Q . What does 'git commit' mean when it says 'create mode â¦' on stdout?Dev Singh. asked, Mar 23 ' 2017
Whenerver I commit any new file it says crete mode <any number>.
What is this. Can anybody explain?
Git's ability to store file metadata is limited to a simple subset of information to allow Git to track some basic file system changes allowing Git to track relevant changes for source code management; such as whether a file has been modified and whether a file is a regular file or an executable file.
Git does not try to implement any notion of a file system, leaving file system routines to an actual file system implementation. This makes good sense to allow Git to work equally whether on a FAT32, NTFS, EXT3, XFS, NFS, etc. file system running on Linux, MacOS, Windows, etc.
The 6 digits show the file mode using the classical UNIX notations. First two digits show file type, the third one is about set-uid/set-gid/sticky bits, and you know the last three.
Here is how
man 2 stat documents it on my GNU/Linux system:
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
From the Git
index-format.txt file, regarding the mode:
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.
Also, a directory object type (binary 0100) and group-writeable (0664 permissions) regular file are allowed as indicated by the
fsck_tree method. The regular non-executable group-writeable file is a non-standard mode that was supported in earlier versions of Git.
This makes valid modes (as binary and octal):
100644): Regular non-executable file
100664): Regular non-executable group-writeable file
100755): Regular executable file
120000): Symbolic link