From f7eeb033da7df55ded207f5cda0e6257b2ae0167 Mon Sep 17 00:00:00 2001
From: prnmxfqg4 <zimujunxue@163.com>
Date: Mon, 4 Jul 2022 21:03:14 +0800
Subject: [PATCH] ADD file via upload

---
 mylib.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 mylib.c

diff --git a/mylib.c b/mylib.c
new file mode 100644
index 0000000..667fc31
--- /dev/null
+++ b/mylib.c
@@ -0,0 +1,65 @@
+#define __LIBRARY__
+#include <unistd.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define	EINVAL	4
+
+extern char ** environ;
+#define	__environ	environ
+
+char * ___strtok;
+volatile int errno;
+
+_syscall1(int,setup,void *,BIOS)
+
+volatile void exit(int exit_code)
+{
+	__asm__("int $0x80"::"a" (__NR_exit),"b" (exit_code));
+	while(1); /* to avoid warning of compiler */
+}
+
+extern char _end;
+void * ___brk_addr = &_end;
+
+int brk(void * end_data_segment)
+{
+	long __res;
+	__asm__ volatile ("int $0x80"
+		: "=a" (__res)
+		: "0" (__NR_brk),"b" ((long)(end_data_segment)));
+	if (__res >= 0) {
+		___brk_addr = end_data_segment;
+		return (int) __res;
+	}
+	errno = -__res;
+	return -1;
+}
+
+void * sbrk(ptrdiff_t increment)
+{
+	char *oldbrk;
+
+	if (increment == 0)
+		return ___brk_addr;
+
+	oldbrk = ___brk_addr;
+	if (brk(oldbrk + increment) < 0)
+		return (char *) -1;
+
+	return oldbrk;
+}
+
+/* Return the value of the environment variable NAME.  */
+char * getenv(register const char *name)
+{
+  register const size_t len = strlen(name);
+  register char **ep;
+
+  for (ep = __environ; *ep != NULL; ++ep)
+    if (!strncmp(*ep, name, len) && (*ep)[len] == '=')
+      return &(*ep)[len + 1];
+
+  return NULL;
+}