/** If buffer is too small to hold entire string, it is incremented by this value */
#define BUFFER_STEP 16
+/** Buffer used to store line of characters */
+char * buffer = NULL;
+
+/** Named pipe used to communnicate with process2 */
+char * write_pipe = "/tmp/process1pipe";
+
+/** File descriptor of pipe */
+int file_descriptor;
+
/**
* Handler for signals.
*/
void sig_handler(int signo)
{
if (signo == SIGUSR1) {
- fprintf(stderr, "[%s] SIGUSR1!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGUSR1!\n", "process1");
}
- else if (signo == SIGUSR2) {
- fprintf(stderr, "[%s] SIGUSR2!\n", "process1");
+ else if (signo == SIGQUIT) {
+ fprintf(stderr, "[%s] Received SIGQUIT!\n", "process1");
+ fprintf(stderr, "[%s] > Releasing resources\n", "process1");
+ close(write_pipe);
+ unlink(write_pipe);
+
+ if (buffer) {
+ free(buffer);
+ buffer = NULL;
+ }
+ exit(0);
}
else if (signo == SIGINT) {
- fprintf(stderr, "[%s] SIGINT!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGINT!\n", "process1");
+ fprintf(stderr, "[%s] > Closing pipe\n", "process1");
+ close(write_pipe);
}
else if (signo == SIGCONT) {
- fprintf(stderr, "[%s] SIGCONT!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGCONT!\n", "process1");
+ fprintf(stderr, "[%s] > Opening pipe\n", "process1");
+ file_descriptor = open(write_pipe, O_WRONLY);
}
}
/** Currently fetched from stdin character */
int c;
- /** Buffer used to store line of characters */
- char * buffer = NULL;
-
/** Current buffer length*/
int buffer_length = 0;
*/
char * tmp = NULL;
- /** Named pipe used to communnicate with process2 */
- char * write_pipe = "/tmp/process1pipe";
-
- /** File descriptor of pipe */
- int file_descriptor;
-
fprintf(stderr, "[%s] Init!\n", "process1");
/**
if (signal(SIGUSR1, sig_handler) == SIG_ERR) {
fprintf(stderr, "can't catch SIGUSR1\n");
}
- if (signal(SIGUSR2, sig_handler) == SIG_ERR) {
- fprintf(stderr, "can't catch SIGUSR2\n");
+ if (signal(SIGQUIT, sig_handler) == SIG_ERR) {
+ fprintf(stderr, "can't catch SIGQUIT\n");
}
if (signal(SIGINT, sig_handler) == SIG_ERR) {
fprintf(stderr, "can't catch SIGINT\n");
}
} while(c != EOF);
+ /* Release resources in normal program flow exit. */
close(write_pipe);
unlink(write_pipe);
#include <stdio.h>
+/* exit.. */
+#include <stdlib.h>
/* open/read/write/close */
#include <fcntl.h>
/** If buffer is too small to hold entire string, it is incremented by this value */
#define BUFFER_STEP 16
+/** Named pipe used to communicate with process1 */
+char * read_pipe = "/tmp/process1pipe";
+
+/** Named pipe used to communicate with process3 */
+char * write_pipe = "/tmp/process2pipe";
+
+/** Descriptor of input pipe */
+int read_descriptor;
+
+/** Descriptor of output pipe */
+int write_descriptor;
+
/**
* Handler for signals.
*/
void sig_handler(int signo)
{
if (signo == SIGUSR1) {
- fprintf(stderr, "[%s] SIGUSR1!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGUSR1!\n", "process2");
}
- else if (signo == SIGUSR2) {
- fprintf(stderr, "[%s] SIGUSR2!\n", "process1");
+ else if (signo == SIGQUIT) {
+ fprintf(stderr, "[%s] Received SIGQUIT!\n", "process2");
+ fprintf(stderr, "[%s] > Releasing resources\n", "process2");
+ close(read_descriptor);
+ close(write_descriptor);
+ unlink(write_descriptor);
+ exit(0);
}
else if (signo == SIGINT) {
- fprintf(stderr, "[%s] SIGINT!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGINT!\n", "process2");
+ fprintf(stderr, "[%s] > Closing pipes\n", "process2");
+ close(read_descriptor);
+ close(write_descriptor);
}
else if (signo == SIGCONT) {
- fprintf(stderr, "[%s] SIGCONT!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGCONT!\n", "process2");
+ fprintf(stderr, "[%s] > Opening pipes\n", "process2");
+ read_descriptor = open(read_pipe, O_RDONLY);
+ write_descriptor = open(write_pipe, O_WRONLY);
}
}
* and pass the value to process3.
*/
int main(void) {
- /** Named pipe used to communicate with process1 */
- char * read_pipe = "/tmp/process1pipe";
-
- /** Named pipe used to communicate with process3 */
- char * write_pipe = "/tmp/process2pipe";
-
- /** Descriptor of input pipe */
- int read_descriptor;
-
- /** Descriptor of output pipe */
- int write_descriptor;
-
/**
* Buffer used for storing data from input pipe.
* Data is stored in chunks of BUFFER_STEP size.
/** Stores number of bytes read from input pipe in current iteration */
ssize_t count = 0;
- /* Reading from process1 */
- read_descriptor = open(read_pipe, O_RDONLY);
-
- /* Writing to process2 */
- mkfifo(write_pipe, 0666);
- write_descriptor = open(write_pipe, O_WRONLY);
-
int number_of_characters = 0;
fprintf(stderr, "[%s] Init!\n", "process2");
if (signal(SIGUSR1, sig_handler) == SIG_ERR) {
fprintf(stderr, "can't catch SIGUSR1\n");
}
- if (signal(SIGUSR2, sig_handler) == SIG_ERR) {
- fprintf(stderr, "can't catch SIGUSR2\n");
+ if (signal(SIGQUIT, sig_handler) == SIG_ERR) {
+ fprintf(stderr, "can't catch SIGQUIT\n");
}
if (signal(SIGINT, sig_handler) == SIG_ERR) {
fprintf(stderr, "can't catch SIGINT\n");
fprintf(stderr, "can't catch SIGCONT\n");
}
+ /* Reading from process1 */
+ read_descriptor = open(read_pipe, O_RDONLY);
+
+ /* Writing to process2 */
+ mkfifo(write_pipe, 0666);
+ write_descriptor = open(write_pipe, O_WRONLY);
+
while(1) {
/* Read data from input pipe */
count = read(read_descriptor, buffer, BUFFER_STEP);
}
}
+ /* Release resources in normal program flow exit. */
close(read_descriptor);
close(write_descriptor);
unlink(write_descriptor);
#include <stdio.h>
+/* exit.. */
+#include <stdlib.h>
+
/* open/read/write/close */
#include <fcntl.h>
/* Signals handling.. */
#include <signal.h>
+/** Named pipe used to communicate with process2 */
+char * read_pipe = "/tmp/process2pipe";
+
+/** Descriptor of input pipe */
+int read_descriptor;
+
/**
* Handler for signals.
*/
void sig_handler(int signo)
{
if (signo == SIGUSR1) {
- fprintf(stderr, "[%s] SIGUSR1!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGUSR1!\n", "process3");
}
- else if (signo == SIGUSR2) {
- fprintf(stderr, "[%s] SIGUSR2!\n", "process1");
+ else if (signo == SIGQUIT) {
+ fprintf(stderr, "[%s] Received SIGQUIT!\n", "process3");
+ fprintf(stderr, "[%s] > Releasing resources\n", "process3");
+ close(read_descriptor);
+ exit(0);
}
else if (signo == SIGINT) {
- fprintf(stderr, "[%s] SIGINT!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGINT!\n", "process3");
+ fprintf(stderr, "[%s] > Closing pipe\n", "process2");
+ close(read_descriptor);
}
else if (signo == SIGCONT) {
- fprintf(stderr, "[%s] SIGCONT!\n", "process1");
+ fprintf(stderr, "[%s] Received SIGCONT!\n", "process3");
+ fprintf(stderr, "[%s] > Opening pipe\n", "process2");
+ read_descriptor = open(read_pipe, O_RDONLY);
}
}
* grabbed data to the standard output.
*/
int main(void) {
- /** Named pipe used to communicate with process2 */
- char * read_pipe = "/tmp/process2pipe";
-
- /** Descriptor of input pipe */
- int read_descriptor;
-
/** Buffer used for storing data from input pipe */
int buffer = 0;
if (signal(SIGUSR1, sig_handler) == SIG_ERR) {
fprintf(stderr, "can't catch SIGUSR1\n");
}
- if (signal(SIGUSR2, sig_handler) == SIG_ERR) {
- fprintf(stderr, "can't catch SIGUSR2\n");
+ if (signal(SIGQUIT, sig_handler) == SIG_ERR) {
+ fprintf(stderr, "can't catch SIGQUIT\n");
}
if (signal(SIGINT, sig_handler) == SIG_ERR) {
fprintf(stderr, "can't catch SIGINT\n");
}
}
+ /* Release resources in normal program flow exit. */
close(read_descriptor);
return 0;