2],'H')!= NULL ){ /* "HEAD" method */
                        mode = 255 ;
                        file_mode = "rbH" ;
		}else{
			mode = 255 ;
                }
	}
	if( (fp = open_http( url, file_mode, &socket_name ))== NULL )
		exit(1) ;
	while( fgets( c_buf, C_BUF_SIZE, fp )!= NULL && strlen( c_buf ) > 2 )
	{	if( mode == 1 && strncmp( c_buf,HEADER_TYPE,strlen(HEADER_TYPE) )== 0 )
			fputs( c_buf, stdout ) ;   /* Output "Content-Type:" */
		else if( mode == 255 )
			fputs( c_buf, stdout ) ;
	}
	if( mode != 0 )   /* Output "\n" */
		fputs( c_buf, stdout ) ;
	while( (i = fread( c_buf, 1, C_BUF_SIZE, fp )) > 0 )
		fwrite( c_buf, 1, i, stdout ) ;
	fclose( fp ) ;
	return 0 ;
}