/* Program name : server.c
*Ajay Shankar Bidyarthy, Email: b.ajay@iitg.ernet.in
*/
#include /* printf(3) et al. */
#include /* getopt(3), read(2), etc. */
#include /* exit(2). */
#include /* errno declaration & error codes. */
#include /* String manipulation & memory functions. */
#include /* time(2) & ctime(3). */
#include
#include /* Socket functions (socket(2), bind(2), etc). */
#include /* sockaddr_in & sockaddr_in6 definition. */
#include
#include
/*
* This function reports the error and exits back to the shell:
*/
static void bail(const char *on_what)
{
fputs(strerror(errno),stderr);
fputs(": ",stderr);
fputs(on_what,stderr);
fputc('\n',stderr);
exit(1);
}
int main(int argc,char **argv)
{
int z,i;
char *srvr_addr = NULL;
struct sockaddr_in adr_inet;/* AF_INET */
struct sockaddr_in adr_clnt;/* AF_INET */
int len_inet; /* length */
int s; /* Socket */
char dgram[512]; /* Recv buffer */
struct stat sb;
/*
* Use a server address from the command line, if one has been provided. Otherwise, this program will default to using the arbitrary address
* 127.0.0.23:
*/
if ( argc >= 2 )
{
/* Addr on cmdline: */
srvr_addr = argv[1];
}
else
{
/* Use default address: */
srvr_addr = "127.0.0.23";
}
/*
* Create a UDP socket to use:
*/
s = socket(AF_INET,SOCK_DGRAM,0);
if ( s == -1 )
bail("socket()");
/*
* Create a socket address, for use with bind(2):
*/
memset(&adr_inet,0,sizeof adr_inet);
adr_inet.sin_family = AF_INET;
adr_inet.sin_port = htons(9099);
adr_inet.sin_addr.s_addr =
inet_addr(srvr_addr);
if ( adr_inet.sin_addr.s_addr == INADDR_NONE )
bail("bad address."); /* prints error if no such ip address exist in the network*/
len_inet = sizeof adr_inet;
/*
* Bind a address to our socket, so that client programs can contact this server:
*/
z = bind(s, (struct sockaddr *)&adr_inet, len_inet);
if ( z == -1 )
bail("bind()");
/*
* Now wait for requests:
*/
for (;;)
{
/*
* Block until the program receives a datagram at our address and port:
*/socklen_t t;
t=sizeof adr_clnt;
//fprintf(stderr,"flag1");
len_inet = sizeof adr_clnt;
z = recvfrom(s, /* Socket */
dgram, /* Receiving buffer */
512, /* Max recv buf size */
0, /* Flags: no options */
(struct sockaddr *)&adr_clnt, /* Addr */
&t); /* Addr len, in & out */
// if ( z < 0 )
// bail("recvfrom(2)");
fprintf(stderr,"%d",strlen(dgram));
char a[strlen(dgram)-4];
for(i=strlen(dgram)-4;i>=0;i--)
a[i]=dgram[i];
fprintf(stderr,"%s",a);
/* New */
fprintf(stderr,"\n Hello \n");
fprintf(stderr,"Client from %s port %u;\n",
inet_ntoa(adr_clnt.sin_addr),
(unsigned)ntohs(adr_clnt.sin_port));
/* end new */
fprintf(stderr,"%s",dgram);
stat(a,&sb);
/*
* Process the request:
*/
// dgram[z] = 0; /* null terminate */
// if ( !strcasecmp(dgram,"QUIT") )
// break; /* Quit server */
/*
* Get the current date and time:
*/
// time(&td); /* Get current time & date */
// tm = *localtime(&td); /* Get components */
/*
* Format a new date and time string, based upon the input format string:
*/
// strftime(dtfmt, /* Formatted result */
// sizeof dtfmt, /* Max result size */
// dgram, /* Input date/time format */
// &tm); /* Input date/time values */
/*
* Send the formatted result back to the client program:
*/
printf("%s",ctime(&sb.st_mtime));
z = sendto(s, /* Socket to send result */
ctime(&sb.st_mtime), /* The datagram result to snd */
strlen(ctime(&sb.st_mtime)), /* The datagram lngth */
0, /* Flags: no options */
(struct sockaddr *)&adr_clnt,/* addr */
len_inet); /* Client address length */
if ( z < 0 )
bail("sendto(2)");
}
/*
* Close the socket and exit:
*/
close(s);
return 0;
}
*Ajay Shankar Bidyarthy, Email: b.ajay@iitg.ernet.in
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
/*
* This function reports the error and exits back to the shell:
*/
{
fputs(strerror(errno),stderr);
fputs(": ",stderr);
fputs(on_what,stderr);
fputc('\n',stderr);
exit(1);
}
int main(int argc,char **argv)
{
int z,i;
char *srvr_addr = NULL;
struct sockaddr_in adr_inet;/* AF_INET */
struct sockaddr_in adr_clnt;/* AF_INET */
int len_inet; /* length */
int s; /* Socket */
char dgram[512]; /* Recv buffer */
struct stat sb;
/*
* Use a server address from the command line, if one has been provided. Otherwise, this program will default to using the arbitrary address
* 127.0.0.23:
*/
if ( argc >= 2 )
{
/* Addr on cmdline: */
srvr_addr = argv[1];
}
else
{
/* Use default address: */
srvr_addr = "127.0.0.23";
}
/*
* Create a UDP socket to use:
*/
s = socket(AF_INET,SOCK_DGRAM,0);
if ( s == -1 )
bail("socket()");
/*
* Create a socket address, for use with bind(2):
*/
memset(&adr_inet,0,sizeof adr_inet);
adr_inet.sin_family = AF_INET;
adr_inet.sin_port = htons(9099);
adr_inet.sin_addr.s_addr =
inet_addr(srvr_addr);
if ( adr_inet.sin_addr.s_addr == INADDR_NONE )
bail("bad address."); /* prints error if no such ip address exist in the network*/
len_inet = sizeof adr_inet;
/*
* Bind a address to our socket, so that client programs can contact this server:
*/
z = bind(s, (struct sockaddr *)&adr_inet, len_inet);
if ( z == -1 )
bail("bind()");
/*
* Now wait for requests:
*/
for (;;)
{
/*
* Block until the program receives a datagram at our address and port:
*/socklen_t t;
t=sizeof adr_clnt;
//fprintf(stderr,"flag1");
len_inet = sizeof adr_clnt;
z = recvfrom(s, /* Socket */
dgram, /* Receiving buffer */
512, /* Max recv buf size */
0, /* Flags: no options */
(struct sockaddr *)&adr_clnt, /* Addr */
&t); /* Addr len, in & out */
// if ( z < 0 )
// bail("recvfrom(2)");
fprintf(stderr,"%d",strlen(dgram));
char a[strlen(dgram)-4];
for(i=strlen(dgram)-4;i>=0;i--)
a[i]=dgram[i];
fprintf(stderr,"%s",a);
/* New */
fprintf(stderr,"\n Hello \n");
fprintf(stderr,"Client from %s port %u;\n",
inet_ntoa(adr_clnt.sin_addr),
(unsigned)ntohs(adr_clnt.sin_port));
/* end new */
fprintf(stderr,"%s",dgram);
stat(a,&sb);
/*
* Process the request:
*/
// dgram[z] = 0; /* null terminate */
// if ( !strcasecmp(dgram,"QUIT") )
// break; /* Quit server */
/*
* Get the current date and time:
*/
// time(&td); /* Get current time & date */
// tm = *localtime(&td); /* Get components */
/*
* Format a new date and time string, based upon the input format string:
*/
// strftime(dtfmt, /* Formatted result */
// sizeof dtfmt, /* Max result size */
// dgram, /* Input date/time format */
// &tm); /* Input date/time values */
/*
* Send the formatted result back to the client program:
*/
printf("%s",ctime(&sb.st_mtime));
z = sendto(s, /* Socket to send result */
ctime(&sb.st_mtime), /* The datagram result to snd */
strlen(ctime(&sb.st_mtime)), /* The datagram lngth */
0, /* Flags: no options */
(struct sockaddr *)&adr_clnt,/* addr */
len_inet); /* Client address length */
if ( z < 0 )
bail("sendto(2)");
}
/*
* Close the socket and exit:
*/
close(s);
return 0;
}
