X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=Documentation%2Fdiff-format.txt;h=400cbb3b1c120b93278472678ee7bdb87a74f95b;hb=8e69d78be3f315ea8c7b96400c0c65763b3e8f00;hp=174d63a1ee4238aac88c76daee6f3f1bead0d6b5;hpb=0074aba1c0d3b073c635fdc1d5754dc6a6b6b7b9;p=git.git diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt index 174d63a1e..400cbb3b1 100644 --- a/Documentation/diff-format.txt +++ b/Documentation/diff-format.txt @@ -1,7 +1,7 @@ -The output format from "git-diff-index", "git-diff-tree" and -"git-diff-files" are very similar. +The 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 +These commands all compare two sets of things; what is compared differs: git-diff-index :: @@ -59,199 +59,89 @@ When `-z` option is not used, TAB, LF, and backslash characters in pathnames are represented as `\t`, `\n`, and `\\`, respectively. +diff format for merges +---------------------- -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. - -The patch generation can be customized at two levels. - -1. When the environment variable 'GIT_EXTERNAL_DIFF' is not set, - these commands internally invoke "diff" like this: - - diff -L a/ -L b/ -pu -+ -For added files, `/dev/null` is used for . For removed -files, `/dev/null` is used for -+ -The "diff" formatting options can be customized via the -environment variable 'GIT_DIFF_OPTS'. For example, if you -prefer context diff: - - GIT_DIFF_OPTS=-c git-diff-index -p HEAD - - -2. When the environment variable 'GIT_EXTERNAL_DIFF' is set, the - program named by it is called, instead of the diff invocation - described above. -+ -For a path that is added, removed, or modified, -'GIT_EXTERNAL_DIFF' is called with 7 parameters: - - path old-file old-hex old-mode new-file new-hex new-mode -+ -where: - - -file:: are files GIT_EXTERNAL_DIFF can use to read the - contents of , - -hex:: are the 40-hexdigit SHA1 hashes, - -mode:: are the octal representation of the file modes. - -+ -The file parameters can point at the user's working file -(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file` -when a new file is added), or a temporary file (e.g. `old-file` in the -index). 'GIT_EXTERNAL_DIFF' should not worry about unlinking the -temporary file --- it is removed when 'GIT_EXTERNAL_DIFF' exits. - -For a path that is unmerged, 'GIT_EXTERNAL_DIFF' is called with 1 -parameter, . - - -git specific extension to diff format -------------------------------------- - -What -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 - new mode - deleted file mode - new file mode - copy from - copy to - rename from - rename to - similarity index - dissimilarity index - index .. - -3. TAB, LF, and backslash characters in pathnames are - represented as `\t`, `\n`, and `\\`, respectively. - - -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 ,.. - mode ,.. - new file mode - deleted file mode , -+ -The `mode ,..` line appears only if at least one of -the is diferent from the rest. Extended headers with -information about detected contents movement (renames and -copying detection) are designed to work with diff of two - and are not used by combined diff format. - -3. It is followed by two-line from-file/to-file header - - --- a/file - +++ b/file -+ -Contrary to two-line header for traditional 'unified' diff -format, and similar to filenames in ordinary "diff header", -/dev/null is not used for creation or deletion. - -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: - - @@@ @@@ -+ -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"). +"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: + +. 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.