62 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
			
		
		
	
	
			62 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
| git-patch-id(1)
 | |
| ===============
 | |
| 
 | |
| NAME
 | |
| ----
 | |
| git-patch-id - Compute unique ID for a patch
 | |
| 
 | |
| SYNOPSIS
 | |
| --------
 | |
| [verse]
 | |
| 'git patch-id' [--stable | --unstable]
 | |
| 
 | |
| DESCRIPTION
 | |
| -----------
 | |
| Read a patch from the standard input and compute the patch ID for it.
 | |
| 
 | |
| A "patch ID" is nothing but a sum of SHA-1 of the file diffs associated with a
 | |
| patch, with whitespace and line numbers ignored.  As such, it's "reasonably
 | |
| stable", but at the same time also reasonably unique, i.e., two patches that
 | |
| have the same "patch ID" are almost guaranteed to be the same thing.
 | |
| 
 | |
| IOW, you can use this thing to look for likely duplicate commits.
 | |
| 
 | |
| When dealing with 'git diff-tree' output, it takes advantage of
 | |
| the fact that the patch is prefixed with the object name of the
 | |
| commit, and outputs two 40-byte hexadecimal strings.  The first
 | |
| string is the patch ID, and the second string is the commit ID.
 | |
| This can be used to make a mapping from patch ID to commit ID.
 | |
| 
 | |
| OPTIONS
 | |
| -------
 | |
| 
 | |
| --stable::
 | |
| 	Use a "stable" sum of hashes as the patch ID. With this option:
 | |
| 	 - Reordering file diffs that make up a patch does not affect the ID.
 | |
| 	   In particular, two patches produced by comparing the same two trees
 | |
| 	   with two different settings for "-O<orderfile>" result in the same
 | |
| 	   patch ID signature, thereby allowing the computed result to be used
 | |
| 	   as a key to index some meta-information about the change between
 | |
| 	   the two trees;
 | |
| 
 | |
| 	 - Result is different from the value produced by git 1.9 and older
 | |
| 	   or produced when an "unstable" hash (see --unstable below) is
 | |
| 	   configured - even when used on a diff output taken without any use
 | |
| 	   of "-O<orderfile>", thereby making existing databases storing such
 | |
| 	   "unstable" or historical patch-ids unusable.
 | |
| 
 | |
| 	This is the default if patchid.stable is set to true.
 | |
| 
 | |
| --unstable::
 | |
| 	Use an "unstable" hash as the patch ID. With this option,
 | |
| 	the result produced is compatible with the patch-id value produced
 | |
| 	by git 1.9 and older.  Users with pre-existing databases storing
 | |
| 	patch-ids produced by git 1.9 and older (who do not deal with reordered
 | |
| 	patches) may want to use this option.
 | |
| 
 | |
| 	This is the default.
 | |
| 
 | |
| GIT
 | |
| ---
 | |
| Part of the linkgit:git[1] suite
 |