linux命令 - touch

功能

change file access and modification times
更新文件的访问时间和修改时间

备注：touch命令也通常用来创建新文件

用法

• touch file - 创建新文件

$ touch file; ls
file

$ touch file1 file2 file3; ls
file1 file2 file3

• touch file - 更新文件的访问、修改时间

$ touch file; stat file
  File: "file"
  Size: 0            FileType: Regular File
  Mode: (0644/-rw-r--r--)         Uid: (  501/zhangjian)  Gid: (   20/   staff)
Device: 1,7   Inode: 3883002    Links: 1
Access: Fri Jul 27 11:03:15 2018
Modify: Fri Jul 27 11:03:15 2018
Change: Fri Jul 27 11:03:15 2018

$ touch file; stat file
  File: "file"
  Size: 0            FileType: Regular File
  Mode: (0644/-rw-r--r--)         Uid: (  501/zhangjian)  Gid: (   20/   staff)
Device: 1,7   Inode: 3883002    Links: 1
Access: Fri Jul 27 11:03:55 2018
Modify: Fri Jul 27 11:03:55 2018
Change: Fri Jul 27 11:03:55 2018

• touch -a file - 只更新文件的访问时间

$ touch file; stat file
  File: "file"
  Size: 0            FileType: Regular File
  Mode: (0644/-rw-r--r--)         Uid: (  501/zhangjian)  Gid: (   20/   staff)
Device: 1,7   Inode: 3883626    Links: 1
Access: Fri Jul 27 11:16:09 2018
Modify: Fri Jul 27 11:16:09 2018
Change: Fri Jul 27 11:16:09 2018

$ touch -a file; stat file
  File: "file"
  Size: 0            FileType: Regular File
  Mode: (0644/-rw-r--r--)         Uid: (  501/zhangjian)  Gid: (   20/   staff)
Device: 1,7   Inode: 3883626    Links: 1
Access: Fri Jul 27 11:16:28 2018
Modify: Fri Jul 27 11:16:09 2018
Change: Fri Jul 27 11:16:28 2018

• touch -m file - 只更新文件的修改时间

$ touch file; stat file
  File: "file"
  Size: 0            FileType: Regular File
  Mode: (0644/-rw-r--r--)         Uid: (  501/zhangjian)  Gid: (   20/   staff)
Device: 1,7   Inode: 3883685    Links: 1
Access: Fri Jul 27 11:18:31 2018
Modify: Fri Jul 27 11:18:31 2018
Change: Fri Jul 27 11:18:31 2018

$ touch -m file; stat file
  File: "file"
  Size: 0            FileType: Regular File
  Mode: (0644/-rw-r--r--)         Uid: (  501/zhangjian)  Gid: (   20/   staff)
Device: 1,7   Inode: 3883685    Links: 1
Access: Fri Jul 27 11:18:31 2018
Modify: Fri Jul 27 11:19:13 2018
Change: Fri Jul 27 11:19:13 2018

Mac用户请使用stat -x file来查看文件状态