Add reader writer process demo

.gitignore

@@ -2,12 +2,16 @@
 *.out
 *.bin
 *.exe
+*.txt
 ashwathama
 bash_gitignore.sh
 endian
 garibsh
 ior
 myps
 pid
+reader
+run_writer_readers.sh
 sync
 threads
+writer

ext_ignore.txt

@@ -2,3 +2,4 @@
 *.out
 *.bin
 *.exe
+*.txt

reader.c

@@ -0,0 +1,40 @@
+#include<stdio.h>
+#include<stdlib.h>
+#include<sys/types.h>
+#include<sys/uio.h>
+#include<fcntl.h>
+#include<unistd.h>
+
+int main(void) {
+
+  int fd;
+  int bytes_read;
+  char buf[51200];
+  fd = open("./delme.txt", O_RDONLY);
+
+  printf("fd = %d\n", fd);
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  printf("________\n");
+
+  // 1 sec = 1000000
+  //usleep(500000);
+  sleep(5);
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  printf("________\n");
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  printf("________\n");
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+  printf("________\n");
+  bytes_read = read(fd, buf, sizeof(buf));
+  printf("%d bytes read: %s\n", bytes_read, buf);
+}

writer.c

@@ -0,0 +1,36 @@
+#include<stdio.h>
+#include<fcntl.h>
+#include<unistd.h>
+#include<sys/types.h>
+#include<sys/stat.h>
+
+int main(void) {
+  int fd, i;
+  int bytes_written;
+  char buf[51200];
+  for (i = 0; i < sizeof(buf); i++) {
+    buf[i] = 'a';
+  }
+  fd = open("./delme.txt", O_WRONLY | O_CREAT, 0777);
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  printf("_______\n");
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  printf("_______\n");
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  printf("_______\n");
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  printf("_______\n");
+  bytes_written = write(fd, buf, sizeof(buf));
+  printf("%d bytes written\n", bytes_written);
+  close(fd);
+}