IPC using pipes

Pipes/2ProcessPipes.c

@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+int main(int argc, char* argv[]) {
+
+	int pfds[2];
+	char buf[30];
+
+	pipe(pfds);
+
+
+	/*
+		fork() : 
+			-> Generate the clone of the calling process.
+			-> Calling process is parent process and new
+				process is child process.
+			-> Return value :
+				1. value 0 : means the current process is child process
+							which is newly forked and forking is successful.
+				2. value -1 : means the forking the process has failed.
+								The value is retured to parent process.
+				3. value <Some integer value> : means the current process is 
+								parent process and it is the process id of 
+								the newly forked child process on the system.
+	*/
+	if (!fork()) {
+
+		printf(" CHILD : writing to the pipe\n");
+		write(pfds[1], "test", 5);
+		printf(" CHILD: exiting\n");
+		exit(0);
+	}
+	else {
+		printf("PARENT: reading from pipe\n");
+		read(pfds[0], buf, 5);
+		printf("PARENT: read \"%s\"\n", buf);
+		wait(NULL);
+	}
+
+	/*
+		The parent process should wait for forked child
+		process to finish the execution and notify the parent.
+		Otherwise, the parent would also terminating without 
+		knowing the process execution info about the child
+		process and the child process would keep running turning
+		itself to a zombie process.
+		Here, we use wait() sys call for parent to wait for 
+		child process.
+	*/
+	return 0;
+}

Pipes/CMakeLists.txt

@@ -0,0 +1,24 @@
+# CMakeList.txt : CMake project for Pipes, include source and define
+# project specific logic here.
+#
+cmake_minimum_required (VERSION 3.8)
+
+# Enable Hot Reload for MSVC compilers if supported.
+if (POLICY CMP0141)
+  cmake_policy(SET CMP0141 NEW)
+  set(CMAKE_MSVC_DEBUG_INFORMATION_FORMAT "$<IF:$<AND:$<C_COMPILER_ID:MSVC>,$<CXX_COMPILER_ID:MSVC>>,$<$<CONFIG:Debug,RelWithDebInfo>:EditAndContinue>,$<$<CONFIG:Debug,RelWithDebInfo>:ProgramDatabase>>")
+endif()
+
+project(Pipes VERSION 1.0.0 LANGUAGES C CXX)
+
+set(CMAKE_CXX_STANDARD          17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS        OFF)
+
+# Add source to this project's executable.
+add_executable (Pipes_demo "Pipes_demo.c" )
+add_executable (2ProcessPipes "2ProcessPipes.c")
+
+
+
+# TODO: Add tests and install targets if needed.

Pipes/Pipes_demo.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <unistd.h>
+
+int main(int argc, char* argv[]) {
+	
+	int pfds[2];
+	char buf[30];
+
+	if (pipe(pfds) == -1) {
+		perror("pipes");
+		exit(1);
+	}
+
+	printf("writing to file descriptor #%d\n", pfds[1]);
+	write(pfds[1], "test", 5);
+	printf("reading from file descriptor #%d\n", pfds[0]);
+	read(pfds[0], buf, 5);
+	printf("read \"%s\"\n", buf);
+
+	return 0;
+}