From eccb0e2701a7dd9d71ac68c98cebab3678b8c096 Mon Sep 17 00:00:00 2001
From: prnmxfqg4 <zimujunxue@163.com>
Date: Mon, 4 Jul 2022 21:03:55 +0800
Subject: [PATCH] ADD file via upload

---
 mycat.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 mycat.c

diff --git a/mycat.c b/mycat.c
new file mode 100644
index 0000000..6a78e9d
--- /dev/null
+++ b/mycat.c
@@ -0,0 +1,55 @@
+#define __LIBRARY__
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdarg.h>
+FILE __stdout;
+#define O_RDONLY	   00
+#define MSG_LEN 256
+#define MAX_NUMBER_BYTES 1024
+_syscall3(int,open,const char *,filename,int, flag,int, mode)
+_syscall3(int,write,int ,fd,const char *, buf, off_t ,count)
+_syscall3(int,read,int ,fildes,char *, buf, off_t ,count)
+_syscall0(int,sync)
+_syscall1(int,close,int,fildes)
+_syscall3(int ,vsprintf1,char *, buf, const char *, fmt, va_list ,args)
+
+static char printbuf[1024];
+int printf(const char *fmt,...)
+{
+	write(2,fmt,strlen(fmt));
+}
+int main(int argc, char **argv)
+{
+  int num, fd;
+  char msg[MSG_LEN+1];
+
+  if (argc == 1)
+    return EXIT_FAILURE;
+
+  /* open the file */
+  if ((fd=open(argv[1], O_RDONLY, 0)) < 0)
+    return EXIT_FAILURE;
+  do{
+    /* read the file */
+    if ((num = read(fd, msg, MSG_LEN)) < 0) {
+      close(fd);
+      return EXIT_FAILURE;
+    } else if (num == 0) {
+      break;
+    }
+    /* display on screen */
+    msg[num] = '\0';
+    printf( msg);
+  }while(1);
+  printf("\n");
+
+  /* exit */
+  close(fd);
+  sync();
+
+  return EXIT_SUCCESS;
+}