From 036d731bf29f1a371e4f18245a7498c5a7dcaf73 Mon Sep 17 00:00:00 2001
From: prnmxfqg4 <zimujunxue@163.com>
Date: Mon, 4 Jul 2022 21:04:22 +0800
Subject: [PATCH] ADD file via upload

---
 mysh.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 mysh.c

diff --git a/mysh.c b/mysh.c
new file mode 100644
index 0000000..a25c070
--- /dev/null
+++ b/mysh.c
@@ -0,0 +1,103 @@
+#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>
+#define PATH_MAX        1024
+#define ENOEXEC		 8
+#define MAX_NUMBER_BYTES 1024
+char tmp_path[PATH_MAX+1];
+static char * envp[] = { "HOME=/usr/root", NULL, NULL };
+char ** environ;
+FILE __stdin;
+FILE __stdout;
+_syscall3(pid_t ,waitpid,pid_t ,pid,int * ,wait_stat,int, options)
+_syscall0(int,fork)
+_syscall0(int,pause)
+_syscall0(int,sync)
+_syscall1(int,chdir,const char *, filename)
+_syscall3(int,write,int ,fd,const char *, buf, off_t ,count)
+_syscall3(int, execve,const char *, filename, char **, argv, char ** ,envp)
+_syscall2(int, getcwd,char *, buf, size_t, size)
+_syscall2(int ,access,const char *, filename, mode_t ,mode)
+_syscall3(int,read,int ,fildes,char *, buf, off_t ,count)
+_syscall2(int, stat,const char * ,filename, struct stat *, stat_buf)
+
+
+
+int printf(const char *fmt,...)
+{
+	write(2,fmt,strlen(fmt));
+}
+
+pid_t wait(int * wait_stat)
+{
+	return waitpid(-1,wait_stat,0);
+}
+
+
+
+
+
+void main(int argc, char *argv[])
+{
+	int pid;
+	int status;
+	char dirname[80];
+	char cmdstr[255];
+	int argc_cmd;
+	char *argv_cmd[10];
+	char *p;
+	char a[50];
+
+	while(1)
+	{
+	
+	memset(cmdstr, 0, 255);
+	read(0,cmdstr, strlen(cmdstr));
+	argc_cmd = 0;
+	p = strtok(cmdstr, " \n\t");
+	while (p && argc_cmd < 9){
+		argv_cmd[argc_cmd] = p;
+		p = strtok(NULL, " \n\t");
+		argc_cmd++;
+	}
+	argv_cmd[argc_cmd] = NULL;
+	if (argc_cmd == 0)
+		continue;
+	if (strcmp(argv_cmd[0], "exit") == 0)
+		break;
+	if (strcmp(argv_cmd[0], "sync") == 0){
+		sync();
+		continue;
+	}
+	if (strcmp(argv_cmd[0], "cd") == 0){
+		if ((argc_cmd == 1) || (strcmp(argv_cmd[1], "~") == 0))
+		argv_cmd[1] = "/";
+		if (chdir(argv_cmd[1]) < 0)
+		printf("cd error\n");
+		continue;
+	}
+
+	if (!(pid = fork()))
+	{
+		strcpy(a,"/usr/bin/");
+		strcat(a,argv_cmd[0]);
+		if (execve(a, argv_cmd,envp) == -1)
+		printf("execve error\n");
+		exit(1);
+	}
+	while (1)
+		if (pid == wait(&status))
+		break;
+	
+	}
+	exit(0);
+	
+
+	
+}
+