From f51467cd80cc5b15b7b55da682547ffc15ac09f4 Mon Sep 17 00:00:00 2001
From: Alexander Popov <iiiypuk@fastmail.fm>
Date: Mon, 24 Mar 2025 23:56:25 +0300
Subject: [PATCH] =?UTF-8?q?=D0=9D=D0=B0=D0=B1=D1=80=D0=BE=D1=81=D0=BE?=
 =?UTF-8?q?=D0=BA=20=D0=BF=D1=80=D0=B8=D0=BC=D0=B5=D1=80=D0=B0=20=D1=80?=
 =?UTF-8?q?=D0=B0=D0=B1=D0=BE=D1=82=D1=8B=20=D1=81=20FIFO?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 code/C/FIFO/.gitignore |  4 +++
 code/C/FIFO/README.md  |  9 ++++++
 code/C/FIFO/reader.c   | 67 ++++++++++++++++++++++++++++++++++++++++++
 code/C/FIFO/writer.c   | 18 ++++++++++++
 4 files changed, 98 insertions(+)
 create mode 100644 code/C/FIFO/.gitignore
 create mode 100644 code/C/FIFO/README.md
 create mode 100644 code/C/FIFO/reader.c
 create mode 100644 code/C/FIFO/writer.c

diff --git a/code/C/FIFO/.gitignore b/code/C/FIFO/.gitignore
new file mode 100644
index 0000000..f0fd549
--- /dev/null
+++ b/code/C/FIFO/.gitignore
@@ -0,0 +1,4 @@
+example_fifo
+
+reader
+writer
diff --git a/code/C/FIFO/README.md b/code/C/FIFO/README.md
new file mode 100644
index 0000000..45b9392
--- /dev/null
+++ b/code/C/FIFO/README.md
@@ -0,0 +1,9 @@
+```sh
+clear; clang -std=c99 -o reader reader.c && ./reader
+# или
+tcc -run reader.c
+```
+
+```sh
+tcc -run writer.c
+```
diff --git a/code/C/FIFO/reader.c b/code/C/FIFO/reader.c
new file mode 100644
index 0000000..b447bc7
--- /dev/null
+++ b/code/C/FIFO/reader.c
@@ -0,0 +1,67 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/select.h>
+#include <poll.h>
+
+#define FIFO_NAME "example_fifo"
+
+int main() {
+  unsigned int timeout_seconds = 2;
+
+  while (true) {
+    int fd = open(FIFO_NAME, O_RDONLY | O_NONBLOCK);
+    if (fd < 0) {
+      perror("open");
+      return EXIT_FAILURE;
+    }
+
+    struct pollfd waiter = {.fd = fd, .events = POLLIN};
+
+    while (true) {
+      bool stop = false;
+
+      int poll_result = poll(&waiter, 1, timeout_seconds * 1000);
+      switch (poll_result) {
+      case 0:
+        puts("No data from fifo");
+        break;
+
+      case 1:
+        if (waiter.revents & POLLIN) {
+          char buffer[BUFSIZ];
+          ssize_t len = read(fd, buffer, sizeof(buffer));
+          if (len < 0) {
+            perror("read");
+            return EXIT_FAILURE;
+          }
+
+          printf("Data: %s\n", buffer);
+        } else if (waiter.revents & POLLERR) {
+          puts("Got a POLLERR");
+          return EXIT_FAILURE;
+        } else if (waiter.revents & POLLHUP) {
+          stop=true; // Writer closed its end
+          break;
+        }
+        break;
+
+      default:
+        perror("poll error");
+        return EXIT_FAILURE;
+      }
+
+      if (stop) {break;}
+    }
+
+    if (close(fd) < 0) {
+      perror("close");
+      return EXIT_FAILURE;
+    }
+  }
+
+  return EXIT_SUCCESS;
+}
diff --git a/code/C/FIFO/writer.c b/code/C/FIFO/writer.c
new file mode 100644
index 0000000..8d7c29f
--- /dev/null
+++ b/code/C/FIFO/writer.c
@@ -0,0 +1,18 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define FIFO_NAME "example_fifo"
+
+int main() {
+  char message[1024] = "OLOLO MESSAGE";
+
+  mkfifo(FIFO_NAME, 0666);
+  int fd = open(FIFO_NAME, O_WRONLY);
+  write(fd, message, sizeof(message));
+  close(fd);
+  // unlink(FIFO_NAME);
+
+  return 0;
+}