void
client(int readid, int writeid)
{
size_t len;
ssize_t n;
char *ptr;
struct mymesg mesg;
/* start buffer with msqid and a blank */
snprintf(mesg.mesg_data, MAXMESGDATA, "%d ", readid);
len = strlen(mesg.mesg_data);
ptr = mesg.mesg_data + len;
/* read pathname */
Fgets(ptr, MAXMESGDATA - len, stdin);
len = strlen(mesg.mesg_data);
if (mesg.mesg_data[len-1] == '\n')
len--; /* delete newline from fgets() */
mesg.mesg_len = len;
mesg.mesg_type = 1;
/* write msqid and pathname to server's well-known queue */
Mesg_send(writeid, &mesg);
/* read from our queue, write to standard output */
while ( (n = Mesg_recv(readid, &mesg)) > 0)
Write(STDOUT_FILENO, mesg.mesg_data, n);
}
void
server(int readfd, int writefd)
{
FILE *fp;
ssize_t n;
struct mymesg mesg;
/* 4read pathname from IPC channel */
mesg.mesg_type = 1;
if ( (n = Mesg_recv(readfd, &mesg)) == 0)
err_quit("pathname missing");
mesg.mesg_data[n] = '\0'; /* null terminate pathname */
if ( (fp = fopen(mesg.mesg_data, "r")) == NULL) {
/* 4error: must tell client */
snprintf(mesg.mesg_data + n, sizeof(mesg.mesg_data) - n,
": can't open, %s\n", strerror(errno));
mesg.mesg_len = strlen(mesg.mesg_data);
Mesg_send(writefd, &mesg);
} else {
/* 4fopen succeeded: copy file to IPC channel */
while (Fgets(mesg.mesg_data, MAXMESGDATA, fp) != NULL) {
mesg.mesg_len = strlen(mesg.mesg_data);
Mesg_send(writefd, &mesg);
}
Fclose(fp);
}
/* 4send a 0-length message to signify the end */
mesg.mesg_len = 0;
Mesg_send(writefd, &mesg);
}
void
server(int readfd, int writefd)
{
FILE *fp;
char *ptr;
pid_t pid;
ssize_t n;
struct mymesg mesg;
// iterate server
for ( ; ; ) {
/* read pathname from IPC channel */
mesg.mesg_type = 1; // need type 1 (client request)
if ( (n = Mesg_recv(readfd, &mesg)) == 0) {
err_msg("pathname missing");
continue;
}
mesg.mesg_data[n] = '\0'; /* null terminate pathname */
if ( (ptr = strchr(mesg.mesg_data, ' ')) == NULL) {
err_msg("bogus request: %s", mesg.mesg_data);
continue;
}
*ptr++ = 0; /* null terminate PID, ptr = pathname */
pid = atol(mesg.mesg_data);
mesg.mesg_type = pid; /* for messages back to client */
if ( (fp = fopen(ptr, "r")) == NULL) {
/* error: must tell client */
snprintf(mesg.mesg_data + n, sizeof(mesg.mesg_data) - n,
": can't open, %s\n", strerror(errno));
mesg.mesg_len = strlen(ptr);
//
memmove(mesg.mesg_data, ptr, mesg.mesg_len);
Mesg_send(writefd, &mesg);
} else {
/* fopen succeeded: copy file to IPC channel */
while (Fgets(mesg.mesg_data, MAXMESGDATA, fp) != NULL) {
// every line is a msg
mesg.mesg_len = strlen(mesg.mesg_data);
Mesg_send(writefd, &mesg);
}
Fclose(fp);
}
/* send a 0-length message to signify the end */
mesg.mesg_len = 0;
Mesg_send(writefd, &mesg);
}
}
void
client(int readfd, int writefd)
{
size_t len;
ssize_t n;
struct mymesg mesg;
/* 4read pathname */
Fgets(mesg.mesg_data, MAXMESGDATA, stdin);
len = strlen(mesg.mesg_data);
if (mesg.mesg_data[len-1] == '\n')
len--; /* delete newline from fgets() */
mesg.mesg_len = len;
mesg.mesg_type = 1;
/* 4write pathname to IPC channel */
Mesg_send(writefd, &mesg);
/* 4read from IPC, write to standard output */
while ( (n = Mesg_recv(readfd, &mesg)) > 0)
Write(STDOUT_FILENO, mesg.mesg_data, n);
}
