Erlang：在erlang shell中，如何使用write_file_info函数分配文件permssions

Question

我试图使用erlang shell将-rxrxr-x分配给文件file.txt。 但是我们需要在分配给它之前定义一条记录。 而这一切我都想在erlang shell中完成。

谢谢:)

Answer 1

您可以使用rr(Module)在shell从给定的模块加载记录定义。有关详细信息，请参阅shell文档。

例如：

1> rr(file). 
[file_descriptor,file_info] 
2> {ok, Info} = file:read_file_info("hello.erl"). 
{ok,#file_info{size = 0,type = regular,access = read_write, 
      atime = {{2016,11,4},{14,8,35}}, 
      mtime = {{2016,11,4},{14,8,35}}, 
      ctime = {{2016,11,4},{14,8,35}}, 
      mode = 33188,links = 1,major_device = 64512, 
      minor_device = 0,inode = 5769215,uid = 1000,gid = 1000}} 
3> Info2 = Info#file_info{ mode = 8#00600 }. 
#file_info{size = 0,type = regular,access = read_write, 
      atime = {{2016,11,4},{14,8,35}}, 
      mtime = {{2016,11,4},{14,8,35}}, 
      ctime = {{2016,11,4},{14,8,35}}, 
      mode = 384,links = 1,major_device = 64512,minor_device = 0, 
      inode = 5769215,uid = 1000,gid = 1000} 
4> ok = file:write_file_info("hello.erl", Info2).