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Diffstat (limited to 'Documentation/diff-format.txt')
| -rw-r--r-- | Documentation/diff-format.txt | 264 |
1 files changed, 110 insertions, 154 deletions
diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt index 378e72f38f..85b08909ce 100644 --- a/Documentation/diff-format.txt +++ b/Documentation/diff-format.txt @@ -1,7 +1,10 @@ -The output format from "git-diff-index", "git-diff-tree" and -"git-diff-files" are very similar. +Raw output format +----------------- -These commands all compare two sets of things; what is +The raw output format from "git-diff-index", "git-diff-tree", +"git-diff-files" and "git diff --raw" are very similar. + +These commands all compare two sets of things; what is compared differs: git-diff-index <tree-ish>:: @@ -16,6 +19,9 @@ git-diff-tree [-r] <tree-ish-1> <tree-ish-2> [<pattern>...]:: git-diff-files [<pattern>...]:: compares the index and the files on the filesystem. +The "git-diff-tree" command begins its output by printing the hash of +what is being compared. After that, all the commands print one output +line per changed file. An output line is formatted this way: @@ -46,6 +52,23 @@ That is, from the left to the right: . path for "dst"; only exists for C or R. . an LF or a NUL when '-z' option is used, to terminate the record. +Possible status letters are: + +- A: addition of a file +- C: copy of a file into a new one +- D: deletion of a file +- M: modification of the contents or mode of a file +- R: renaming of a file +- T: change in the type of the file +- U: file is unmerged (you must complete the merge before it can +be committed) +- X: "unknown" change type (most probably a bug, please report it) + +Status letters C and R are always followed by a score (denoting the +percentage of similarity between the source and target of the move or +copy). Status letter M may be followed by a score (denoting the +percentage of dissimilarity) for file rewrites. + <sha1> is shown as all 0's if a file is new on the filesystem and it is out of sync with the index. @@ -59,156 +82,89 @@ When `-z` option is not used, TAB, LF, and backslash characters in pathnames are represented as `\t`, `\n`, and `\\`, respectively. +diff format for merges +---------------------- + +"git-diff-tree", "git-diff-files" and "git-diff --raw" +can take '-c' or '--cc' option +to generate diff output also for merge commits. The output differs +from the format described above in the following way: + +. there is a colon for each parent +. there are more "src" modes and "src" sha1 +. status is concatenated status characters for each parent +. no optional "score" number +. single path, only for "dst" + +Example: + +------------------------------------------------ +::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM describe.c +------------------------------------------------ + +Note that 'combined diff' lists only files which were modified from +all parents. + + +include::diff-generate-patch.txt[] + + +other diff formats +------------------ + +The `--summary` option describes newly added, deleted, renamed and +copied files. The `--stat` option adds diffstat(1) graph to the +output. These options can be combined with other options, such as +`-p`, and are meant for human consumption. + +When showing a change that involves a rename or a copy, `--stat` output +formats the pathnames compactly by combining common prefix and suffix of +the pathnames. For example, a change that moves `arch/i386/Makefile` to +`arch/x86/Makefile` while modifying 4 lines will be shown like this: + +------------------------------------ +arch/{i386 => x86}/Makefile | 4 +-- +------------------------------------ + +The `--numstat` option gives the diffstat(1) information but is designed +for easier machine consumption. An entry in `--numstat` output looks +like this: + +---------------------------------------- +1 2 README +3 1 arch/{i386 => x86}/Makefile +---------------------------------------- + +That is, from left to right: + +. the number of added lines; +. a tab; +. the number of deleted lines; +. a tab; +. pathname (possibly with rename/copy information); +. a newline. + +When `-z` output option is in effect, the output is formatted this way: + +---------------------------------------- +1 2 README NUL +3 1 NUL arch/i386/Makefile NUL arch/x86/Makefile NUL +---------------------------------------- + +That is: -Generating patches with -p --------------------------- - -When "git-diff-index", "git-diff-tree", or "git-diff-files" are run -with a '-p' option, they do not produce the output described above; -instead they produce a patch file. You can customize the creation -of such patches via the GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS -environment variables. - -What the -p option produces is slightly different from the traditional -diff format. - -1. It is preceded with a "git diff" header, that looks like - this: - - diff --git a/file1 b/file2 -+ -The `a/` and `b/` filenames are the same unless rename/copy is -involved. Especially, even for a creation or a deletion, -`/dev/null` is _not_ used in place of `a/` or `b/` filenames. -+ -When rename/copy is involved, `file1` and `file2` show the -name of the source file of the rename/copy and the name of -the file that rename/copy produces, respectively. - -2. It is followed by one or more extended header lines: - - old mode <mode> - new mode <mode> - deleted file mode <mode> - new file mode <mode> - copy from <path> - copy to <path> - rename from <path> - rename to <path> - similarity index <number> - dissimilarity index <number> - index <hash>..<hash> <mode> - -3. TAB, LF, double quote and backslash characters in pathnames - are represented as `\t`, `\n`, `\"` and `\\`, respectively. - If there is need for such substitution then the whole - pathname is put in double quotes. - - -combined diff format --------------------- - -git-diff-tree and git-diff-files can take '-c' or '--cc' option -to produce 'combined diff', which looks like this: - ------------- -diff --combined describe.c -index fabadb8,cc95eb0..4866510 ---- a/describe.c -+++ b/describe.c -@@@ -98,20 -98,12 +98,20 @@@ - return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1; - } - -- static void describe(char *arg) - -static void describe(struct commit *cmit, int last_one) -++static void describe(char *arg, int last_one) - { - + unsigned char sha1[20]; - + struct commit *cmit; - struct commit_list *list; - static int initialized = 0; - struct commit_name *n; - - + if (get_sha1(arg, sha1) < 0) - + usage(describe_usage); - + cmit = lookup_commit_reference(sha1); - + if (!cmit) - + usage(describe_usage); - + - if (!initialized) { - initialized = 1; - for_each_ref(get_name); ------------- - -1. It is preceded with a "git diff" header, that looks like - this (when '-c' option is used): - - diff --combined file -+ -or like this (when '--cc' option is used): - - diff --c file - -2. It is followed by one or more extended header lines - (this example shows a merge with two parents): - - index <hash>,<hash>..<hash> - mode <mode>,<mode>..<mode> - new file mode <mode> - deleted file mode <mode>,<mode> -+ -The `mode <mode>,<mode>..<mode>` line appears only if at least one of -the <mode> is different from the rest. Extended headers with -information about detected contents movement (renames and -copying detection) are designed to work with diff of two -<tree-ish> and are not used by combined diff format. - -3. It is followed by two-line from-file/to-file header - - --- a/file - +++ b/file -+ -Similar to two-line header for traditional 'unified' diff -format, `/dev/null` is used to signal created or deleted -files. - -4. Chunk header format is modified to prevent people from - accidentally feeding it to `patch -p1`. Combined diff format - was created for review of merge commit changes, and was not - meant for apply. The change is similar to the change in the - extended 'index' header: - - @@@ <from-file-range> <from-file-range> <to-file-range> @@@ -+ -There are (number of parents + 1) `@` characters in the chunk -header for combined diff format. - -Unlike the traditional 'unified' diff format, which shows two -files A and B with a single column that has `-` (minus -- -appears in A but removed in B), `+` (plus -- missing in A but -added to B), or `" "` (space -- unchanged) prefix, this format -compares two or more files file1, file2,... with one file X, and -shows how X differs from each of fileN. One column for each of -fileN is prepended to the output line to note how X's line is -different from it. - -A `-` character in the column N means that the line appears in -fileN but it does not appear in the result. A `+` character -in the column N means that the line appears in the last file, -and fileN does not have that line (in other words, the line was -added, from the point of view of that parent). - -In the above example output, the function signature was changed -from both files (hence two `-` removals from both file1 and -file2, plus `++` to mean one line that was added does not appear -in either file1 nor file2). Also two other lines are the same -from file1 but do not appear in file2 (hence prefixed with ` +`). - -When shown by `git diff-tree -c`, it compares the parents of a -merge commit with the merge result (i.e. file1..fileN are the -parents). When shown by `git diff-files -c`, it compares the -two unresolved merge parents with the working tree file -(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka -"their version"). +. the number of added lines; +. a tab; +. the number of deleted lines; +. a tab; +. a NUL (only exists if renamed/copied); +. pathname in preimage; +. a NUL (only exists if renamed/copied); +. pathname in postimage (only exists if renamed/copied); +. a NUL. +The extra `NUL` before the preimage path in renamed case is to allow +scripts that read the output to tell if the current record being read is +a single-path record or a rename/copy record without reading ahead. +After reading added and deleted lines, reading up to `NUL` would yield +the pathname, but if that is `NUL`, the record will show two paths. |