no relation process using FIFO

UNP/IPC/FIFO/fifo.h

@@ -0,0 +1,56 @@
+#define FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
+#define FIFO1 "/tmp/fifo.1"
+#define FIFO2 "/tmp/fifo.2"
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <wait.h>
+
+// 服务器向客户返回文件内容
+void client(int readfd, int writefd)
+{
+    size_t len;
+    ssize_t n;
+    char buf[128];
+    fgets(buf, 128, stdin);
+    len = strlen(buf);
+    // fgets 会在结尾自动加上'\n'字符
+    if (buf[len - 1] == '\n')
+        len--;
+    write(writefd, buf, len);
+    while ((n = read(readfd, buf, 128)) > 0)
+    {
+        write(STDOUT_FILENO, buf, n);
+    }
+}
+
+void server(int readfd, int writefd)
+{
+    int fd;
+    ssize_t n;
+    char buf[128 + 1];
+    if ((n = read(readfd, buf, 128)) == 0)
+    {
+        fprintf(stderr, "Error path name\n");
+        exit(1);
+    }
+    buf[n] = '\0';
+    if ((fd = open(buf, O_RDONLY)) < 0)
+    {
+        snprintf(buf + n, sizeof(buf) - n, ": can't open, %s\n", strerror(errno));
+        n = strlen(buf);
+        write(writefd, buf, n);
+    }
+    else
+    {
+        while ((n = read(fd, buf, 128)) > 0)
+        {
+            write(writefd, buf, n);
+        }
+        close(fd);
+    }
+}