$ git ls-tree fb3a8bdd0ce
100644 blob 63c918c667fa005ff12ad89437f2fdc80926e21c .gitignore
100644 blob 5529b198e8d14decbe4ad99db3f7fb632de0439d .mailmap
100644 blob 6ff87c4664981e4397625791c8ea3bbb5f2279a3 COPYING
040000 tree 2fb783e477100ce076f6bf57e4a6f026013dc745 Documentation
100755 blob 3c0032cec592a765692234f1cba47dfdcc3a9200 GIT-VERSION-GEN
100644 blob 289b046a443c0647624607d471289b2c7dcd470b INSTALL
100644 blob 4eb463797adc693dc168b926b6932ff53f17d0b1 Makefile
100644 blob 548142c327a6790ff8821d67c2ee1eff7a656b52 README
...
我知道最后 3 个八位数字是文件模式,但是前 3 个数字是做什么用的? 我在 git 用户手册中找不到它。
来自 gitformat-index(5) / 参考文档 Git 索引文件格式 (1, ²),关于模式:
32-bit mode, split into (high to low bits)
4-bit object type
valid values in binary are 1000 (regular file), 1010 (symbolic link)
and 1110 (gitlink)
3-bit unused
9-bit unix permission. Only 0755 and 0644 are valid for regular files.
Symbolic links and gitlinks have value 0 in this field.
此外,还允许目录对象类型(二进制 0100)和组可写(0664 权限)常规文件,如
fsck.c
fsck_tree
方法所示。常规的不可执行的组可写文件是一种非标准模式,在早期版本的 Git 中已受支持。
这使得有效模式(如二进制和八进制):
0100000000000000
(040000
):目录1000000110100100
(100644
):常规非可执行文件1000000110110100
(100664
):常规非可执行组可写文件1000000111101101
(100755
):常规可执行文件1010000000000000
(120000
):符号链接1110000000000000
(160000
):Gitlink6 位数字使用经典的 UNIX 表示法显示文件模式。 前两位显示文件类型,第三位是关于 set-uid/set-gid/sticky 位,最后三位你知道。
以下是
man 2 stat
在我的 GNU/Linux 系统上记录它的方式:
The following flags are defined for the st_mode field:
S_IFMT 0170000 bit mask for the file type bit fields
S_IFSOCK 0140000 socket
S_IFLNK 0120000 symbolic link
S_IFREG 0100000 regular file
S_IFBLK 0060000 block device
S_IFDIR 0040000 directory
S_IFCHR 0020000 character device
S_IFIFO 0010000 FIFO
S_ISUID 0004000 set UID bit
S_ISGID 0002000 set-group-ID bit (see below)
S_ISVTX 0001000 sticky bit (see below)
S_IRWXU 00700 mask for file owner permissions
S_IRUSR 00400 owner has read permission
S_IWUSR 00200 owner has write permission
S_IXUSR 00100 owner has execute permission
S_IRWXG 00070 mask for group permissions
S_IRGRP 00040 group has read permission
S_IWGRP 00020 group has write permission
S_IXGRP 00010 group has execute permission
S_IRWXO 00007 mask for permissions for others (not in group)
S_IROTH 00004 others have read permission
S_IWOTH 00002 others have write permission
S_IXOTH 00001 others have execute permission
要添加到 Go Dan 的 answer,Git 2.40(2023 年第 1 季度)添加了:
请参阅 Glen Choo (chooglen
)
的commit 3a2ebae(2023 年 2 月 1 日)。
gitster
-- 合并于 commit 2c91b13,2023 年 2 月 9 日)
:在索引“mode”中记录零位docs
签署人:Glen Choo
将“模式”描述为32位,但仅记录16位。Documentation/gitformat-index.txt
记录缺失的 16 位并指定“未使用”位必须为零。
gitformat-index
现在包含在其 手册页中:
16 位未使用,必须为零 ... 3 位未使用,必须为零
这意味着格式实际上是:
0(16x) 0100 000 000000000
(040000
):目录0(16x) 1000 000 110100100
(100644
):常规非可执行文件0(16x) 1000 000 110110100
(100664
):常规非可执行组可写文件0(16x) 1000 000 111101101
(100755
):常规可执行文件0(16x) 1010 000 000000000
(120000
):符号链接0(16x) 1110 000 000000000
(160000
):Gitlink ^^^
always set to 0